Do not allow empty messages

.goreleaser.yml

@@ -4,11 +4,9 @@ before:
 builds:
   - binary: ntfy
     env:
-      - CGO_ENABLED=0
+      - CGO_ENABLED=1 # required for go-sqlite3
     goos:
       - linux
-      - windows
-      - darwin
     goarch:
       - amd64
 nfpms:

Makefile

@@ -94,6 +94,7 @@ build-snapshot:
 
 build-simple: clean
 	mkdir -p dist/ntfy_linux_amd64
+	export CGO_ENABLED=1
 	$(GO) build \
 		-o dist/ntfy_linux_amd64/ntfy \
 		-ldflags \

README.md

@@ -1,47 +1,120 @@
-# ntfy
+![ntfy](server/static/img/ntfy.png)
 
-ntfy (pronounce: *notify*) is a super simple pub-sub notification service. It allows you to send desktop and (soon) phone notifications
-via scripts. I run a free version of it on *[ntfy.sh](https://ntfy.sh)*. **No signups or cost.**
+# ntfy.sh | simple HTTP-based pub-sub
+
+**Ntfy** (pronounce: *notify*) is a simple HTTP-based [pub-sub](https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern) notification service.
+It allows you to **send notifications to your phone or desktop via scripts** from any computer, entirely **without signup or cost**.
+It's also open source (as you can plainly see) if you want to run your own.
+
+I run a free version of it at **[ntfy.sh](https://ntfy.sh)**, and there's an [Android app](https://play.google.com/store/apps/details?id=io.heckel.ntfy)
+too.
+
+<p>
+  <img src="server/static/img/screenshot-curl.png" height="180">
+  <img src="server/static/img/screenshot-web-detail.png" height="180">
+  <img src="server/static/img/screenshot-phone-main.jpg" height="180">
+  <img src="server/static/img/screenshot-phone-detail.jpg" height="180">
+  <img src="server/static/img/screenshot-phone-notification.jpg" height="180">
+</p>
 
 ## Usage
 
-### Subscribe to a topic
-Topics are created on the fly by subscribing to them. You can create and subscribe to a topic either in a web UI, or in 
-your own app by subscribing to an [SSE](https://en.wikipedia.org/wiki/Server-sent_events)/[EventSource](https://developer.mozilla.org/en-US/docs/Web/API/EventSource),
-or a JSON or raw feed.  
+### Publishing messages
 
-Because there is no sign-up, **the topic is essentially a password**, so pick something that's not easily guessable.  
+Publishing messages can be done via PUT or POST using. Topics are created on the fly by subscribing or publishing to them.
+Because there is no sign-up, **the topic is essentially a password**, so pick something that's not easily guessable.
 
-Here's how you can create a topic `mytopic`, subscribe to it topic and wait for events. This is using `curl`, but you
-can use any library that can do HTTP GETs:
+Here's an example showing how to publish a message using `curl`:
 
-```
-# Subscribe to "mytopic" and output one message per line (\n are replaced with a space)
-curl -s ntfy.sh/mytopic/raw
-
-# Subscribe to "mytopic" and output one JSON message per line
-curl -s ntfy.sh/mytopic/json
-
-# Subscribe to "mytopic" and output an SSE stream (supported via JS/EventSource)
-curl -s ntfy.sh/mytopic/sse
-```
-
-You can easily script it to execute any command when a message arrives. This sends desktop notifications (just like 
-the web UI, but without it):
-```
-while read msg; do
-  [ -n "$msg" ] && notify-send "$msg"
-done < <(stdbuf -i0 -o0 curl -s ntfy.sh/mytopic/raw)
-```
-
-### Publish messages
-Publishing messages can be done via PUT or POST using. Here's an example using `curl`:
 ```
 curl -d "long process is done" ntfy.sh/mytopic
 ```
 
-Messages published to a non-existing topic or a topic without subscribers will not be delivered later. There is (currently)
-no buffering of any kind. If you're not listening, the message won't be delivered.
+Here's an example in JS with `fetch()` (see [full example](examples)):
+
+```
+fetch('https://ntfy.sh/mytopic', {
+  method: 'POST', // PUT works too
+  body: 'Hello from the other side.'
+})
+```
+
+### Subscribe to a topic
+You can create and subscribe to a topic either in this web UI, or in your own app by subscribing to an
+[EventSource](https://developer.mozilla.org/en-US/docs/Web/API/EventSource), a JSON feed, or raw feed.
+
+#### Subscribe via web
+If you subscribe to a topic via this web UI in the field below, messages published to any subscribed topic
+will show up as **desktop notification**.
+
+You can try this easily on **[ntfy.sh](https://ntfy.sh)**.
+
+#### Subscribe via phone
+You can use the [Ntfy Android App](https://play.google.com/store/apps/details?id=io.heckel.ntfy) to receive 
+notifications directly on your phone. Just like the server, this app is also [open source](https://github.com/binwiederhier/ntfy-android).
+
+#### Subscribe via your app, or via the CLI
+Using [EventSource](https://developer.mozilla.org/en-US/docs/Web/API/EventSource) in JS, you can consume
+notifications like this (see [full example](examples)):
+
+```javascript
+const eventSource = new EventSource('https://ntfy.sh/mytopic/sse');<br/>
+eventSource.onmessage = (e) => {<br/>
+  // Do something with e.data<br/>
+};
+```
+
+You can also use the same `/sse` endpoint via `curl` or any other HTTP library:
+
+```
+$ curl -s ntfy.sh/mytopic/sse
+event: open
+data: {"id":"weSj9RtNkj","time":1635528898,"event":"open","topic":"mytopic"}
+
+data: {"id":"p0M5y6gcCY","time":1635528909,"event":"message","topic":"mytopic","message":"Hi!"}
+
+event: keepalive
+data: {"id":"VNxNIg5fpt","time":1635528928,"event":"keepalive","topic":"test"}
+```
+
+To consume JSON instead, use the `/json` endpoint, which prints one message per line:
+
+```
+$ curl -s ntfy.sh/mytopic/json
+{"id":"SLiKI64DOt","time":1635528757,"event":"open","topic":"mytopic"}
+{"id":"hwQ2YpKdmg","time":1635528741,"event":"message","topic":"mytopic","message":"Hi!"}
+{"id":"DGUDShMCsc","time":1635528787,"event":"keepalive","topic":"mytopic"}
+```
+
+Or use the `/raw` endpoint if you need something super simple (empty lines are keepalive messages):
+
+```
+$ curl -s ntfy.sh/mytopic/raw
+
+This is a notification
+```
+
+#### Message buffering and polling
+Messages are buffered in memory for a few hours to account for network interruptions of subscribers.
+You can read back what you missed by using the `since=...` query parameter. It takes either a
+duration (e.g. `10m` or `30s`) or a Unix timestamp (e.g. `1635528757`):
+
+```
+$ curl -s "ntfy.sh/mytopic/json?since=10m"
+# Same output as above, but includes messages from up to 10 minutes ago
+```
+
+You can also just poll for messages if you don't like the long-standing connection using the `poll=1`
+query parameter. The connection will end after all available messages have been read. This parameter has to be
+combined with `since=`.
+
+```
+$ curl -s "ntfy.sh/mytopic/json?poll=1&since=10m"
+# Returns messages from up to 10 minutes ago and ends the connection
+```
+
+## Examples
+There are a few usage examples in the [examples](examples) directory. I'm sure there are tons of other ways to use it.
 
 ## Installation
 Please check out the [releases page](https://github.com/binwiederhier/ntfy/releases) for binaries and
@@ -64,13 +137,13 @@ sudo apt install ntfy
 **Debian/Ubuntu** (*manual install*)**:**
 ```bash
 sudo apt install tmux
-wget https://github.com/binwiederhier/ntfy/releases/download/v1.1.2/ntfy_1.1.2_amd64.deb
-dpkg -i ntfy_1.1.2_amd64.deb
+wget https://github.com/binwiederhier/ntfy/releases/download/v1.4.0/ntfy_1.3.0_amd64.deb
+dpkg -i ntfy_1.4.0_amd64.deb
 ```
 
 **Fedora/RHEL/CentOS:**
 ```bash
-rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.1.2/ntfy_1.1.2_amd64.rpm
+rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.4.0/ntfy_1.3.0_amd64.rpm
 ```
 
 **Docker:**
@@ -85,8 +158,8 @@ go get -u heckel.io/ntfy
 
 **Manual install** (*any x86_64-based Linux*)**:**
 ```bash
-wget https://github.com/binwiederhier/ntfy/releases/download/v1.1.2/ntfy_1.1.2_linux_x86_64.tar.gz
-sudo tar -C /usr/bin -zxf ntfy_1.1.2_linux_x86_64.tar.gz ntfy
+wget https://github.com/binwiederhier/ntfy/releases/download/v1.4.0/ntfy_1.3.0_linux_x86_64.tar.gz
+sudo tar -C /usr/bin -zxf ntfy_1.4.0_linux_x86_64.tar.gz ntfy
 ./ntfy
 ```
 
@@ -104,7 +177,6 @@ To build releases, I use [GoReleaser](https://goreleaser.com/). If you have that
 ## TODO
 - add HTTPS
 - make limits configurable
-- limit max number of subscriptions 
 
 ## Contributing
 I welcome any and all contributions. Just create a PR or an issue.
@@ -116,4 +188,7 @@ Third party libraries and resources:
 * [github.com/urfave/cli/v2](https://github.com/urfave/cli/v2) (MIT) is used to drive the CLI
 * [Mixkit sound](https://mixkit.co/free-sound-effects/notification/) (Mixkit Free License) used as notification sound
 * [Lato Font](https://www.latofonts.com/) (OFL) is used as a font in the Web UI
-* [GoReleaser](https://goreleaser.com/) (MIT) is used to create releases 
+* [GoReleaser](https://goreleaser.com/) (MIT) is used to create releases
+* [github.com/mattn/go-sqlite3](https://github.com/mattn/go-sqlite3) (MIT) is used to provide the persistent message cache
+* [Firebase Admin SDK](https://github.com/firebase/firebase-admin-go) (Apache 2.0) is used to send FCM messages
+* [Lightbox with vanilla JS](https://yossiabramov.com/blog/vanilla-js-lightbox) 

cmd/app.go

@@ -20,9 +20,15 @@ func New() *cli.App {
 		&cli.StringFlag{Name: "config", Aliases: []string{"c"}, EnvVars: []string{"NTFY_CONFIG_FILE"}, Value: "/etc/ntfy/config.yml", DefaultText: "/etc/ntfy/config.yml", Usage: "config file"},
 		altsrc.NewStringFlag(&cli.StringFlag{Name: "listen-http", Aliases: []string{"l"}, EnvVars: []string{"NTFY_LISTEN_HTTP"}, Value: config.DefaultListenHTTP, Usage: "ip:port used to as listen address"}),
 		altsrc.NewStringFlag(&cli.StringFlag{Name: "firebase-key-file", Aliases: []string{"F"}, EnvVars: []string{"NTFY_FIREBASE_KEY_FILE"}, Usage: "Firebase credentials file; if set additionally publish to FCM topic"}),
-		altsrc.NewDurationFlag(&cli.DurationFlag{Name: "message-buffer-duration", Aliases: []string{"b"}, EnvVars: []string{"NTFY_MESSAGE_BUFFER_DURATION"}, Value: config.DefaultMessageBufferDuration, Usage: "buffer messages in memory for this time to allow `since` requests"}),
-		altsrc.NewDurationFlag(&cli.DurationFlag{Name: "keepalive-interval", Aliases: []string{"k"}, EnvVars: []string{"NTFY_KEEPALIVE_INTERVAL"}, Value: config.DefaultKeepaliveInterval, Usage: "default interval of keepalive messages"}),
-		altsrc.NewDurationFlag(&cli.DurationFlag{Name: "manager-interval", Aliases: []string{"m"}, EnvVars: []string{"NTFY_MANAGER_INTERVAL"}, Value: config.DefaultManagerInterval, Usage: "default interval of for message pruning and stats printing"}),
+		altsrc.NewStringFlag(&cli.StringFlag{Name: "cache-file", Aliases: []string{"C"}, EnvVars: []string{"NTFY_CACHE_FILE"}, Usage: "cache file used for message caching"}),
+		altsrc.NewDurationFlag(&cli.DurationFlag{Name: "cache-duration", Aliases: []string{"b"}, EnvVars: []string{"NTFY_CACHE_DURATION"}, Value: config.DefaultCacheDuration, Usage: "buffer messages for this time to allow `since` requests"}),
+		altsrc.NewDurationFlag(&cli.DurationFlag{Name: "keepalive-interval", Aliases: []string{"k"}, EnvVars: []string{"NTFY_KEEPALIVE_INTERVAL"}, Value: config.DefaultKeepaliveInterval, Usage: "interval of keepalive messages"}),
+		altsrc.NewDurationFlag(&cli.DurationFlag{Name: "manager-interval", Aliases: []string{"m"}, EnvVars: []string{"NTFY_MANAGER_INTERVAL"}, Value: config.DefaultManagerInterval, Usage: "interval of for message pruning and stats printing"}),
+		altsrc.NewIntFlag(&cli.IntFlag{Name: "global-topic-limit", Aliases: []string{"T"}, EnvVars: []string{"NTFY_GLOBAL_TOPIC_LIMIT"}, Value: config.DefaultGlobalTopicLimit, Usage: "total number of topics allowed"}),
+		altsrc.NewIntFlag(&cli.IntFlag{Name: "visitor-subscription-limit", Aliases: []string{"V"}, EnvVars: []string{"NTFY_VISITOR_SUBSCRIPTION_LIMIT"}, Value: config.DefaultVisitorSubscriptionLimit, Usage: "number of subscriptions per visitor"}),
+		altsrc.NewIntFlag(&cli.IntFlag{Name: "visitor-request-limit-burst", Aliases: []string{"B"}, EnvVars: []string{"NTFY_VISITOR_REQUEST_LIMIT_BURST"}, Value: config.DefaultVisitorRequestLimitBurst, Usage: "initial limit of requests per visitor"}),
+		altsrc.NewDurationFlag(&cli.DurationFlag{Name: "visitor-request-limit-replenish", Aliases: []string{"R"}, EnvVars: []string{"NTFY_VISITOR_REQUEST_LIMIT_REPLENISH"}, Value: config.DefaultVisitorRequestLimitReplenish, Usage: "interval at which burst limit is replenished (one per x)"}),
+		altsrc.NewBoolFlag(&cli.BoolFlag{Name: "behind-proxy", Aliases: []string{"P"}, EnvVars: []string{"NTFY_BEHIND_PROXY"}, Value: false, Usage: "if set, use X-Forwarded-For header to determine visitor IP address (for rate limiting)"}),
 	}
 	return &cli.App{
 		Name:                   "ntfy",
@@ -45,9 +51,15 @@ func execRun(c *cli.Context) error {
 	// Read all the options
 	listenHTTP := c.String("listen-http")
 	firebaseKeyFile := c.String("firebase-key-file")
-	messageBufferDuration := c.Duration("message-buffer-duration")
+	cacheFile := c.String("cache-file")
+	cacheDuration := c.Duration("cache-duration")
 	keepaliveInterval := c.Duration("keepalive-interval")
 	managerInterval := c.Duration("manager-interval")
+	globalTopicLimit := c.Int("global-topic-limit")
+	visitorSubscriptionLimit := c.Int("visitor-subscription-limit")
+	visitorRequestLimitBurst := c.Int("visitor-request-limit-burst")
+	visitorRequestLimitReplenish := c.Duration("visitor-request-limit-replenish")
+	behindProxy := c.Bool("behind-proxy")
 
