Merge pull request #1 from nwtse/master

Add possibility to manipulate /metrics endpoint registration

spec/indexSpec.js

@@ -6,14 +6,16 @@ let express = require("express"),
     bundle = require("../");
 
 describe("index", () => {
-    it("/metrics returns up=1", done => {
+    it("metrics returns up=1", done => {
         const app = express();
-        app.use(bundle({
+        const bundled = bundle({
             prefix: "hello:",
             whitelist: ["up"]
-        }));
+        });
+        app.use(bundled);
+
         app.use("/test", (req, res) => res.send("it worked"));
-        
+
         const agent = supertest(app);
         agent.get("/test").end(() => {
             agent
@@ -25,6 +27,41 @@ describe("index", () => {
                 });
         });
     });
+
+    it("metrics should be attached to /metrics by default", done => {
+        const app = express();
+        const bundled = bundle({
+            prefix: "hello:",
+            whitelist: ["up"]
+        });
+        app.use(bundled);
+
+        const agent = supertest(app);
+        agent.get("/metrics")
+            .end((err, res) => {
+                expect(res.status).toBe(200);
+                done();
+            });
+    });
+
+    it("metrics can be attached to /metrics programatically", done => {
+        const app = express();
+        const bundled = bundle({
+            autoregister: false
+        });
+        app.use(bundled.metricsMiddleware);
+        app.use(bundled);
+
+        app.use("/test", (req, res) => res.send("it worked"));
+
+        const agent = supertest(app);
+        agent.get("/metrics")
+            .end((err, res) => {
+                expect(res.status).toBe(200);
+                done();
+            });
+    });
+
     it("metrics can be filtered using exect match", () => {
         const instance = bundle({blacklist: ["up"]});
         expect(instance.metrics.up).not.toBeDefined();
@@ -79,7 +116,7 @@ describe("index", () => {
             });
     });
     it("filters out the excludeRoutes", done => {
-       const app = express();
+        const app = express();
         const instance = bundle({
             excludeRoutes: ["/test"]
         });
@@ -100,4 +137,4 @@ describe("index", () => {
                     });
             });
     });
-});
+});

src/index.js

@@ -40,11 +40,11 @@ function prepareMetricNames(opts, metricTemplates) {
 }
 
 function main(opts) {
-    opts = opts === undefined ? {} : opts;
+    opts = Object.assign({ autoregister: true }, opts || {} );
     if (arguments[2] && arguments[1] && arguments[1].send) {
         arguments[1].status(500)
             .send("<h1>500 Error</h1>\n"
-                + "<p>Unexapected 3d param in express-prom-bundle.\n"
+                + "<p>Unexapected 3rd param in express-prom-bundle.\n"
                 + "<p>Did you just put express-prom-bundle into app.use "
                 + "without calling it as a function first?");
         return;
@@ -91,19 +91,22 @@ function main(opts) {
         metrics.up.set(1);
     }
 
-    const middleware = function (req, res, next) {
-        if (req.path == "/metrics") {
-            let memoryUsage = process.memoryUsage();
-            if (metrics["nodejs_memory_heap_total_bytes"]) {
-                metrics["nodejs_memory_heap_total_bytes"].set(memoryUsage.heapTotal);
-            }
-            if (metrics["nodejs_memory_heap_used_bytes"]) {
-                metrics["nodejs_memory_heap_used_bytes"].set(memoryUsage.heapUsed);
-            }
+    const metricsMiddleware = function(req,res) {
+        let memoryUsage = process.memoryUsage();
+        if (metrics["nodejs_memory_heap_total_bytes"]) {
+            metrics["nodejs_memory_heap_total_bytes"].set(memoryUsage.heapTotal);
+        }
+        if (metrics["nodejs_memory_heap_used_bytes"]) {
+            metrics["nodejs_memory_heap_used_bytes"].set(memoryUsage.heapUsed);
+        }
 
-            res.contentType("text/plain")
-                .send(factory.promClient.register.metrics());
-            return;
+        res.contentType("text/plain").send(factory.promClient.register.metrics());
+        return;
+    };
+
+    const middleware = function (req, res, next) {
+        if (opts.autoregister && req.path == "/metrics") {
+            return metricsMiddleware(req,res);
         }
 
         if (opts.excludeRoutes && matchVsRegExps(req.path, opts.excludeRoutes)) {
@@ -127,8 +130,8 @@ function main(opts) {
     middleware.metricTemplates = metricTemplates;
     middleware.metrics = metrics;
     middleware.promClient = factory.promClient;
-
+    middleware.metricsMiddleware = metricsMiddleware;
     return middleware;
 }
 
-module.exports = main;
+module.exports = main;