Fix rate limiting behind proxy, make configurable

cmd/app.go

@@ -22,8 +22,13 @@ func New() *cli.App {
 		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.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: "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.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",
@@ -50,6 +55,11 @@ func execRun(c *cli.Context) error {
 	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) {
@@ -69,6 +79,11 @@ func execRun(c *cli.Context) error {
 	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

@@ -2,7 +2,6 @@
 package config
 
 import (
-	"golang.org/x/time/rate"
 	"time"
 )
 
@@ -15,42 +14,44 @@ const (
 )
 
 // Defines all the limits
-// - request limit: max number of PUT/GET/.. requests (here: 50 requests bucket, replenished at a rate of one per 10 seconds)
 // - 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(10 * 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
-	CacheFile                string
-	CacheDuration            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:          "",
-		CacheFile:                "",
-		CacheDuration:            DefaultCacheDuration,
-		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

@@ -25,6 +25,30 @@
 #
 # 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

server/index.html

@@ -33,10 +33,14 @@
     <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>notifications to your phone or desktop 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.
+        It allows you to send notifications <a href="https://play.google.com/store/apps/details?id=io.heckel.ntfy">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>
+    <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 (a backup, a long rsync job, ...),
+        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 😀.
     </p>
-    <p id="error"></p>
 
     <h2>Publishing messages</h2>
     <p>
@@ -65,23 +69,26 @@
         <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">
+    <div id="subscribeBox">
+        <h3>Subscribe in this Web UI</h3>
+        <p id="error"></p>
         <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" />
+            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>
-    <p id="topicsHeader">Topics:</p>
-    <ul id="topicsList"></ul>
-    <audio id="notifySound" src="static/sound/mixkit-message-pop-alert-2354.mp3"></audio>
+        <form id="subscribeForm">
+            <p>
+                <b>Topic:</b><br/>
+                <input type="text" id="topicField" autocomplete="off" placeholder="Topic name, e.g. phil_alerts"  pattern="[-_A-Za-z]{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>Subscribe via phone</h3>
+    <h3>Subscribe via Android App</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>.
@@ -128,6 +135,14 @@
         <br/>
         This is a notification
     </code>
+    <p class="smallMarginBottom">
+        Here's an example of how to use this endpoint to send desktop notifications for every incoming message:
+    </p>
+    <code>
+        while read msg; do<br/>
+        &nbsp;&nbsp;[ -n "$msg" ] && notify-send "$msg"<br/>
+        done < <(stdbuf -i0 -o0 curl -s ntfy.sh/mytopic/raw)
+    </code>
 
     <h3>Message buffering and polling</h3>
     <p class="smallMarginBottom">
@@ -177,8 +192,7 @@
         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.
+        versions of Android made it impossible to implement <a href="https://developer.android.com/guide/background">background services</a>.
     </p>
 
     <h2>Privacy policy</h2>
@@ -188,7 +202,6 @@
         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 service restarts.

server/server.go

@@ -159,24 +159,22 @@ 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 == "/" {
 		return s.handleHome(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
 }
@@ -186,6 +184,10 @@ func (s *Server) handleHome(w http.ResponseWriter, r *http.Request) error {
 	return err
 }
 
+func (s *Server) handleEmpty(w http.ResponseWriter, r *http.Request) error {
+	return nil
+}
+
 func (s *Server) handleStatic(w http.ResponseWriter, r *http.Request) error {
 	http.FileServer(http.FS(webStaticFs)).ServeHTTP(w, r)
 	return nil
@@ -394,15 +396,27 @@ func (s *Server) updateStatsAndExpire() {
 		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

@@ -58,6 +58,7 @@ 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 +88,159 @@ code {
 #ironicCenterTagDontFreakOut {
     color: #666;
 }
+
+/* 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: none;
+    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;
+        padding: 0;
+    }
+
+    #subscribeBox li {
+        margin: 3px 0;
+        padding: 0;
+    }
+
+    #subscribeBox li img {
+        width: 15px;
+        height: 15px;
+        vertical-align: bottom;
+    }
+
+    #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;
+        padding: 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 button {
+        font-size: 0.7em;
+        background: #3a9784;
+        border-radius: 3px;
+        padding: 5px;
+        color: white;
+        cursor: pointer;
+    }
+
+    #subscribeBox button:hover {
+        background: #317f6f;
+    }
+
+}
+
+

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/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

@@ -16,7 +16,6 @@ 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 subscribe = (topic) => {
@@ -40,7 +39,7 @@ const subscribeInternal = (topic, delaySec) => {
         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 = `${topic} <button onclick="test('${topic}'); return false;"> <img src="static/img/send_black_24dp.svg"> Test</button> <button onclick="unsubscribe('${topic}'); return false;"> <img src="static/img/clear_black_24dp.svg"> Unsubscribe</button>`;
             topicsList.appendChild(topicEntry);
         }
         topicsHeader.style.display = '';
@@ -48,13 +47,13 @@ const subscribeInternal = (topic, delaySec) => {
         // Open event source
         let eventSource = new EventSource(`${topic}/sse`);
         eventSource.onopen = () => {
-            topicEntry.innerHTML = `${topic} <button onclick="test('${topic}')">Test</button> <button onclick="unsubscribe('${topic}')">Unsubscribe</button>`;
+            topicEntry.innerHTML = `${topic} <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 = `${topic} <i>(Reconnecting)</i> <button disabled="disabled">Test</button> <button onclick="unsubscribe('${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);
         };
         eventSource.onmessage = (e) => {
@@ -83,7 +82,7 @@ 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()}.`
     })
 };
 
@@ -101,7 +100,7 @@ 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 () {
+subscribeButton.onclick = function () {
     if (!topicField.value) {
         return false;
     }

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(),
 	}