 	// Check values
 	if firebaseKeyFile != "" && !util.FileExists(firebaseKeyFile) {
@@ -56,16 +68,22 @@ func execRun(c *cli.Context) error {
 		return errors.New("keepalive interval cannot be lower than five seconds")
 	} else if managerInterval < 5*time.Second {
 		return errors.New("manager interval cannot be lower than five seconds")
-	} else if messageBufferDuration < managerInterval {
-		return errors.New("message buffer duration cannot be lower than manager interval")
+	} else if cacheDuration < managerInterval {
+		return errors.New("cache duration cannot be lower than manager interval")
 	}
 
 	// Run server
 	conf := config.New(listenHTTP)
 	conf.FirebaseKeyFile = firebaseKeyFile
-	conf.MessageBufferDuration = messageBufferDuration
+	conf.CacheFile = cacheFile
+	conf.CacheDuration = cacheDuration
 	conf.KeepaliveInterval = keepaliveInterval
 	conf.ManagerInterval = managerInterval
+	conf.GlobalTopicLimit = globalTopicLimit
+	conf.VisitorSubscriptionLimit = visitorSubscriptionLimit
+	conf.VisitorRequestLimitBurst = visitorRequestLimitBurst
+	conf.VisitorRequestLimitReplenish = visitorRequestLimitReplenish
+	conf.BehindProxy = behindProxy
 	s, err := server.New(conf)
 	if err != nil {
 		log.Fatalln(err)

config/config.go

@@ -2,53 +2,56 @@
 package config
 
 import (
-	"golang.org/x/time/rate"
 	"time"
 )
 
 // Defines default config settings
 const (
-	DefaultListenHTTP            = ":80"
-	DefaultMessageBufferDuration = 12 * time.Hour
-	DefaultKeepaliveInterval     = 30 * time.Second
-	DefaultManagerInterval       = time.Minute
+	DefaultListenHTTP        = ":80"
+	DefaultCacheDuration     = 12 * time.Hour
+	DefaultKeepaliveInterval = 30 * time.Second
+	DefaultManagerInterval   = time.Minute
 )
 
 // Defines all the limits
-// - request limit: max number of PUT/GET/.. requests (here: 50 requests bucket, replenished at a rate of 1 per second)
 // - global topic limit: max number of topics overall
-// - subscription limit: max number of subscriptions (active HTTP connections) per per-visitor/IP
-var (
-	defaultGlobalTopicLimit         = 5000
-	defaultVisitorRequestLimit      = rate.Every(time.Second)
-	defaultVisitorRequestLimitBurst = 50
-	defaultVisitorSubscriptionLimit = 30
+// - per visistor request limit: max number of PUT/GET/.. requests (here: 60 requests bucket, replenished at a rate of one per 10 seconds)
+// - per visistor subscription limit: max number of subscriptions (active HTTP connections) per per-visitor/IP
+const (
+	DefaultGlobalTopicLimit             = 5000
+	DefaultVisitorRequestLimitBurst     = 60
+	DefaultVisitorRequestLimitReplenish = 10 * time.Second
+	DefaultVisitorSubscriptionLimit     = 30
 )
 
 // Config is the main config struct for the application. Use New to instantiate a default config struct.
 type Config struct {
-	ListenHTTP               string
-	FirebaseKeyFile          string
-	MessageBufferDuration    time.Duration
-	KeepaliveInterval        time.Duration
-	ManagerInterval          time.Duration
-	GlobalTopicLimit         int
-	VisitorRequestLimit      rate.Limit
-	VisitorRequestLimitBurst int
-	VisitorSubscriptionLimit int
+	ListenHTTP                   string
+	FirebaseKeyFile              string
+	CacheFile                    string
+	CacheDuration                time.Duration
+	KeepaliveInterval            time.Duration
+	ManagerInterval              time.Duration
+	GlobalTopicLimit             int
+	VisitorRequestLimitBurst     int
+	VisitorRequestLimitReplenish time.Duration
+	VisitorSubscriptionLimit     int
+	BehindProxy                  bool
 }
 
 // New instantiates a default new config
 func New(listenHTTP string) *Config {
 	return &Config{
-		ListenHTTP:               listenHTTP,
-		FirebaseKeyFile:          "",
-		MessageBufferDuration:    DefaultMessageBufferDuration,
-		KeepaliveInterval:        DefaultKeepaliveInterval,
-		ManagerInterval:          DefaultManagerInterval,
-		GlobalTopicLimit:         defaultGlobalTopicLimit,
-		VisitorRequestLimit:      defaultVisitorRequestLimit,
-		VisitorRequestLimitBurst: defaultVisitorRequestLimitBurst,
-		VisitorSubscriptionLimit: defaultVisitorSubscriptionLimit,
+		ListenHTTP:                   listenHTTP,
+		FirebaseKeyFile:              "",
+		CacheFile:                    "",
+		CacheDuration:                DefaultCacheDuration,
+		KeepaliveInterval:            DefaultKeepaliveInterval,
+		ManagerInterval:              DefaultManagerInterval,
+		GlobalTopicLimit:             DefaultGlobalTopicLimit,
+		VisitorRequestLimitBurst:     DefaultVisitorRequestLimitBurst,
+		VisitorRequestLimitReplenish: DefaultVisitorRequestLimitReplenish,
+		VisitorSubscriptionLimit:     DefaultVisitorSubscriptionLimit,
+		BehindProxy:                  false,
 	}
 }

config/config.yml

@@ -10,16 +10,45 @@
 #
 # firebase-key-file: <filename>
 
+# If set, messages are cached in a local SQLite database instead of only in-memory. This
+# allows for service restarts without losing messages in support of the since= parameter.
+#
+# cache-file: <filename>
+
 # Duration for which messages will be buffered before they are deleted.
 # This is required to support the "since=..." and "poll=1" parameter.
 #
-# message-buffer-duration: 12h
+# cache-duration: 12h
 
 # Interval in which keepalive messages are sent to the client. This is to prevent
 # intermediaries closing the connection for inactivity.
 #
 # keepalive-interval: 30s
 
-# Interval in which the manager prunes old messages, deletes topics and prints the stats.
+# Interval in which the manager prunes old messages, deletes topics
+# and prints the stats.
 #
 # manager-interval: 1m
+
+# Rate limiting: Total number of topics before the server rejects new topics.
+#
+# global-topic-limit: 5000
+
+# Rate limiting: Number of subscriptions per visitor (IP address)
+#
+# visitor-subscription-limit: 30
+
+# Rate limiting: Allowed GET/PUT/POST requests per second, per visitor:
+# - visitor-request-limit-burst is the initial bucket of requests each visitor has
+# - visitor-request-limit-replenish is the rate at which the bucket is refilled
+#
+# visitor-request-limit-burst: 60
+# visitor-request-limit-replenish: 10s
+
+# If set, the X-Forwarded-For header is used to determine the visitor IP address
+# instead of the remote address of the connection.
+#
+# WARNING: If you are behind a proxy, you must set this, otherwise all visitors are rate limited
+#          as if they are one.
+#
+# behind-proxy: false

examples/linux-desktop-notifications/notify-desktop.sh

@@ -3,5 +3,5 @@
 # a simple script. The notify-send command sends any arriving message as a desktop notification.
 
 while read msg; do
-  notify-send "$msg"
+  [ -n "$msg" ] && notify-send "$msg"
 done < <(stdbuf -i0 -o0 curl -s ntfy.sh/mytopic/raw)

examples/ssh-login-alert/ntfy-ssh-login.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+# This is a PAM script hook that shows how to notify you when
+# somebody logs into your server. Place at /usr/local/bin/ntfy-ssh-login.sh (with chmod +x!).
+
+if [ "${PAM_TYPE}" = "open_session" ]; then
+  echo -en "\u26A0\uFE0F SSH login to $(hostname): ${PAM_USER} from ${PAM_RHOST}" | curl -T- ntfy.sh/alerts
+fi

examples/ssh-login-alert/pam_sshd

@@ -0,0 +1,8 @@
+# PAM config file snippet
+#
+# Put this snippet AT THE END of the file /etc/pam.d/sshd
+# See https://geekthis.net/post/run-scripts-after-ssh-authentication/ for details.
+
+# (lots of stuff here ...)
+
+session optional pam_exec.so /usr/local/bin/ntfy-ssh-login.sh

examples/web-example-eventsource/example-ssh.html

@@ -3,6 +3,7 @@
 <head>
     <meta charset="UTF-8">
     <title>ntfy.sh: EventSource Example</title>
+    <meta name="robots" content="noindex, nofollow" />
     <style>
         body { font-size: 1.2em; line-height: 130%; }
         #events { font-family: monospace; }
@@ -13,6 +14,7 @@
 <p>
     This is an example showing how to use <a href="https://ntfy.sh">ntfy.sh</a> with
     <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a>.<br/>
+    This example doesn't need a server. You can just save the HTML page and run it from anywhere.
 </p>
 <button id="publishButton">Send test notification</button>
 <p><b>Log:</b></p>

go.mod

@@ -1,16 +1,42 @@
 module heckel.io/ntfy
 
-go 1.16
+go 1.17
 
 require (
-	cloud.google.com/go/firestore v1.6.0 // indirect
+	cloud.google.com/go/firestore v1.6.1 // indirect
 	cloud.google.com/go/storage v1.18.2 // indirect
 	firebase.google.com/go v3.13.0+incompatible
 	github.com/BurntSushi/toml v0.4.1 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.1 // indirect
+	github.com/mattn/go-sqlite3 v1.14.9
 	github.com/urfave/cli/v2 v2.3.0
 	golang.org/x/oauth2 v0.0.0-20211028175245-ba495a64dcb5 // indirect
 	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac
 	google.golang.org/api v0.60.0
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )
+
+require (
+	cloud.google.com/go v0.97.0 // indirect
+	github.com/census-instrumentation/opencensus-proto v0.3.0 // indirect
+	github.com/cespare/xxhash v1.1.0 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/cncf/udpa/go v0.0.0-20210930031921-04548b0d99d4 // indirect
+	github.com/cncf/xds/go v0.0.0-20211011173535-cb28da3451f1 // indirect
+	github.com/envoyproxy/go-control-plane v0.10.0 // indirect
+	github.com/envoyproxy/protoc-gen-validate v0.6.2 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/go-cmp v0.5.6 // indirect
+	github.com/googleapis/gax-go/v2 v2.1.1 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	go.opencensus.io v0.23.0 // indirect
+	golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d // indirect
+	golang.org/x/sys v0.0.0-20211025201205-69cdffdb9359 // indirect
+	golang.org/x/text v0.3.7 // indirect
+	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/genproto v0.0.0-20211101144312-62acf1d99145 // indirect
+	google.golang.org/grpc v1.41.0 // indirect
+	google.golang.org/protobuf v1.27.1 // indirect
+)

go.sum

@@ -36,6 +36,8 @@ cloud.google.com/go/datastore v1.0.0/go.mod h1:LXYbyblFSglQ5pkeyhO+Qmw7ukd3C+pD7
 cloud.google.com/go/datastore v1.1.0/go.mod h1:umbIZjpQpHh4hmRpGhH4tLFup+FVzqBi1b3c64qFpCk=
 cloud.google.com/go/firestore v1.6.0 h1:dMIWvm+3O0E3DM7kcZPH0FBQ94Xg/OMkdTNDaY9itbI=
 cloud.google.com/go/firestore v1.6.0/go.mod h1:afJwI0vaXwAG54kI7A//lP/lSPDkQORQuMkv56TxEPU=
+cloud.google.com/go/firestore v1.6.1 h1:8rBq3zRjnHx8UtBvaOWqBB1xq9jH6/wltfQLlTMh2Fw=
+cloud.google.com/go/firestore v1.6.1/go.mod h1:asNXNOzBdyVQmEU+ggO8UPodTkEVFW5Qx+rwHnAz+EY=
 cloud.google.com/go/pubsub v1.0.1/go.mod h1:R0Gpsv3s54REJCy4fxDixWD93lHJMoZTyQ2kNxGRt3I=
 cloud.google.com/go/pubsub v1.1.0/go.mod h1:EwwdRX2sKPjnvnqCa270oGRyludottCI76h+R3AArQw=
 cloud.google.com/go/pubsub v1.2.0/go.mod h1:jhfEVHT8odbXTkndysNHCcx0awwzvfOlguIAii9o8iA=
@@ -59,8 +61,13 @@ github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAE
 github.com/antihax/optional v1.0.0/go.mod h1:uupD/76wgC+ih3iEmQUL+0Ugr19nfwCT1kdvxnR2qWY=
 github.com/census-instrumentation/opencensus-proto v0.2.1 h1:glEXhBS5PSLLv4IXzLA5yPRVX4bilULVyxxbrfOtDAk=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/census-instrumentation/opencensus-proto v0.3.0 h1:t/LhUZLVitR1Ow2YOnduCsavhwFUklBMoGVYUCqmCqk=
+github.com/census-instrumentation/opencensus-proto v0.3.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
+github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/cespare/xxhash/v2 v2.1.2 h1:YRXhKfTDauu4ajMg1TPgFO5jnlC2HCbmLXMcTG5cbYE=
+github.com/cespare/xxhash/v2 v2.1.2/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
@@ -69,8 +76,15 @@ github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGX
 github.com/cncf/udpa/go v0.0.0-20200629203442-efcf912fb354/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
 github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403 h1:cqQfy1jclcSy/FwLjemeg3SR1yaINm74aQyupQ0Bl8M=
 github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
+github.com/cncf/udpa/go v0.0.0-20210930031921-04548b0d99d4 h1:hzAQntlaYRkVSFEfj9OTWlVV1H155FMD8BTKktLv0QI=
+github.com/cncf/udpa/go v0.0.0-20210930031921-04548b0d99d4/go.mod h1:6pvJx4me5XPnfI9Z40ddWsdw2W/uZgQLFXToKeRcDiI=
 github.com/cncf/xds/go v0.0.0-20210312221358-fbca930ec8ed h1:OZmjad4L3H8ncOIR8rnb5MREYqG8ixi5+WbeUsquF0c=
 github.com/cncf/xds/go v0.0.0-20210312221358-fbca930ec8ed/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
+github.com/cncf/xds/go v0.0.0-20210805033703-aa0b78936158/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
+github.com/cncf/xds/go v0.0.0-20210922020428-25de7278fc84/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
+github.com/cncf/xds/go v0.0.0-20211001041855-01bcc9b48dfe/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
+github.com/cncf/xds/go v0.0.0-20211011173535-cb28da3451f1 h1:zH8ljVhhq7yC0MIeUL/IviMtY8hx2mK8cN9wEYb8ggw=
+github.com/cncf/xds/go v0.0.0-20211011173535-cb28da3451f1/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1 h1:r/myEWzV9lfsM1tFLgDyu0atFtJ1fXn261LKYj/3DxU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
@@ -83,8 +97,13 @@ github.com/envoyproxy/go-control-plane v0.9.9-0.20201210154907-fd9021fe5dad/go.m
 github.com/envoyproxy/go-control-plane v0.9.9-0.20210217033140-668b12f5399d/go.mod h1:cXg6YxExXjJnVBQHBLXeUAgxn2UodCpnH306RInaBQk=
 github.com/envoyproxy/go-control-plane v0.9.9-0.20210512163311-63b5d3c536b0 h1:dulLQAYQFYtG5MTplgNGHWuV2D+OBD+Z8lmDBmbLg+s=
 github.com/envoyproxy/go-control-plane v0.9.9-0.20210512163311-63b5d3c536b0/go.mod h1:hliV/p42l8fGbc6Y9bQ70uLwIvmJyVE5k4iMKlh8wCQ=
+github.com/envoyproxy/go-control-plane v0.9.10-0.20210907150352-cf90f659a021/go.mod h1:AFq3mo9L8Lqqiid3OhADV3RfLJnjiw63cSpi+fDTRC0=
+github.com/envoyproxy/go-control-plane v0.10.0 h1:WVt4HEPbdRbRD/PKKPbPnIVavO6gk/h673jWyIJ016k=
+github.com/envoyproxy/go-control-plane v0.10.0/go.mod h1:AY7fTTXNdv/aJ2O5jwpxAPOWUZ7hQAEvzN5Pf27BkQQ=
 github.com/envoyproxy/protoc-gen-validate v0.1.0 h1:EQciDnbrYxy13PgWoY8AqoxGiPrpgBZ1R8UNe3ddc+A=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
+github.com/envoyproxy/protoc-gen-validate v0.6.2 h1:JiO+kJTpmYGjEodY7O1Zk8oZcNz1+f30UtwtXoFUPzE=
+github.com/envoyproxy/protoc-gen-validate v0.6.2/go.mod h1:2t7qjJNvHPx8IjnBOzl9E9/baC+qXE/TeeyBRzgJDws=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
@@ -94,6 +113,8 @@ github.com/golang/groupcache v0.0.0-20190702054246-869f871628b6/go.mod h1:cIg4er
 github.com/golang/groupcache v0.0.0-20191227052852-215e87163ea7/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e h1:1r7pUrabqp18hOBcwBwiTsbnFeTZHV9eER/QT5JVZxY=
 github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l8iNU+DwB5epxmsaqB+rhGL0m5jtYqE=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/mock v1.2.0/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/mock v1.3.1/go.mod h1:sBzyDLLjw3U8JLTeZvSv8jJB+tU5PVekmnlKIyFUx0Y=
@@ -168,16 +189,24 @@ github.com/googleapis/gax-go/v2 v2.1.1/go.mod h1:hddJymUZASv3XPyGkUpKj8pPO47Rmb0
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/iancoleman/strcase v0.2.0/go.mod h1:iwCmte+B7n89clKwxIoIXy/HfoL7AsD47ZCWhYzw7ho=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/XSXhF0NWZEnDohbsk=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/kr/fs v0.1.0/go.mod h1:FFnZGqtBN9Gxj7eW1uZ42v5BccTP0vu6NEaFoC2HwRg=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/lyft/protoc-gen-star v0.5.3/go.mod h1:V0xaHgaf5oCCqmcxYcWiDfTiKsZsRc87/1qhoTACD8w=
+github.com/mattn/go-sqlite3 v1.14.8/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
+github.com/mattn/go-sqlite3 v1.14.9 h1:10HX2Td0ocZpYEjhilsuo6WWtUqttj2Kb0KtD86/KYA=
+github.com/mattn/go-sqlite3 v1.14.9/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/sftp v1.10.1/go.mod h1:lYOWFsE0bwd1+KfKJaKeuokY15vzFx25BLbzYYoAxZI=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
@@ -188,10 +217,13 @@ github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQD
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72 h1:qLC7fQah7D6K1B0ujays3HV9gkFtllcxhzImRR7ArPQ=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
+github.com/spf13/afero v1.3.3/go.mod h1:5KUK8ByomD5Ti5Artl0RtHeI5pTF7MIDuXL3yY520V4=
+github.com/spf13/afero v1.6.0/go.mod h1:Ai8FlHk4v/PARR026UzYexafAt9roJ7LcLMAmO6Z93I=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/urfave/cli/v2 v2.3.0 h1:qph92Y649prgesehzOrQjdWyxFOp/QVM+6imKHad91M=
 github.com/urfave/cli/v2 v2.3.0/go.mod h1:LJmUH05zAU44vOAcrfzZQKsZbVcdbOG8rtL3/XcUArI=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -211,6 +243,7 @@ go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqe
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190605123033-f99c8df09eb5/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
@@ -248,6 +281,7 @@ golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.5.0/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -284,6 +318,8 @@ golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4/go.mod h1:RBQZq4jEuRlivfhVLd
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420 h1:a8jGStKg0XqKDlKqjLrXn0ioF5MH36pT7Z0BRTqLhbk=
 golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d h1:LO7XpTYMwTqxjLcGWPijK3vRXg1aWdlNOVOHRq45d7c=
+golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -356,9 +392,11 @@ golang.org/x/sys v0.0.0-20210603125802-9665404d3644/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210616094352-59db8d763f22/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210806184541-e5e7981a1069/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210816183151-1e6c022a8912/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210823070655-63515b42dcdf/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210908233432-aa78b53d3365/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210917161153-d61c044b1678/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211025201205-69cdffdb9359 h1:2B5p2L5IfGiD7+b9BOoRMC6DgObAVZV+Fsp050NqXik=
 golang.org/x/sys v0.0.0-20211025201205-69cdffdb9359/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -371,6 +409,8 @@ golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6 h1:aRYxNxv6iGQlyVaZmk6ZgYEDa+Jg18DxebPSrd6bg1M=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
@@ -462,6 +502,7 @@ google.golang.org/api v0.55.0/go.mod h1:38yMfeP1kfjsl8isn0tliTjIb1rJXcQi4UXlbqiv
 google.golang.org/api v0.56.0/go.mod h1:38yMfeP1kfjsl8isn0tliTjIb1rJXcQi4UXlbqivdVE=
 google.golang.org/api v0.57.0/go.mod h1:dVPlbZyBo2/OjBpmvNdpn2GRm6rPy75jyU7bmhdrMgI=
 google.golang.org/api v0.58.0/go.mod h1:cAbP2FsxoGVNwtgNAmmn3y5G1TWAiVYRmg4yku3lv+E=
+google.golang.org/api v0.59.0/go.mod h1:sT2boj7M9YJxZzgeZqXogmhfmRWDtPzT31xkieUbuZU=
 google.golang.org/api v0.60.0 h1:eq/zs5WPH4J9undYM9IP1O7dSr7Yh8Y0GtSCpzGzIUk=
 google.golang.org/api v0.60.0/go.mod h1:d7rl65NZAkEQ90JFzqBjcRq1TVeG5ZoGV3sSpEnnVb4=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
@@ -529,9 +570,13 @@ google.golang.org/genproto v0.0.0-20210903162649-d08c68adba83/go.mod h1:eFjDcFEc
 google.golang.org/genproto v0.0.0-20210909211513-a8c4777a87af/go.mod h1:eFjDcFEctNawg4eG61bRv87N7iHBWyVhJu7u1kqDUXY=
 google.golang.org/genproto v0.0.0-20210917145530-b395a37504d4/go.mod h1:eFjDcFEctNawg4eG61bRv87N7iHBWyVhJu7u1kqDUXY=
 google.golang.org/genproto v0.0.0-20210924002016-3dee208752a0/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
+google.golang.org/genproto v0.0.0-20211008145708-270636b82663/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211016002631-37fc39342514/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211021150943-2b146023228c h1:FqrtZMB5Wr+/RecOM3uPJNPfWR8Upb5hAPnt7PU6i4k=
 google.golang.org/genproto v0.0.0-20211021150943-2b146023228c/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
+google.golang.org/genproto v0.0.0-20211028162531-8db9c33dc351/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
+google.golang.org/genproto v0.0.0-20211101144312-62acf1d99145 h1:vum3nDKdleYb+aePXKFEDT2+ghuH00EgYp9B7Q7EZZE=
+google.golang.org/genproto v0.0.0-20211101144312-62acf1d99145/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
 google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
@@ -558,6 +603,8 @@ google.golang.org/grpc v1.39.0/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnD
 google.golang.org/grpc v1.39.1/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnDzfrE=
 google.golang.org/grpc v1.40.0 h1:AGJ0Ih4mHjSeibYkFGh1dD9KJ/eOtZ93I6hoHhukQ5Q=
 google.golang.org/grpc v1.40.0/go.mod h1:ogyxbiOoUXAkP+4+xa6PZSE9DZgIHtSpzjDTB9KAK34=
+google.golang.org/grpc v1.41.0 h1:f+PlOh7QV4iIJkPrx5NQ7qaNGFQ3OTse67yaDHfju4E=
+google.golang.org/grpc v1.41.0/go.mod h1:U3l9uK9J0sini8mHphKoXyaqDA/8VyGnDee1zzIUK6k=
 google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.1.0/go.mod h1:6Kw0yEErY5E/yWrBtf03jp27GLLJujG4z/JK95pnjjw=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=

server/cache.go

@@ -0,0 +1,14 @@
+package server
+
+import (
+	_ "github.com/mattn/go-sqlite3" // SQLite driver
+	"time"
+)
+
+type cache interface {
+	AddMessage(m *message) error
+	Messages(topic string, since sinceTime) ([]*message, error)
+	MessageCount(topic string) (int, error)
+	Topics() (map[string]*topic, error)
+	Prune(keep time.Duration) error
+}

server/cache_mem.go

@@ -0,0 +1,80 @@
+package server
+
+import (
+	_ "github.com/mattn/go-sqlite3" // SQLite driver
+	"sync"
+	"time"
+)
+
+type memCache struct {
+	messages map[string][]*message
+	mu       sync.Mutex
+}
+
+var _ cache = (*memCache)(nil)
+
+func newMemCache() *memCache {
+	return &memCache{
+		messages: make(map[string][]*message),
+	}
+}
+
+func (s *memCache) AddMessage(m *message) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if _, ok := s.messages[m.Topic]; !ok {
+		s.messages[m.Topic] = make([]*message, 0)
+	}
+	s.messages[m.Topic] = append(s.messages[m.Topic], m)
+	return nil
+}
+
+func (s *memCache) Messages(topic string, since sinceTime) ([]*message, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if _, ok := s.messages[topic]; !ok {
+		return make([]*message, 0), nil
+	}
+	messages := make([]*message, 0) // copy!
+	for _, m := range s.messages[topic] {
+		msgTime := time.Unix(m.Time, 0)
+		if msgTime == since.Time() || msgTime.After(since.Time()) {
+			messages = append(messages, m)
+		}
+	}
+	return messages, nil
+}
+
+func (s *memCache) MessageCount(topic string) (int, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if _, ok := s.messages[topic]; !ok {
+		return 0, nil
+	}
+	return len(s.messages[topic]), nil
+}
+
+func (s *memCache) Topics() (map[string]*topic, error) {
+	// Hack since we know when this is called there are no messages!
+	return make(map[string]*topic), nil
+}
+
+func (s *memCache) Prune(keep time.Duration) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for topic, _ := range s.messages {
+		s.pruneTopic(topic, keep)
+	}
+	return nil
+}
+
+func (s *memCache) pruneTopic(topic string, keep time.Duration) {
+	for i, m := range s.messages[topic] {
+		msgTime := time.Unix(m.Time, 0)
+		if time.Since(msgTime) < keep {
+			s.messages[topic] = s.messages[topic][i:]
+			return
+		}
+	}
+	s.messages[topic] = make([]*message, 0) // all messages expired
+}

server/cache_sqlite.go

@@ -0,0 +1,130 @@
+package server
+
+import (
+	"database/sql"
+	"errors"
+	_ "github.com/mattn/go-sqlite3" // SQLite driver
+	"time"
+)
+
+const (
+	createTableQuery = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS messages (
+			id VARCHAR(20) PRIMARY KEY,
+			time INT NOT NULL,
+			topic VARCHAR(64) NOT NULL,
+			message VARCHAR(1024) NOT NULL
+		);
+		CREATE INDEX IF NOT EXISTS idx_topic ON messages (topic);
+		COMMIT;
+	`
+	insertMessageQuery           = `INSERT INTO messages (id, time, topic, message) VALUES (?, ?, ?, ?)`
+	pruneMessagesQuery           = `DELETE FROM messages WHERE time < ?`
+	selectMessagesSinceTimeQuery = `
+		SELECT id, time, message 
+		FROM messages 
+		WHERE topic = ? AND time >= ?
+		ORDER BY time ASC
+	`
+	selectMessageCountQuery = `SELECT count(*) FROM messages WHERE topic = ?`
+	selectTopicsQuery       = `SELECT topic, MAX(time) FROM messages GROUP BY TOPIC`
+)
+
+type sqliteCache struct {
+	db *sql.DB
+}
+
+var _ cache = (*sqliteCache)(nil)
+
+func newSqliteCache(filename string) (*sqliteCache, error) {
+	db, err := sql.Open("sqlite3", filename)
+	if err != nil {
+		return nil, err
+	}
+	if _, err := db.Exec(createTableQuery); err != nil {
+		return nil, err
+	}
+	return &sqliteCache{
+		db: db,
+	}, nil
+}
+
+func (c *sqliteCache) AddMessage(m *message) error {
+	_, err := c.db.Exec(insertMessageQuery, m.ID, m.Time, m.Topic, m.Message)
+	return err
+}
+
+func (c *sqliteCache) Messages(topic string, since sinceTime) ([]*message, error) {
+	rows, err := c.db.Query(selectMessagesSinceTimeQuery, topic, since.Time().Unix())
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	messages := make([]*message, 0)
+	for rows.Next() {
+		var timestamp int64
+		var id, msg string
+		if err := rows.Scan(&id, &timestamp, &msg); err != nil {
+			return nil, err
+		}
+		if msg == "" {
+			msg = " " // Hack: never return empty messages; this should not happen
+		}
+		messages = append(messages, &message{
+			ID:      id,
+			Time:    timestamp,
+			Event:   messageEvent,
+			Topic:   topic,
+			Message: msg,
+		})
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return messages, nil
+}
+
+func (c *sqliteCache) MessageCount(topic string) (int, error) {
+	rows, err := c.db.Query(selectMessageCountQuery, topic)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+	var count int
+	if !rows.Next() {
+		return 0, errors.New("no rows found")
+	}
+	if err := rows.Scan(&count); err != nil {
+		return 0, err
+	} else if err := rows.Err(); err != nil {
+		return 0, err
+	}
+	return count, nil
+}
+
+func (s *sqliteCache) Topics() (map[string]*topic, error) {
+	rows, err := s.db.Query(selectTopicsQuery)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	topics := make(map[string]*topic, 0)
+	for rows.Next() {
+		var id string
+		var last int64
+		if err := rows.Scan(&id, &last); err != nil {
+			return nil, err
+		}
+		topics[id] = newTopic(id, time.Unix(last, 0))
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return topics, nil
+}
+
+func (c *sqliteCache) Prune(keep time.Duration) error {
+	_, err := c.db.Exec(pruneMessagesQuery, time.Now().Add(-1*keep).Unix())
+	return err
+}

server/example.html

@@ -0,0 +1,56 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>ntfy.sh: EventSource Example</title>
+    <meta name="robots" content="noindex, nofollow" />
+    <style>
+        body { font-size: 1.2em; line-height: 130%; }
+        #events { font-family: monospace; }
+    </style>
+</head>
+<body>
+<h1>ntfy.sh: EventSource Example</h1>
+<p>
+    This is an example showing how to use <a href="https://ntfy.sh">ntfy.sh</a> with
+    <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a>.<br/>
+    This example doesn't need a server. You can just save the HTML page and run it from anywhere.
+</p>
+<button id="publishButton">Send test notification</button>
+<p><b>Log:</b></p>
+<div id="events"></div>
+
+<script type="text/javascript">
+    const publishURL = `https://ntfy.sh/example`;
+    const subscribeURL = `https://ntfy.sh/example/sse`;
+    const events = document.getElementById('events');
+    const eventSource = new EventSource(subscribeURL);
+
+    // Publish button
+    document.getElementById("publishButton").onclick = () => {
+        fetch(publishURL, {
+            method: 'POST', // works with PUT as well, though that sends an OPTIONS request too!
+            body: `It is ${new Date().toString()}. This is a test.`
+        })
+    };
+
+    // Incoming events
+    eventSource.onopen = () => {
+        let event = document.createElement('div');
+        event.innerHTML = `EventSource connected to ${subscribeURL}`;
+        events.appendChild(event);
+    };
+    eventSource.onerror = (e) => {
+        let event = document.createElement('div');
+        event.innerHTML = `EventSource error: Failed to connect to ${subscribeURL}`;
+        events.appendChild(event);
+    };
+    eventSource.onmessage = (e) => {
+        let event = document.createElement('div');
+        event.innerHTML = e.data;
+        events.appendChild(event);
+    };
+</script>
+
+</body>
+</html>

server/index.gohtml

@@ -0,0 +1,353 @@
+{{- /*gotype: heckel.io/ntfy/server.indexPage*/ -}}
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+
+    <title>ntfy.sh | simple HTTP-based pub-sub</title>
+    <link rel="stylesheet" href="static/css/app.css" type="text/css">
+
+    <!-- Mobile view -->
+    <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=no">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
+    <meta name="HandheldFriendly" content="true">
+
+    <!-- Mobile browsers, background color -->
+    <meta name="theme-color" content="#317f6f">
+    <meta name="msapplication-navbutton-color" content="#317f6f">
+    <meta name="apple-mobile-web-app-status-bar-style" content="#317f6f">
+
+    <!-- Favicon, see favicon.io -->
+    <link rel="icon" type="image/png" href="static/img/favicon.png">
+
+    <!-- Previews in Google, Slack, WhatsApp, etc. -->
+    <meta property="og:type" content="website" />
+    <meta property="og:locale" content="en_US" />
+    <meta property="og:site_name" content="ntfy.sh" />
+    <meta property="og:title" content="ntfy.sh | simple HTTP-based pub-sub" />
+    <meta property="og:description" content="ntfy is a simple HTTP-based pub-sub notification service. It allows you to send desktop notifications via scripts from any computer, entirely without signup or cost. Made with ❤ by Philipp C. Heckel, Apache License 2.0, source at https://heckel.io/ntfy." />
+    <meta property="og:image" content="/static/img/ntfy.png" />
+    <meta property="og:url" content="https://ntfy.sh" />
+{{if .Topic}}
+    <!-- Never index topic page -->
+    <meta name="robots" content="noindex, nofollow" />
+{{end}}
+</head>
+<body>
+<div id="main"{{if .Topic}} style="display: none"{{end}}>
+    <h1><img src="static/img/ntfy.png" alt="ntfy"/><br/>ntfy.sh | simple HTTP-based pub-sub</h1>
+    <p>
+        <b>Ntfy</b> (pronounce: <i>notify</i>) is a simple HTTP-based <a href="https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern">pub-sub</a> notification service.
+        It allows you to send notifications <a href="#subscribe-phone">to your phone</a> or desktop via scripts from any computer,
+        entirely <b>without signup or cost</b>. It's also <a href="https://github.com/binwiederhier/ntfy">open source</a> if you want to run your own.
+    </p>
+
+    <div id="screenshots">
+        <a href="static/img/screenshot-curl.png"><img src="static/img/screenshot-curl.png"/></a>
+        <a href="static/img/screenshot-web-detail.png"><img src="static/img/screenshot-web-detail.png"/></a>
+        <span class="nowrap">
+            <a href="static/img/screenshot-phone-main.jpg"><img src="static/img/screenshot-phone-main.jpg"/></a>
+            <a href="static/img/screenshot-phone-detail.jpg"><img src="static/img/screenshot-phone-detail.jpg"/></a>
+            <a href="static/img/screenshot-phone-notification.jpg"><img src="static/img/screenshot-phone-notification.jpg"/></a>
+        </span>
+    </div>
+
+    <p>
+        There are many ways to use Ntfy. You can send yourself messages for all sorts of things: When a long process finishes or fails,
+        or to notify yourself when somebody logs into your server(s). Or you may want to use it in your own app to distribute messages to subscribed clients.
+        Endless possibilities 😀. Be sure to check out the <a href="#examples">examples below</a>.
+    </p>
+
+    <h2 id="publish" class="anchor">Publishing messages</h2>
+    <p>
+        Publishing messages can be done via PUT or POST. Topics are created on the fly by subscribing or publishing to them.
+        Because there is no sign-up, <b>the topic is essentially a password</b>, so pick something that's not easily guessable.
+    </p>
+    <p class="smallMarginBottom">
+        Here's an example showing how to publish a message using <tt>curl</tt> (via POST):
+    </p>
+    <code>
+        curl -d "Backup successful 😀" ntfy.sh/mytopic
+    </code>
+    <p class="smallMarginBottom">
+        And another one using PUT:
+    </p>
+    <code>
+        echo -en "\u26A0\uFE0F Unauthorized login" | curl -sT- ntfy.sh/mytopic
+    </code>
+    <p class="smallMarginBottom">
+        Here's an example in JS with <tt>fetch()</tt> (see <a href="https://github.com/binwiederhier/ntfy/tree/main/examples">full example</a>):
+    </p>
+    <code>
+        fetch('https://ntfy.sh/mytopic', {<br/>
+        &nbsp;&nbsp;method: 'POST', // PUT works too<br/>
+        &nbsp;&nbsp;body: 'Hello from the other side.'<br/>
+        })
+    </code>
+
+    <h2 id="subscribe" class="anchor">Subscribe to a topic</h2>
+    <p>
+        You can create and subscribe to a topic either in this web UI, or in your own app by subscribing to an
+        <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a>, a JSON feed, or raw feed.
+    </p>
+
+    <div id="subscribeBox">
+        <h3 id="subscribe-web" class="anchor">Subscribe in this Web UI</h3>
+        <p id="error"></p>
+        <p>
+            Subscribe to topics here and receive messages as <b>desktop notification</b>. Topics are not password-protected,
+            so choose a name that's not easy to guess. Once subscribed, you can publish messages via PUT/POST.
+        </p>
+        <form id="subscribeForm">
+            <p>
+                <b>Topic:</b><br/>
+                <input type="text" id="topicField" autocomplete="off" placeholder="Topic name, e.g. phil_alerts" maxlength="64" pattern="[-_A-Za-z0-9]{1,64}" />
+                <button id="subscribeButton">Subscribe</button>
+            </p>
+            <p id="topicsHeader"><b>Subscribed topics:</b></p>
+            <ul id="topicsList"></ul>
+        </form>
+        <audio id="notifySound" src="static/sound/mixkit-message-pop-alert-2354.mp3"></audio>
+    </div>
+
+    <h3 id="subscribe-phone" class="anchor">Subscribe from your phone</h3>
+    <p>
+        You can use the <a href="https://play.google.com/store/apps/details?id=io.heckel.ntfy">Ntfy Android App</a>
+        to receive notifications directly on your phone. Just like the server, this app is also <a href="https://github.com/binwiederhier/ntfy-android">open source</a>.
+        Since I don't have an iPhone or a Mac, I didn't make an iOS app yet. I'd be awesome if <a href="https://github.com/binwiederhier/ntfy/issues/4">someone else could help out</a>.
+    </p>
+    <p>
+        <a href="https://play.google.com/store/apps/details?id=io.heckel.ntfy"><img src="static/img/badge-googleplay.png"></a>
+        <a href="https://github.com/binwiederhier/ntfy/issues/4"><img src="static/img/badge-appstore.png"></a>
+    </p>
+
+    <h3 id="subscribe-api" class="anchor">Subscribe via your app, or via the CLI</h3>
+    <p class="smallMarginBottom">
+        Using <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a> in JS, you can consume
+        notifications like this (see <a href="example.html">live example</a>):
+    </p>
+    <code>
+        const eventSource = new EventSource('https://ntfy.sh/mytopic/sse');<br/>
+        eventSource.onmessage = (e) => {<br/>
+        &nbsp;&nbsp;// Do something with e.data<br/>
+        };
+    </code>
+    <p class="smallMarginBottom">
+        You can also use the same <tt>/sse</tt> endpoint via <tt>curl</tt> or any other HTTP library:
+    </p>
+    <code>
+        $ curl -s ntfy.sh/mytopic/sse<br/>
+        event: open<br/>
+        data: {"id":"weSj9RtNkj","time":1635528898,"event":"open","topic":"mytopic"}<br/><br/>
+
+        data: {"id":"p0M5y6gcCY","time":1635528909,"event":"message","topic":"mytopic","message":"Hi!"}<br/><br/>
+
+        event: keepalive<br/>
+        data: {"id":"VNxNIg5fpt","time":1635528928,"event":"keepalive","topic":"test"}
+    </code>
+    <p class="smallMarginBottom">
+        To consume JSON instead, use the <tt>/json</tt> endpoint, which prints one message per line:
+    </p>
+    <code>
+        $ curl -s ntfy.sh/mytopic/json<br/>
+        {"id":"SLiKI64DOt","time":1635528757,"event":"open","topic":"mytopic"}<br/>
+        {"id":"hwQ2YpKdmg","time":1635528741,"event":"message","topic":"mytopic","message":"Hi!"}<br/>
+        {"id":"DGUDShMCsc","time":1635528787,"event":"keepalive","topic":"mytopic"}
+    </code>
+    <p class="smallMarginBottom">
+        Or use the <tt>/raw</tt> endpoint if you need something super simple (empty lines are keepalive messages):
+    </p>
+    <code>
+        $ curl -s ntfy.sh/mytopic/raw<br/>
+        <br/>
+        This is a notification<br/>
+        And another one with a smiley face 😀
+    </code>
+
+    <h2 id="other-features" class="anchor">Other features</h2>
+    <h3 id="fetching-cached-messages" class="anchor">Fetching cached messages (<tt>since=</tt>)</h3>
+    <p class="smallMarginBottom">
+        Messages are cached on disk for {{.CacheDuration}} to account for network interruptions of subscribers.
+        You can read back what you missed by using the <tt>since=</tt> query parameter. It takes either a
+        duration (e.g. <tt>10m</tt> or <tt>30s</tt>), a Unix timestamp (e.g. <tt>1635528757</tt>) or <tt>all</tt> (all
+        cached messages).
+    </p>
+    <code>
+        curl -s "ntfy.sh/mytopic/json?since=10m"
+    </code>
+
+    <h3 id="polling" class="anchor">Polling (<tt>poll=1</tt>)</h3>
+    <p class="smallMarginBottom">
+        You can also just poll for messages if you don't like the long-standing connection using the <tt>poll=1</tt>
+        query parameter. The connection will end after all available messages have been read. This parameter can be
+        combined with <tt>since=</tt> (defaults to <tt>since=all</tt>).
+    </p>
+    <code>
+        curl -s "ntfy.sh/mytopic/json?poll=1"
+    </code>
+
+    <h3 id="multiple-topics" class="anchor">Subscribing to multiple topics (<tt>topic1,topic2,...</tt>)</h3>
+    <p class="smallMarginBottom">
+        It's possible to subscribe to multiple topics in one HTTP call by providing a
+        comma-separated list of topics in the URL. This allows you to reduce the number of connections you have to maintain:
+    </p>
+    <code>
+        $ curl -s ntfy.sh/mytopic1,mytopic2/json<br/>
+        {"id":"0OkXIryH3H","time":1637182619,"event":"open","topic":"mytopic1,mytopic2,mytopic3"}<br/>
+        {"id":"dzJJm7BCWs","time":1637182634,"event":"message","topic":"mytopic1","message":"for topic 1"}<br/>
+        {"id":"Cm02DsxUHb","time":1637182643,"event":"message","topic":"mytopic2","message":"for topic 2"}
+    </code>
+
+    <h2 id="examples" class="anchor">Examples</h2>
+    <p>
+        There are a million ways to use Ntfy, but here are some inspirations. I try to collect
+        <a href="https://github.com/binwiederhier/ntfy/tree/main/examples">examples on GitHub</a>, so be sure to check
+        those out, too.
+    </p>
+
+    <h3 id="example-alerts" class="anchor">Example: A long process is done: backups, copying data, pipelines, ...</h3>
+    <p class="smallMarginBottom">
+        I started adding notifications pretty much all of my scripts. Typically, I just chain the <tt>curl</tt> call
+        directly to the command I'm running. The following example will either send <i>Laptop backup succeeded</i>
+        or ⚠️ <i>Laptop backup failed</i> directly to my phone:
+    </p>
+    <code>
+        rsync -a root@laptop /backups/laptop \<br/>
+        &nbsp;&nbsp;&& zfs snapshot ... \<br/>
+        &nbsp;&nbsp;&& curl -d "Laptop backup succeeded" ntfy.sh/backups \<br/>
+        &nbsp;&nbsp;|| echo -en "\u26A0\uFE0F Laptop backup failed" | curl -sT- ntfy.sh/backups
+    </code>
+
+    <h3 id="example-web" class="anchor">Example: Server-sent messages in your web app</h3>
+    <p>
+        Just as you can <a href="#subscribe-web">subscribe to topics in this Web UI</a>, you can use Ntfy in your own
+        web application. Check out the <a href="example.html">live example</a> or just look the source of this page.
+    </p>
+
+    <h3 id="example-notify-ssh" class="anchor">Example: Notify on SSH login</h3>
+    <p>
+        Years ago my home server was broken into. That shook me hard, so every time someone logs into any machine that I
+        own, I now message myself. Here's an example of how to use <a href="https://en.wikipedia.org/wiki/Linux_PAM">PAM</a>
+        to notify yourself on SSH login.
+    </p>
+    <p class="smallMarginBottom">
+        <b>/etc/pam.d/sshd</b> (at the end of the file):
+    </p>
+    <code>
+        session optional pam_exec.so /usr/local/bin/ntfy-ssh-login.sh
+    </code>
+    <p class="smallMarginBottom">
+        <b>/usr/local/bin/ntfy-ssh-login.sh</b>:
+    </p>
+    <code>
+        #!/bin/bash<br/>
+        if [ "${PAM_TYPE}" = "open_session" ]; then<br/>
+        &nbsp;&nbsp;echo -en "\u26A0\uFE0F SSH login: ${PAM_USER} from ${PAM_RHOST}" | curl -T- ntfy.sh/alerts<br/>
+        fi
+    </code>
+
+    <h3 id="example-collect-data" class="anchor">Example: Collect data from multiple machines</h3>
+    <p>
+        The other day I was running tasks on 20 servers and I wanted to collect the interim results
+        as a CSV in one place. Here's the script I wrote:
+    </p>
+    <code>
+        while read result; do<br/>
+        &nbsp;&nbsp;[ -n "$result" ] && echo "result" >> results.csv<br/>
+        done < <(stdbuf -i0 -o0 curl -s ntfy.sh/results/raw)
+    </code>
+
+    <h2 id="faq" class="anchor">FAQ</h2>
+    <p>
+        <b id="isnt-this-like" class="anchor">Isn't this like ...?</b><br/>
+        Who knows. I didn't do a lot of research before making this. It was fun making it.
+    </p>
+
+    <p>
+        <b id="is-it-free" class="anchor">Can I use this in my app? Will it stay free?</b><br/>
+        Yes. As long as you don't abuse it, it'll be available and free of charge. I do not plan on monetizing
+        the service.
+    </p>
+
+    <p>
+        <b id="uptime-guarantees" class="anchor">What are the uptime guarantees?</b><br/>
+        Best effort.
+    </p>
+
+    <p>
+        <b id="multiple-subscribers" class="anchor">What happens if there are multiple subscribers to the same topic?</b><br/>
+        As per usual with pub-sub, all subscribers receive notifications if they are
+        subscribed to a topic.
+    </p>
+
+    <p>
+        <b id="can-you-spy-on-me" class="anchor">Will you know what topics exist, can you spy on me?</b><br/>
+        If you don't trust me or your messages are sensitive, run your own server. It's <a href="https://github.com/binwiederhier/ntfy">open source</a>.
+        That said, the logs do not contain any topic names or other details about you.
+        Messages are cached for {{.CacheDuration}} to facilitate service restarts, message polling and to overcome
+        client network disruptions.
+    </p>
+
+    <p>
+        <b id="selfhosted" class="anchor">Can I self-host it?</b><br/>
+        Yes. The server (including this Web UI) can be self-hosted, and the Android app supports adding topics from
+        your own server as well. There are <a href="https://github.com/binwiederhier/ntfy#installation">install instructions</a>
+        on GitHub.
+    </p>
+
+    <p>
+        <b id="why-firebase" class="anchor">Why is Firebase used?</b><br/>
+        In addition to caching messages locally and delivering them to long-polling subscribers, all messages are also
+        published to Firebase Cloud Messaging (FCM) (if <tt>FirebaseKeyFile</tt> is set, which it is on ntfy.sh). This
+        is to facilitate instant notifications on Android.
+    </p>
+
+    <p>
+        <b id="why-no-ios" class="anchor">Why is there no iOS app (yet)?</b><br/>
+        I don't have an iPhone or a Mac, so I didn't make an iOS app yet. I'd be awesome if
+        <a href="https://github.com/binwiederhier/ntfy/issues/4">someone else could help out</a>.
+    </p>
+
+    <h2 id="privacy" class="anchor">Privacy policy</h2>
+    <p>
+        Neither the server nor the app record any personal information, or share any of the messages and topics with
+        any outside service. All data is exclusively used to make the service function properly. The one exception
+        is the Firebase Cloud Messaging (FCM) service, which is required to provide instant Android notifications (see
+        FAQ for details).
+    </p>
+    <p>
+        The web server does not log or otherwise store request paths, remote IP addresses or even topics or messages,
+        aside from a short on-disk cache (for {{.CacheDuration}}) to support service restarts.
+    </p>
+
+    <center id="ironicCenterTagDontFreakOut"><i>Made with ❤️ by <a href="https://heckel.io">Philipp C. Heckel</a></i></center>
+</div>
+<div id="detail"{{if not .Topic}} style="display: none"{{end}}>
+    <div id="detailMain">
+        <button id="detailCloseButton"><img src="static/img/close_black_24dp.svg"/></button>
+        <h1><img src="static/img/ntfy.png" alt="ntfy"/><br/><span id="detailTitle"></span></h1>
+        <p class="smallMarginBottom">
+            <b>Ntfy</b> is a simple HTTP-based pub-sub notification service. This is a Ntfy topic.
+            To send notifications to it, simply PUT or POST to the topic URL. Here's an example using <tt>curl</tt>:
+        </p>
+        <code>
+            curl -d "Backup failed" <span id="detailTopicUrl"></span>
+        </code>
+        <p id="detailNotificationsDisallowed">
+            If you'd like to receive desktop notifications when new messages arrive on this topic, you have
+            <a href="#" onclick="return requestPermission()">grant the browser permission</a> to show notifications.
+            Click the link to do so.
+        </p>
+        <p class="smallMarginBottom">
+            <b>Recent notifications</b> (cached for {{.CacheDuration}}):
+        </p>
+        <p id="detailNoNotifications">
+            <i>You haven't received any notifications for this topic yet.</i>
+        </p>
+        <div id="detailEventsList"></div>
+    </div>
+</div>
+<div id="lightbox" class="lightbox"></div>
+<script src="static/js/app.js"></script>
+</body>
+</html>

server/index.html

@@ -1,201 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-<head>
-    <meta charset="UTF-8">
-
-    <title>ntfy.sh | simple HTTP-based pub-sub</title>
-    <link rel="stylesheet" href="static/css/app.css" type="text/css">
-
-    <!-- Mobile view -->
-    <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=no">
-    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
-    <meta name="HandheldFriendly" content="true">
-
-    <!-- Mobile browsers, background color -->
-    <meta name="theme-color" content="#39005a">
-    <meta name="msapplication-navbutton-color" content="#39005a">
-    <meta name="apple-mobile-web-app-status-bar-style" content="#39005a">
-
-    <!-- Favicon, see favicon.io -->
-    <link rel="icon" type="image/png" href="static/img/favicon.png">
-
-    <!-- Previews in Google, Slack, WhatsApp, etc. -->
-    <meta property="og:type" content="website" />
-    <meta property="og:locale" content="en_US" />
-    <meta property="og:site_name" content="ntfy.sh" />
-    <meta property="og:title" content="ntfy.sh | simple HTTP-based pub-sub" />
-    <meta property="og:description" content="ntfy is a simple HTTP-based pub-sub notification service. It allows you to send desktop notifications via scripts from any computer, entirely without signup or cost. Made with ❤ by Philipp C. Heckel, Apache License 2.0, source at https://heckel.io/ntfy." />
-    <meta property="og:image" content="/static/img/ntfy.png" />
-    <meta property="og:url" content="https://ntfy.sh" />
-</head>
-<body>
-<div id="main">
-    <h1><img src="static/img/ntfy.png" alt="ntfy"/><br/>ntfy.sh - simple HTTP-based pub-sub</h1>
-    <p>
-        <b>ntfy</b> (pronounce: <i>notify</i>) is a simple HTTP-based <a href="https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern">pub-sub</a> notification service.
-        It allows you to send <b>desktop notifications via scripts from any computer</b>, entirely <b>without signup or cost</b>.
-        It's also <a href="https://github.com/binwiederhier/ntfy">open source</a> if you want to run your own.
-    </p>
-    <p id="error"></p>
-
-    <h2>Publishing messages</h2>
-    <p>
-        Publishing messages can be done via PUT or POST using. Topics are created on the fly by subscribing or publishing to them.
-        Because there is no sign-up, <b>the topic is essentially a password</b>, so pick something that's not easily guessable.
-    </p>
-    <p class="smallMarginBottom">
-        Here's an example showing how to publish a message using <tt>curl</tt>:
-    </p>
-    <code>
-        curl -d "long process is done" ntfy.sh/mytopic
-    </code>
-    <p class="smallMarginBottom">
-        Here's an example in JS with <tt>fetch()</tt> (see <a href="https://github.com/binwiederhier/ntfy/tree/main/examples">full example</a>):
-    </p>
-    <code>
-        fetch('https://ntfy.sh/mytopic', {<br/>
-        &nbsp;&nbsp;method: 'POST', // PUT works too<br/>
-        &nbsp;&nbsp;body: 'Hello from the other side.'<br/>
-        })
-    </code>
-
-    <h2>Subscribe to a topic</h2>
-    <p>
-        You can create and subscribe to a topic either in this web UI, or in your own app by subscribing to an
-        <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a>, a JSON feed, or raw feed.
-    </p>
-
-    <h3>Subscribe via web</h3>
-    <p>
-        If you subscribe to a topic via this web UI in the field below, messages published to any subscribed topic
-        will show up as <b>desktop notification</b>.
-    </p>
-    <form id="subscribeForm">
-        <p>
-            <label for="topicField">Subscribe to topic:</label>
-            <input type="text" id="topicField" placeholder="Letters, numbers, _ and -"  pattern="[-_A-Za-z]{1,64}" />
-            <input type="submit" id="subscribeButton" value="Subscribe" />
-        </p>
-    </form>
-    <p id="topicsHeader">Topics:</p>
-    <ul id="topicsList"></ul>
-    <audio id="notifySound" src="static/sound/mixkit-message-pop-alert-2354.mp3"></audio>
-
-    <h3>Subscribe via phone</h3>
-    <p>
-        Once it's approved, you can use the <b>Ntfy Android App</b> to receive notifications directly on your phone. Just like
-        the server, this app is also <a href="https://github.com/binwiederhier/ntfy-android">open source</a>.
-    </p>
-
-    <h3>Subscribe via your app, or via the CLI</h3>
-    <p class="smallMarginBottom">
-        Using <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a> in JS, you can consume
-        notifications like this (see <a href="https://github.com/binwiederhier/ntfy/tree/main/examples">full example</a>):
-    </p>
-    <code>
-        const eventSource = new EventSource('https://ntfy.sh/mytopic/sse');<br/>
-        eventSource.onmessage = (e) => {<br/>
-        &nbsp;&nbsp;// Do something with e.data<br/>
-        };
-    </code>
-    <p class="smallMarginBottom">
-        You can also use the same <tt>/sse</tt> endpoint via <tt>curl</tt> or any other HTTP library:
-    </p>
-    <code>
-        $ curl -s ntfy.sh/mytopic/sse<br/>
-        event: open<br/>
-        data: {"id":"weSj9RtNkj","time":1635528898,"event":"open","topic":"mytopic"}<br/><br/>
-
-        data: {"id":"p0M5y6gcCY","time":1635528909,"event":"message","topic":"mytopic","message":"Hi!"}<br/><br/>
-
-        event: keepalive<br/>
-        data: {"id":"VNxNIg5fpt","time":1635528928,"event":"keepalive","topic":"test"}
-    </code>
-    <p class="smallMarginBottom">
-        To consume JSON instead, use the <tt>/json</tt> endpoint, which prints one message per line:
-    </p>
-    <code>
-        $ curl -s ntfy.sh/mytopic/json<br/>
-        {"id":"SLiKI64DOt","time":1635528757,"event":"open","topic":"mytopic"}<br/>
-        {"id":"hwQ2YpKdmg","time":1635528741,"event":"message","topic":"mytopic","message":"Hi!"}<br/>
-        {"id":"DGUDShMCsc","time":1635528787,"event":"keepalive","topic":"mytopic"}
-    </code>
-    <p class="smallMarginBottom">
-        Or use the <tt>/raw</tt> endpoint if you need something super simple (empty lines are keepalive messages):
-    </p>
-    <code>
-        $ curl -s ntfy.sh/mytopic/raw<br/>
-        <br/>
-        This is a notification
-    </code>
-
-    <h3>Message buffering and polling</h3>
-    <p class="smallMarginBottom">
-        Messages are buffered in memory for a few hours to account for network interruptions of subscribers.
-        You can read back what you missed by using the <tt>since=...</tt> query parameter. It takes either a
-        duration (e.g. <tt>10m</tt> or <tt>30s</tt>) or a Unix timestamp (e.g. <tt>1635528757</tt>):
-    </p>
-    <code>
-        $ curl -s "ntfy.sh/mytopic/json?since=10m"<br/>
-        # Same output as above, but includes messages from up to 10 minutes ago
-    </code>
-    <p class="smallMarginBottom">
-        You can also just poll for messages if you don't like the long-standing connection using the <tt>poll=1</tt>
-        query parameter. The connection will end after all available messages have been read. This parameter has to be
-        combined with <tt>since=</tt>.
-    </p>
-    <code>
-        $ curl -s "ntfy.sh/mytopic/json?poll=1&since=10m"<br/>
-        # Returns messages from up to 10 minutes ago and ends the connection
-    </code>
-
-    <h2>FAQ</h2>
-    <p>
-        <b>Isn't this like ...?</b><br/>
-        Who knows. I didn't do a lot of research before making this. It was fun making it.
-    </p>
-
-    <p>
-        <b>Can I use this in my app? Will it stay free?</b><br/>
-        Yes. As long as you don't abuse it, it'll be available and free of charge. I do not plan on monetizing
-        the service.
-    </p>
-
-    <p>
-        <b>What are the uptime guarantees?</b><br/>
-        Best effort.
-    </p>
-
-    <p>
-        <b>Will you know what topics exist, can you spy on me?</b><br/>
-        If you don't trust me or your messages are sensitive, run your own server. It's <a href="https://github.com/binwiederhier/ntfy">open source</a>.
-        That said, the logs do not contain any topic names or other details about you. Check the code if you don't believe me.
-    </p>
-
-    <p>
-        <b>Why is Firebase used?</b><br/>
-        In addition to caching messages locally and delivering them to long-polling subscribers, all messages are also
-        published to Firebase Cloud Messaging (FCM) (if <tt>FirebaseKeyFile</tt> is set, which it is on ntfy.sh). This
-        is to facilitate instant notifications on Android. I tried really, really hard to avoid using FCM, but newer
-        versions of Android made it impossible to implement <a href="https://developer.android.com/guide/background">background services</a>>.
-        I'm sorry.
-    </p>
-
-    <h2>Privacy policy</h2>
-    <p>
-        Neither the server nor the app record any personal information, or share any of the messages and topics with
-        any outside service. All data is exclusively used to make the service function properly. The notable exception
-        is the Firebase Cloud Messaging (FCM) service, which is required to provide instant Android notifications (see
-        FAQ for details).
-    </p>
-
-    <p>
-        The web server does not log or otherwise store request paths, remote IP addresses or even topics or messages,
-        aside from a short on-disk cache (up to a day) to support the <tt>since=</tt> feature and service restarts.
-    </p>
-
-    <center id="ironicCenterTagDontFreakOut"><i>Made with ❤️ by <a href="https://heckel.io">Philipp C. Heckel</a></i></center>
-</div>
-<script src="static/js/app.js"></script>
-</body>
-</html>

server/server.go

@@ -11,6 +11,8 @@ import (
 	"fmt"
 	"google.golang.org/api/option"
 	"heckel.io/ntfy/config"
+	"heckel.io/ntfy/util"
+	"html/template"
 	"io"
 	"log"
 	"net"
@@ -23,7 +25,6 @@ import (
 )
 
 // TODO add "max messages in a topic" limit
-// TODO implement persistence
 // TODO implement "since=<ID>"
 
 // Server is the main server
@@ -33,6 +34,7 @@ type Server struct {
 	visitors map[string]*visitor
 	firebase subscriber
 	messages int64
+	cache    cache
 	mu       sync.Mutex
 }
 
@@ -46,20 +48,48 @@ func (e errHTTP) Error() string {
 	return fmt.Sprintf("http: %s", e.Status)
 }
 
+type indexPage struct {
+	Topic         string
+	CacheDuration string
+}
+
+type sinceTime time.Time
+
+func (t sinceTime) IsAll() bool {
+	return t == sinceAllMessages
+}
+
+func (t sinceTime) IsNone() bool {
+	return t == sinceNoMessages
+}
+
+func (t sinceTime) Time() time.Time {
+	return time.Time(t)
+}
+
+var (
+	sinceAllMessages = sinceTime(time.Unix(0, 0))
+	sinceNoMessages  = sinceTime(time.Unix(1, 0))
+)
+
 const (
-	messageLimit = 1024
+	messageLimit = 512
 )
 
 var (
-	topicRegex = regexp.MustCompile(`^/[^/]+$`)
-	jsonRegex  = regexp.MustCompile(`^/[^/]+/json$`)
-	sseRegex   = regexp.MustCompile(`^/[^/]+/sse$`)
-	rawRegex   = regexp.MustCompile(`^/[^/]+/raw$`)
+	topicRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`) // Regex must match JS & Android app!
+	jsonRegex  = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`)
+	sseRegex   = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/sse$`)
+	rawRegex   = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/raw$`)
 
 	staticRegex = regexp.MustCompile(`^/static/.+`)
 
-	//go:embed "index.html"
-	indexSource string
+	//go:embed "index.gohtml"
+	indexSource   string
+	indexTemplate = template.Must(template.New("index").Parse(indexSource))
+
+	//go:embed "example.html"
+	exampleSource   string
 
 	//go:embed static
 	webStaticFs embed.FS
@@ -78,14 +108,35 @@ func New(conf *config.Config) (*Server, error) {
 			return nil, err
 		}
 	}
+	cache, err := createCache(conf)
+	if err != nil {
+		return nil, err
+	}
+	topics, err := cache.Topics()
+	if err != nil {
+		return nil, err
+	}
+	for _, t := range topics {
+		if firebaseSubscriber != nil {
+			t.Subscribe(firebaseSubscriber)
+		}
+	}
 	return &Server{
 		config:   conf,
+		cache:    cache,
 		firebase: firebaseSubscriber,
-		topics:   make(map[string]*topic),
+		topics:   topics,
 		visitors: make(map[string]*visitor),
 	}, nil
 }
 
+func createCache(conf *config.Config) (cache, error) {
+	if conf.CacheFile != "" {
+		return newSqliteCache(conf.CacheFile)
+	}
+	return newMemCache(), nil
+}
+
 func createFirebaseSubscriber(conf *config.Config) (subscriber, error) {
 	fb, err := firebase.NewApp(context.Background(), nil, option.WithCredentialsFile(conf.FirebaseKeyFile))
 	if err != nil {
@@ -138,30 +189,41 @@ func (s *Server) handle(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleInternal(w http.ResponseWriter, r *http.Request) error {
-	v := s.visitor(r.RemoteAddr)
-	if err := v.RequestAllowed(); err != nil {
-		return err
-	}
-	if r.Method == http.MethodGet && r.URL.Path == "/" {
+	if r.Method == http.MethodGet && (r.URL.Path == "/" || topicRegex.MatchString(r.URL.Path)) {
 		return s.handleHome(w, r)
+	} else if r.Method == http.MethodGet && r.URL.Path == "/example.html" {
+		return s.handleExample(w, r)
+	} else if r.Method == http.MethodHead && r.URL.Path == "/" {
+		return s.handleEmpty(w, r)
 	} else if r.Method == http.MethodGet && staticRegex.MatchString(r.URL.Path) {
 		return s.handleStatic(w, r)
-	} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicRegex.MatchString(r.URL.Path) {
-		return s.handlePublish(w, r, v)
-	} else if r.Method == http.MethodGet && jsonRegex.MatchString(r.URL.Path) {
-		return s.handleSubscribeJSON(w, r, v)
-	} else if r.Method == http.MethodGet && sseRegex.MatchString(r.URL.Path) {
-		return s.handleSubscribeSSE(w, r, v)
-	} else if r.Method == http.MethodGet && rawRegex.MatchString(r.URL.Path) {
-		return s.handleSubscribeRaw(w, r, v)
 	} else if r.Method == http.MethodOptions {
 		return s.handleOptions(w, r)
+	} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicRegex.MatchString(r.URL.Path) {
+		return s.withRateLimit(w, r, s.handlePublish)
+	} else if r.Method == http.MethodGet && jsonRegex.MatchString(r.URL.Path) {
+		return s.withRateLimit(w, r, s.handleSubscribeJSON)
+	} else if r.Method == http.MethodGet && sseRegex.MatchString(r.URL.Path) {
+		return s.withRateLimit(w, r, s.handleSubscribeSSE)
+	} else if r.Method == http.MethodGet && rawRegex.MatchString(r.URL.Path) {
+		return s.withRateLimit(w, r, s.handleSubscribeRaw)
 	}
 	return errHTTPNotFound
 }
 
 func (s *Server) handleHome(w http.ResponseWriter, r *http.Request) error {
-	_, err := io.WriteString(w, indexSource)
+	return indexTemplate.Execute(w, &indexPage{
+		Topic:         r.URL.Path[1:],
+		CacheDuration: util.DurationToHuman(s.config.CacheDuration),
+	})
+}
+
+func (s *Server) handleEmpty(w http.ResponseWriter, r *http.Request) error {
+	return nil
+}
+
+func (s *Server) handleExample(w http.ResponseWriter, r *http.Request) error {
+	_, err := io.WriteString(w, exampleSource)
 	return err
 }
 
@@ -171,7 +233,7 @@ func (s *Server) handleStatic(w http.ResponseWriter, r *http.Request) error {
 }
 
 func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visitor) error {
-	t, err := s.topic(r.URL.Path[1:])
+	t, err := s.topicFromID(r.URL.Path[1:])
 	if err != nil {
 		return err
 	}
@@ -180,10 +242,20 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 	if err != nil {
 		return err
 	}
-	if err := t.Publish(newDefaultMessage(t.id, string(b))); err != nil {
+	m := newDefaultMessage(t.id, string(b))
+	if m.Message == "" {
+		return errHTTPBadRequest
+	}
+	if err := t.Publish(m); err != nil {
+		return err
+	}
+	if err := s.cache.AddMessage(m); err != nil {
 		return err
 	}
 	w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
+	if err := json.NewEncoder(w).Encode(m); err != nil {
+		return err
+	}
 	s.mu.Lock()
 	s.messages++
 	s.mu.Unlock()
@@ -198,7 +270,7 @@ func (s *Server) handleSubscribeJSON(w http.ResponseWriter, r *http.Request, v *
 		}
 		return buf.String(), nil
 	}
-	return s.handleSubscribe(w, r, v, "json", "application/stream+json", encoder)
+	return s.handleSubscribe(w, r, v, "json", "application/x-ndjson", encoder)
 }
 
 func (s *Server) handleSubscribeSSE(w http.ResponseWriter, r *http.Request, v *visitor) error {
@@ -230,7 +302,9 @@ func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, v *visi
 		return errHTTPTooManyRequests
 	}
 	defer v.RemoveSubscription()
-	t, err := s.topic(strings.TrimSuffix(r.URL.Path[1:], "/"+format)) // Hack
+	topicsStr := strings.TrimSuffix(r.URL.Path[1:], "/"+format) // Hack
+	topicIDs := strings.Split(topicsStr, ",")
+	topics, err := s.topicsFromIDs(topicIDs...)
 	if err != nil {
 		return err
 	}
@@ -252,57 +326,78 @@ func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, v *visi
 		}
 		return nil
 	}
-	w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
-	w.Header().Set("Content-Type", contentType)
+	w.Header().Set("Access-Control-Allow-Origin", "*")            // CORS, allow cross-origin requests
+	w.Header().Set("Content-Type", contentType+"; charset=utf-8") // Android/Volley client needs charset!
 	if poll {
-		return sendOldMessages(t, since, sub)
+		return s.sendOldMessages(topics, since, sub)
 	}
-	subscriberID := t.Subscribe(sub)
-	defer t.Unsubscribe(subscriberID)
-	if err := sub(newOpenMessage(t.id)); err != nil { // Send out open message
+	subscriberIDs := make([]int, 0)
+	for _, t := range topics {
+		subscriberIDs = append(subscriberIDs, t.Subscribe(sub))
+	}
+	defer func() {
+		for i, subscriberID := range subscriberIDs {
+			topics[i].Unsubscribe(subscriberID) // Order!
+		}
+	}()
+	if err := sub(newOpenMessage(topicsStr)); err != nil { // Send out open message
 		return err
 	}
-	if err := sendOldMessages(t, since, sub); err != nil {
+	if err := s.sendOldMessages(topics, since, sub); err != nil {
 		return err
 	}
 	for {
 		select {
-		case <-t.ctx.Done():
-			return nil
 		case <-r.Context().Done():
 			return nil
 		case <-time.After(s.config.KeepaliveInterval):
 			v.Keepalive()
-			if err := sub(newKeepaliveMessage(t.id)); err != nil { // Send keepalive message
+			if err := sub(newKeepaliveMessage(topicsStr)); err != nil { // Send keepalive message
 				return err
 			}
 		}
 	}
 }
 
-func sendOldMessages(t *topic, since time.Time, sub subscriber) error {
-	if since.IsZero() {
+func (s *Server) sendOldMessages(topics []*topic, since sinceTime, sub subscriber) error {
+	if since.IsNone() {
 		return nil
 	}
-	for _, m := range t.Messages(since) {
-		if err := sub(m); err != nil {
+	for _, t := range topics {
+		messages, err := s.cache.Messages(t.id, since)
+		if err != nil {
 			return err
 		}
+		for _, m := range messages {
+			if err := sub(m); err != nil {
+				return err
+			}
+		}
 	}
 	return nil
 }
 
-func parseSince(r *http.Request) (time.Time, error) {
+// parseSince returns a timestamp identifying the time span from which cached messages should be received.
+//
+// Values in the "since=..." parameter can be either a unix timestamp or a duration (e.g. 12h), or
+// "all" for all messages.
+func parseSince(r *http.Request) (sinceTime, error) {
 	if !r.URL.Query().Has("since") {
-		return time.Time{}, nil
+		if r.URL.Query().Has("poll") {
+			return sinceAllMessages, nil
+		}
+		return sinceNoMessages, nil
 	}
-	if since, err := strconv.ParseInt(r.URL.Query().Get("since"), 10, 64); err == nil {
-		return time.Unix(since, 0), nil
+	if r.URL.Query().Get("since") == "all" {
+		return sinceAllMessages, nil
+	}
+	if s, err := strconv.ParseInt(r.URL.Query().Get("since"), 10, 64); err == nil {
+		return sinceTime(time.Unix(s, 0)), nil
 	}
 	if d, err := time.ParseDuration(r.URL.Query().Get("since")); err == nil {
-		return time.Now().Add(-1 * d), nil
+		return sinceTime(time.Now().Add(-1 * d)), nil
 	}
-	return time.Time{}, errHTTPBadRequest
+	return sinceNoMessages, errHTTPBadRequest
 }
 
 func (s *Server) handleOptions(w http.ResponseWriter, r *http.Request) error {
@@ -311,19 +406,31 @@ func (s *Server) handleOptions(w http.ResponseWriter, r *http.Request) error {
 	return nil
 }
 
-func (s *Server) topic(id string) (*topic, error) {
+func (s *Server) topicFromID(id string) (*topic, error) {
+	topics, err := s.topicsFromIDs(id)
+	if err != nil {
+		return nil, err
+	}
+	return topics[0], nil
+}
+
+func (s *Server) topicsFromIDs(ids... string) ([]*topic, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	if _, ok := s.topics[id]; !ok {
-		if len(s.topics) >= s.config.GlobalTopicLimit {
-			return nil, errHTTPTooManyRequests
-		}
-		s.topics[id] = newTopic(id)
-		if s.firebase != nil {
-			s.topics[id].Subscribe(s.firebase)
+	topics := make([]*topic, 0)
+	for  _, id := range ids {
+		if _, ok := s.topics[id]; !ok {
+			if len(s.topics) >= s.config.GlobalTopicLimit {
+				return nil, errHTTPTooManyRequests
+			}
+			s.topics[id] = newTopic(id, time.Now())
+			if s.firebase != nil {
+				s.topics[id].Subscribe(s.firebase)
+			}
 		}
+		topics = append(topics, s.topics[id])
 	}
-	return s.topics[id], nil
+	return topics, nil
 }
 
 func (s *Server) updateStatsAndExpire() {
@@ -337,35 +444,54 @@ func (s *Server) updateStatsAndExpire() {
 		}
 	}
 
-	// Prune old messages, remove subscriptions without subscribers
-	for _, t := range s.topics {
-		t.Prune(s.config.MessageBufferDuration)
-		subs, msgs := t.Stats()
-		if msgs == 0 && (subs == 0 || (s.firebase != nil && subs == 1)) { // Firebase is a subscriber!
-			delete(s.topics, t.id)
-		}
+	// Prune cache
+	if err := s.cache.Prune(s.config.CacheDuration); err != nil {
+		log.Printf("error pruning cache: %s", err.Error())
 	}
 
-	// Print stats
+	// Prune old messages, remove subscriptions without subscribers
 	var subscribers, messages int
 	for _, t := range s.topics {
-		subs, msgs := t.Stats()
+		subs := t.Subscribers()
+		msgs, err := s.cache.MessageCount(t.id)
+		if err != nil {
+			log.Printf("cannot get stats for topic %s: %s", t.id, err.Error())
+			continue
+		}
+		if msgs == 0 && (subs == 0 || (s.firebase != nil && subs == 1)) { // Firebase is a subscriber!
+			delete(s.topics, t.id)
+			continue
+		}
 		subscribers += subs
 		messages += msgs
 	}
+
+	// Print stats
 	log.Printf("Stats: %d message(s) published, %d topic(s) active, %d subscriber(s), %d message(s) buffered, %d visitor(s)",
 		s.messages, len(s.topics), subscribers, messages, len(s.visitors))
 }
 
+func (s *Server) withRateLimit(w http.ResponseWriter, r *http.Request, handler func(w http.ResponseWriter, r *http.Request, v *visitor) error) error {
+	v := s.visitor(r)
+	if err := v.RequestAllowed(); err != nil {
+		return err
+	}
+	return handler(w, r, v)
+}
+
 // visitor creates or retrieves a rate.Limiter for the given visitor.
 // This function was taken from https://www.alexedwards.net/blog/how-to-rate-limit-http-requests (MIT).
-func (s *Server) visitor(remoteAddr string) *visitor {
+func (s *Server) visitor(r *http.Request) *visitor {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	remoteAddr := r.RemoteAddr
 	ip, _, err := net.SplitHostPort(remoteAddr)
 	if err != nil {
 		ip = remoteAddr // This should not happen in real life; only in tests.
 	}
+	if s.config.BehindProxy && r.Header.Get("X-Forwarded-For") != "" {
+		ip = r.Header.Get("X-Forwarded-For")
+	}
 	v, exists := s.visitors[ip]
 	if !exists {
 		s.visitors[ip] = newVisitor(s.config)

server/static/css/app.css

@@ -6,6 +6,12 @@ html, body {
     font-size: 1.1em;
 }
 
+html {
+    /* prevent scrollbar from repositioning website:
+     * https://www.w3docs.com/snippets/css/how-to-prevent-scrollbar-from-repositioning-web-page.html */
+    overflow-y: scroll;
+}
+
 a, a:visited {
     color: #3a9784;
 }
@@ -22,13 +28,13 @@ h1 {
 }
 
 h2 {
-    margin-top: 20px;
+    margin-top: 30px;
     margin-bottom: 5px;
     font-size: 1.8em;
 }
 
 h3 {
-    margin-top: 20px;
+    margin-top: 25px;
     margin-bottom: 5px;
     font-size: 1.3em;
 }
@@ -58,6 +64,7 @@ code {
     border-radius: 3px;
     margin-top: 10px;
     margin-bottom: 20px;
+    overflow-x: auto;
 }
 
 /* Lato font (OFL), https://fonts.google.com/specimen/Lato#about,
@@ -87,3 +94,316 @@ code {
 #ironicCenterTagDontFreakOut {
     color: #666;
 }
+
+/* Anchors */
+
+.anchor .anchorLink {
+    color: #ccc;
+    text-decoration: none;
+    padding: 0 5px;
+    visibility: hidden;
+}
+
+.anchor:hover .anchorLink {
+    visibility: visible;
+}
+
+.anchor .anchorLink:hover {
+    color: #3a9784;
+    visibility: visible;
+}
+
+/* Screenshots */
+
+#screenshots {
+    text-align: center;
+}
+
+#screenshots img {
+    height: 190px;
+    margin: 3px;
+    border-radius: 5px;
+    filter: drop-shadow(2px 2px 2px #ddd);
+}
+
+#screenshots .nowrap {
+    white-space: nowrap;
+}
+
+/* Lightbox; thanks to https://yossiabramov.com/blog/vanilla-js-lightbox */
+
+.lightbox {
+    opacity: 0;
+    visibility: hidden;
+    position: fixed;
+    left:0;
+    right: 0;
+    top: 0;
+    bottom: 0;
+    z-index: -1;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: all 0.15s ease-in;
+}
+
+.lightbox.show {
+    background-color: rgba(0,0,0, 0.75);
+    opacity: 1;
+    visibility: visible;
+    z-index: 1000;
+}
+
+.lightbox img {
+    max-width: 90%;
+    max-height: 90%;
+    filter: drop-shadow(5px 5px 10px #222);
+    border-radius: 5px;
+}
+
+.lightbox .close-lightbox {
+    cursor: pointer;
+    position: absolute;
+    top: 30px;
+    right: 30px;
+    width: 20px;
+    height: 20px;
+}
+
+.lightbox .close-lightbox::after,
+.lightbox .close-lightbox::before {
+    content: '';
+    width: 3px;
+    height: 20px;
+    background-color: #ddd;
+    position: absolute;
+    border-radius: 5px;
+    transform: rotate(45deg);
+}
+
+.lightbox .close-lightbox::before {
+    transform: rotate(-45deg);
+}
+
+.lightbox .close-lightbox:hover::after,
+.lightbox .close-lightbox:hover::before {
+    background-color: #fff;
+}
+
+/* Subscribe box */
+
+button {
+    background: #3a9784;
+    border: none;
+    border-radius: 3px;
+    padding: 3px 5px;
+    color: white;
+    cursor: pointer;
+}
+
+button:hover {
+    background: #317f6f;
+    padding: 5px;
+}
+
+ul {
+    padding-left: 1em;
+    list-style-type: circle;
+    padding-bottom: 0;
+    margin: 0;
+}
+
+li {
+    padding: 4px 0;
+    margin: 4px 0;
+    font-size: 0.9em;
+}
+
+/* Subscribe box SMALL SCREEN */
+@media only screen and (max-width: 1599px) {
+    #subscribeBox #subscribeForm {
+        border-left: 4px solid #3a9784;
+        padding: 10px;
+    }
+
+    #subscribeBox #topicsHeader {
+        margin-bottom: 0;
+    }
+
+    #subscribeBox input {
+        height: 24px;
+        min-width: 200px;
+        max-width: 300px;
+        border-radius: 3px;
+        border: none;
+        border-bottom: 1px solid #aaa;
+        font-size: 0.8em;
+    }
+
+    #subscribeBox input:focus {
+        border-bottom: 2px solid #3a9784;
+        outline: none;
+    }
+
+    #subscribeBox ul {
+        margin: 0;
+    }
+
+    #subscribeBox li {
+        margin: 3px 0;
+        padding: 0;
+    }
+
+    #subscribeBox li img {
+        width: 15px;
+        height: 15px;
+        vertical-align: bottom;
+    }
+
+    #subscribeBox li a {
+        padding: 0 5px 0 0;
+    }
+
+    #subscribeBox button {
+        font-size: 0.8em;
+        background: #3a9784;
+        border-radius: 3px;
+        padding: 5px;
+        color: white;
+        cursor: pointer;
+    }
+
+    #subscribeBox button:hover {
+        background: #317f6f;
+    }
+}
+
+/* Subscribe box BIG SCREEN */
+@media only screen and (min-width: 1600px) {
+    #subscribeBox {
+        position: fixed;
+        top: 170px;
+        right: 10px;
+        width: 300px;
+        border-left: 4px solid #3a9784;
+        padding: 10px;
+    }
+
+    #subscribeBox h3 {
+        margin-top: 0;
+        margin-bottom: 5px;
+        font-size: 1.1em;
+    }
+
+    #subscribeBox #topicsHeader {
+        margin-bottom: 0;
+    }
+
+    #subscribeBox p {
+        font-size: 0.9em;
+        margin-bottom: 10px;
+    }
+
+    #subscribeBox ul {
+        margin: 0;
+    }
+
+    #subscribeBox input {
+        height: 18px;
+        border-radius: 3px;
+        border: none;
+        border-bottom: 1px solid #aaa;
+    }
+
+    #subscribeBox input:focus {
+        border-bottom: 2px solid #3a9784;
+        outline: none;
+    }
+
+    #subscribeBox li {
+        margin: 3px 0;
+        padding: 0;
+    }
+
+    #subscribeBox li img {
+        width: 15px;
+        height: 15px;
+        vertical-align: bottom;
+    }
+
+    #subscribeBox li a {
+        padding: 0 5px 0 0;
+    }
+
+    #subscribeBox button {
+        font-size: 0.7em;
+        background: #3a9784;
+        border-radius: 3px;
+        padding: 5px;
+        color: white;
+        cursor: pointer;
+    }
+
+    #subscribeBox button:hover {
+        background: #317f6f;
+    }
+}
+
+/** Detail view */
+#detail {
+    display: none;
+    position: absolute;
+    z-index: 1;
+    left: 8px;
+    right: 8px;
+    top: 0;
+    bottom: 0;
+    background: white;
+}
+
+#detail .detailDate {
+    color: #888;
+    font-size: 0.9em;
+}
+
+#detail .detailMessage {
+    margin-bottom: 20px;
+    font-size: 1.1em;
+}
+
+#detail #detailMain {
+    max-width: 900px;
+    margin: 0 auto;
+    position: relative; /* required for close button's "position: absolute" */
+    padding-bottom: 50px; /* Chrome and Firefox behave differently regarding bottom margin */
+}
+
+#detail #detailCloseButton {
+    background: #eee;
+    border-radius: 5px;
+    border: none;
+    padding: 5px;
+    position: absolute;
+    right: 0;
+    top: 10px;
+    display: block;
+}
+
+#detail #detailCloseButton:hover {
+    padding: 5px;
+    background: #ccc;
+}
+
+#detail #detailCloseButton img {
+    display: block; /* get rid of the weird bottom border */
+}
+
+#detail #detailNotificationsDisallowed {
+    display: none;
+    color: darkred;
+}
+
+#detail #events {
+    max-width: 900px;
+    margin: 0 auto 50px auto;
+}

server/static/img/clear_black_24dp.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 0 24 24" width="24px" fill="#FFFFFF"><path d="M0 0h24v24H0V0z" fill="none"/><path d="M19 6.41L17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41z"/></svg>

server/static/img/close_black_24dp.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 0 24 24" width="24px" fill="#000000"><path d="M0 0h24v24H0V0z" fill="none"/><path d="M19 6.41L17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41z"/></svg>

server/static/img/send_black_24dp.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 0 24 24" width="24px" fill="#ffffff"><path d="M0 0h24v24H0z" fill="none"/><path d="M2.01 21L23 12 2.01 3 2 10l15 2-15 2z"/></svg>

server/static/js/app.js

@@ -10,37 +10,53 @@
 /* All the things */
 
 let topics = {};
+let currentTopic = "";
+let currentTopicUnsubscribeOnClose = false;
 
+/* Main view */
+const main = document.getElementById("main");
 const topicsHeader = document.getElementById("topicsHeader");
 const topicsList = document.getElementById("topicsList");
 const topicField = document.getElementById("topicField");
 const notifySound = document.getElementById("notifySound");
 const subscribeButton = document.getElementById("subscribeButton");
-const subscribeForm = document.getElementById("subscribeForm");
 const errorField = document.getElementById("error");
+const originalTitle = document.title;
+
+/* Detail view */
+const detailView = document.getElementById("detail");
+const detailTitle = document.getElementById("detailTitle");
+const detailEventsList = document.getElementById("detailEventsList");
+const detailTopicUrl = document.getElementById("detailTopicUrl");
+const detailNoNotifications = document.getElementById("detailNoNotifications");
+const detailCloseButton = document.getElementById("detailCloseButton");
+const detailNotificationsDisallowed = document.getElementById("detailNotificationsDisallowed");
+
+/* Screenshots */
+const lightbox = document.getElementById("lightbox");
 
 const subscribe = (topic) => {
     if (Notification.permission !== "granted") {
         Notification.requestPermission().then((permission) => {
             if (permission === "granted") {
-                subscribeInternal(topic, 0);
+                subscribeInternal(topic, true, 0);
             } else {
                 showNotificationDeniedError();
             }
         });
     } else {
-        subscribeInternal(topic, 0);
+        subscribeInternal(topic, true,0);
     }
 };
 
-const subscribeInternal = (topic, delaySec) => {
+const subscribeInternal = (topic, persist, delaySec) => {
     setTimeout(() => {
         // Render list entry
         let topicEntry = document.getElementById(`topic-${topic}`);
         if (!topicEntry) {
             topicEntry = document.createElement('li');
             topicEntry.id = `topic-${topic}`;
-            topicEntry.innerHTML = `${topic} <button onclick="test('${topic}')">Test</button> <button onclick="unsubscribe('${topic}')">Unsubscribe</button>`;
+            topicEntry.innerHTML = `<a href="/${topic}" onclick="return showDetail('${topic}')">${topic}</a> <button onclick="test('${topic}'); return false;"> <img src="static/img/send_black_24dp.svg"> Test</button> <button onclick="unsubscribe('${topic}'); return false;"> <img src="static/img/clear_black_24dp.svg"> Unsubscribe</button>`;
             topicsList.appendChild(topicEntry);
         }
         topicsHeader.style.display = '';
@@ -48,30 +64,47 @@ const subscribeInternal = (topic, delaySec) => {
         // Open event source
         let eventSource = new EventSource(`${topic}/sse`);
         eventSource.onopen = () => {
-            topicEntry.innerHTML = `${topic} <button onclick="test('${topic}')">Test</button> <button onclick="unsubscribe('${topic}')">Unsubscribe</button>`;
+            topicEntry.innerHTML = `<a href="/${topic}" onclick="return showDetail('${topic}')">${topic}</a> <button onclick="test('${topic}'); return false;"> <img src="static/img/send_black_24dp.svg"> Test</button> <button onclick="unsubscribe('${topic}'); return false;"> <img src="static/img/clear_black_24dp.svg"> Unsubscribe</button>`;
             delaySec = 0; // Reset on successful connection
         };
         eventSource.onerror = (e) => {
+            topicEntry.innerHTML = `<a href="/${topic}" onclick="return showDetail('${topic}')">${topic}</a> <i>(Reconnecting)</i> <button disabled="disabled">Test</button> <button onclick="unsubscribe('${topic}'); return false;">Unsubscribe</button>`;
+            eventSource.close();
             const newDelaySec = (delaySec + 5 <= 15) ? delaySec + 5 : 15;
-            topicEntry.innerHTML = `${topic} <i>(Reconnecting in ${newDelaySec}s ...)</i> <button disabled="disabled">Test</button> <button onclick="unsubscribe('${topic}')">Unsubscribe</button>`;
-            eventSource.close()
-            subscribeInternal(topic, newDelaySec);
+            subscribeInternal(topic, persist, newDelaySec);
         };
         eventSource.onmessage = (e) => {
             const event = JSON.parse(e.data);
-            notifySound.play();
-            new Notification(`${location.host}/${topic}`, {
-                body: event.message,
-                icon: '/static/img/favicon.png'
-            });
+            topics[topic]['messages'].push(event);
+            topics[topic]['messages'].sort((a, b) => { return a.time < b.time ? 1 : -1; }); // Newest first
+            if (currentTopic === topic) {
+                rerenderDetailView();
+            }
+            if (Notification.permission === "granted") {
+                notifySound.play();
+                new Notification(`${location.host}/${topic}`, {
+                    body: event.message,
+                    icon: '/static/img/favicon.png'
+                });
+            }
         };
-        topics[topic] = eventSource;
-        localStorage.setItem('topics', JSON.stringify(Object.keys(topics)));
+        topics[topic] = {
+            'eventSource': eventSource,
+            'messages': [],
+            'persist': persist
+        };
+        fetchCachedMessages(topic).then(() => {
+            if (currentTopic === topic) {
+                rerenderDetailView();
+            }
+        })
+        let persistedTopicKeys = Object.keys(topics).filter(t => topics[t].persist);
+        localStorage.setItem('topics', JSON.stringify(persistedTopicKeys));
     }, delaySec * 1000);
 };
 
 const unsubscribe = (topic) => {
-    topics[topic].close();
+    topics[topic]['eventSource'].close();
     delete topics[topic];
     localStorage.setItem('topics', JSON.stringify(Object.keys(topics)));
     document.getElementById(`topic-${topic}`).remove();
@@ -83,8 +116,80 @@ const unsubscribe = (topic) => {
 const test = (topic) => {
     fetch(`/${topic}`, {
         method: 'PUT',
-        body: `This is a test notification`
+        body: `This is a test notification sent by the ntfy.sh Web UI at ${new Date().toString()}.`
+    });
+};
+
+const fetchCachedMessages = async (topic) => {
+    const topicJsonUrl = `/${topic}/json?poll=1`; // Poll!
+    for await (let line of makeTextFileLineIterator(topicJsonUrl)) {
+        const message = JSON.parse(line);
+        topics[topic]['messages'].push(message);
+    }
+    topics[topic]['messages'].sort((a, b) => { return a.time < b.time ? 1 : -1; }); // Newest first
+};
+
+const showDetail = (topic) => {
+    currentTopic = topic;
+    history.replaceState(topic, `ntfy.sh/${topic}`, `/${topic}`);
+    window.scrollTo(0, 0);
+    rerenderDetailView();
+    return false;
+};
+
+const rerenderDetailView = () => {
+    detailTitle.innerHTML = `ntfy.sh/${currentTopic}`; // document.location.replaceAll(..)
+    detailTopicUrl.innerHTML = `ntfy.sh/${currentTopic}`;
+    while (detailEventsList.firstChild) {
+        detailEventsList.removeChild(detailEventsList.firstChild);
+    }
+    topics[currentTopic]['messages'].forEach(m => {
+        let dateDiv = document.createElement('div');
+        let messageDiv = document.createElement('div');
+        let eventDiv = document.createElement('div');
+        dateDiv.classList.add('detailDate');
+        dateDiv.innerHTML = new Date(m.time * 1000).toLocaleString();
+        messageDiv.classList.add('detailMessage');
+        messageDiv.innerText = m.message;
+        eventDiv.appendChild(dateDiv);
+        eventDiv.appendChild(messageDiv);
+        detailEventsList.appendChild(eventDiv);
     })
+    if (topics[currentTopic]['messages'].length === 0) {
+        detailNoNotifications.style.display = '';
+    } else {
+        detailNoNotifications.style.display = 'none';
+    }
+    if (Notification.permission === "granted") {
+        detailNotificationsDisallowed.style.display = 'none';
+    } else {
+        detailNotificationsDisallowed.style.display = 'block';
+    }
+    detailView.style.display = 'block';
+    main.style.display = 'none';
+};
+
+const hideDetailView = () => {
+    if (currentTopicUnsubscribeOnClose) {
+        unsubscribe(currentTopic);
+        currentTopicUnsubscribeOnClose = false;
+    }
+    currentTopic = "";
+    history.replaceState('', originalTitle, '/');
+    detailView.style.display = 'none';
+    main.style.display = '';
+    return false;
+};
+
+const requestPermission = () => {
+    if (Notification.permission !== "granted") {
+        Notification.requestPermission().then((permission) => {
+            if (permission === "granted") {
+                detailNotificationsDisallowed.style.display = 'none';
+            }
+        });
+    }
+    return false;
 };
 
 const showError = (msg) => {
@@ -101,7 +206,87 @@ const showNotificationDeniedError = () => {
     showError("You have blocked desktop notifications for this website. Please unblock them and refresh to use the web-based desktop notifications.");
 };
 
-subscribeForm.onsubmit = function () {
+const showScreenshotOverlay = (e, el, index) => {
+    lightbox.classList.add('show');
+    document.addEventListener('keydown', nextScreenshotKeyboardListener);
+    return showScreenshot(e, index);
+};
+
+const showScreenshot = (e, index) => {
+    const actualIndex = resolveScreenshotIndex(index);
+    lightbox.innerHTML = '<div class="close-lightbox"></div>' + screenshots[actualIndex].innerHTML;
+    lightbox.querySelector('img').onclick = (e) => { return showScreenshot(e,actualIndex+1); };
+    currentScreenshotIndex = actualIndex;
+    e.stopPropagation();
+    return false;
+};
+
+const nextScreenshot = (e) => {
+    return showScreenshot(e, currentScreenshotIndex+1);
+};
+
+const previousScreenshot = (e) => {
+    return showScreenshot(e, currentScreenshotIndex-1);
+};
+
+const resolveScreenshotIndex = (index) => {
+    if (index < 0) {
+        return screenshots.length - 1;
+    } else if (index > screenshots.length - 1) {
+        return 0;
+    }
+    return index;
+};
+
+const hideScreenshotOverlay = (e) => {
+    lightbox.classList.remove('show');
+    document.removeEventListener('keydown', nextScreenshotKeyboardListener);
+};
+
+const nextScreenshotKeyboardListener = (e) => {
+    switch (e.keyCode) {
+        case 37:
+            previousScreenshot(e);
+            break;
+        case 39:
+            nextScreenshot(e);
+            break;
+    }
+};
+
+// From: https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch
+async function* makeTextFileLineIterator(fileURL) {
+    const utf8Decoder = new TextDecoder('utf-8');
+    const response = await fetch(fileURL);
+    const reader = response.body.getReader();
+    let { value: chunk, done: readerDone } = await reader.read();
+    chunk = chunk ? utf8Decoder.decode(chunk) : '';
+
+    const re = /\n|\r|\r\n/gm;
+    let startIndex = 0;
+    let result;
+
+    for (;;) {
+        let result = re.exec(chunk);
+        if (!result) {
+            if (readerDone) {
+                break;
+            }
+            let remainder = chunk.substr(startIndex);
+            ({ value: chunk, done: readerDone } = await reader.read());
+            chunk = remainder + (chunk ? utf8Decoder.decode(chunk) : '');
+            startIndex = re.lastIndex = 0;
+            continue;
+        }
+        yield chunk.substring(startIndex, result.index);
+        startIndex = re.lastIndex;
+    }
+    if (startIndex < chunk.length) {
+        yield chunk.substr(startIndex); // last line didn't end in a newline char
+    }
+}
+
+subscribeButton.onclick = () => {
     if (!topicField.value) {
         return false;
     }
@@ -110,6 +295,18 @@ subscribeForm.onsubmit = function () {
     return false;
 };
 
+detailCloseButton.onclick = () => {
+    hideDetailView();
+};
+
+let currentScreenshotIndex = 0;
+const screenshots = [...document.querySelectorAll("#screenshots a")];
+screenshots.forEach((el, index) => {
+    el.onclick = (e) => { return showScreenshotOverlay(e, el, index); };
+});
+
+lightbox.onclick = hideScreenshotOverlay;
+
 // Disable Web UI if notifications of EventSource are not available
 if (!window["Notification"] || !window["EventSource"]) {
     showBrowserIncompatibleError();
@@ -121,13 +318,32 @@ if (!window["Notification"] || !window["EventSource"]) {
 topicField.value = "";
 
 // Restore topics
-const storedTopics = localStorage.getItem('topics');
-if (storedTopics && Notification.permission === "granted") {
-    const storedTopicsArray = JSON.parse(storedTopics)
-    storedTopicsArray.forEach((topic) => { subscribeInternal(topic, 0); });
-    if (storedTopicsArray.length === 0) {
+const storedTopics = JSON.parse(localStorage.getItem('topics') || "[]");
+if (storedTopics) {
+    storedTopics.forEach((topic) => { subscribeInternal(topic, true, 0); });
+    if (storedTopics.length === 0) {
         topicsHeader.style.display = 'none';
     }
 } else {
     topicsHeader.style.display = 'none';
 }
+
+// (Temporarily) subscribe topic if we navigated to /sometopic URL
+const match = location.pathname.match(/^\/([-_a-zA-Z0-9]{1,64})$/) // Regex must match Go & Android app!
+if (match) {
+    currentTopic = match[1];
+    if (!storedTopics.includes(currentTopic)) {
+        subscribeInternal(currentTopic, false,0);
+        currentTopicUnsubscribeOnClose = true;
+    }
+}
+
+// Add anchor links
+document.querySelectorAll('.anchor').forEach((el) => {
+    if (el.hasAttribute('id')) {
+        const id = el.getAttribute('id');
+        const anchor = document.createElement('a');
+        anchor.innerHTML = `<a href="#${id}" class="anchorLink">#</a>`;
+        el.appendChild(anchor);
+    }
+});

server/topic.go

@@ -1,7 +1,6 @@
 package server
 
 import (
-	"context"
 	"log"
 	"math/rand"
 	"sync"
@@ -12,11 +11,8 @@ import (
 // can publish a message
 type topic struct {
 	id          string
-	subscribers map[int]subscriber
-	messages    []*message
 	last        time.Time
-	ctx         context.Context
-	cancel      context.CancelFunc
+	subscribers map[int]subscriber
 	mu          sync.Mutex
 }
 
@@ -24,17 +20,15 @@ type topic struct {
 type subscriber func(msg *message) error
 
 // newTopic creates a new topic
-func newTopic(id string) *topic {
-	ctx, cancel := context.WithCancel(context.Background())
+func newTopic(id string, last time.Time) *topic {
 	return &topic{
 		id:          id,
+		last:        last,
 		subscribers: make(map[int]subscriber),
-		last:        time.Now(),
-		ctx:         ctx,
-		cancel:      cancel,
 	}
 }
 
+// Subscribe subscribes to this topic
 func (t *topic) Subscribe(s subscriber) int {
 	t.mu.Lock()
 	defer t.mu.Unlock()
@@ -44,57 +38,31 @@ func (t *topic) Subscribe(s subscriber) int {
 	return subscriberID
 }
 
+// Unsubscribe removes the subscription from the list of subscribers
 func (t *topic) Unsubscribe(id int) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	delete(t.subscribers, id)
 }
 
+// Publish asynchronously publishes to all subscribers
 func (t *topic) Publish(m *message) error {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-	t.last = time.Now()
-	t.messages = append(t.messages, m)
-	for _, s := range t.subscribers {
-		if err := s(m); err != nil {
-			log.Printf("error publishing message to subscriber")
+	go func() {
+		t.mu.Lock()
+		defer t.mu.Unlock()
+		t.last = time.Now()
+		for _, s := range t.subscribers {
+			if err := s(m); err != nil {
+				log.Printf("error publishing message to subscriber")
+			}
 		}
-	}
+	}()
 	return nil
 }
 
-func (t *topic) Messages(since time.Time) []*message {
+// Subscribers returns the number of subscribers to this topic
+func (t *topic) Subscribers() int {
 	t.mu.Lock()
 	defer t.mu.Unlock()
-	messages := make([]*message, 0) // copy!
-	for _, m := range t.messages {
-		msgTime := time.Unix(m.Time, 0)
-		if msgTime == since || msgTime.After(since) {
-			messages = append(messages, m)
-		}
-	}
-	return messages
-}
-
-func (t *topic) Prune(keep time.Duration) {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-	for i, m := range t.messages {
-		msgTime := time.Unix(m.Time, 0)
-		if time.Since(msgTime) < keep {
-			t.messages = t.messages[i:]
-			return
-		}
-	}
-	t.messages = make([]*message, 0)
-}
-
-func (t *topic) Stats() (subscribers int, messages int) {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-	return len(t.subscribers), len(t.messages)
-}
-
-func (t *topic) Close() {
-	t.cancel()
+	return len(t.subscribers)
 }

server/visitor.go

@@ -24,7 +24,7 @@ type visitor struct {
 func newVisitor(conf *config.Config) *visitor {
 	return &visitor{
 		config:        conf,
-		limiter:       rate.NewLimiter(conf.VisitorRequestLimit, conf.VisitorRequestLimitBurst),
+		limiter:       rate.NewLimiter(rate.Every(conf.VisitorRequestLimitReplenish), conf.VisitorRequestLimitBurst),
 		subscriptions: util.NewLimiter(int64(conf.VisitorSubscriptionLimit)),
 		seen:          time.Now(),
 	}

util/util.go

@@ -1,6 +1,7 @@
 package util
 
 import (
+	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -27,3 +28,35 @@ func RandomString(length int) string {
 	}
 	return string(b)
 }
+
+// DurationToHuman converts a duration to a human readable format
+func DurationToHuman(d time.Duration) (str string) {
+	if d == 0 {
+		return "0"
+	}
+
+	d = d.Round(time.Second)
+	days := d / time.Hour / 24
+	if days > 0 {
+		str += fmt.Sprintf("%dd", days)
+	}
+	d -= days * time.Hour * 24
+
+	hours := d / time.Hour
+	if hours > 0 {
+		str += fmt.Sprintf("%dh", hours)
+	}
+	d -= hours * time.Hour
+
+	minutes := d / time.Minute
+	if minutes > 0 {
+		str += fmt.Sprintf("%dm", minutes)
+	}
+	d -= minutes * time.Minute
+
+	seconds := d / time.Second
+	if seconds > 0 {
+		str += fmt.Sprintf("%ds", seconds)
+	}
+	return
+}