src: add prometheus metrics to insult service

adjective/package.json

@@ -4,14 +4,9 @@
   "author": "Lance Ball, Red Hat, Inc.",
   "license": "MIT",
   "scripts": {
-    "pretest": "npm run lint",
-    "test": "tape test/*.js | tap-spec",
-    "test:coverage": "nyc tape test/*.js | tap-spec",
     "lint": "semistandard test/*.js index.js",
-    "prepare": "nsp check",
     "release": "standard-version",
-    "deploy": "nodeshift --strictSSL=false --metadata.out=deployment-metadata.json --nodeVersion=10.x --expose",
-    "postinstall": "license-reporter report",
+    "deploy": "nodeshift --strictSSL=false --nodeVersion=10.x --expose",
     "start": "node ."
   },
   "repository": {
@@ -33,14 +28,8 @@
   "homepage": "https://github.com/lance/elizabethan-insult",
   "devDependencies": {
     "nodeshift": "~1.7.1",
-    "nsp": "~3.2.1",
-    "nyc": "~11.7.3",
-    "rhoaster": "~0.2.0",
     "semistandard": "~12.0.1",
-    "standard-version": "^3.0.0",
-    "supertest": "~3.0.0",
-    "tap-spec": "~4.1.1",
-    "tape": "~4.6.2"
+    "standard-version": "^3.0.0"
   },
   "description": "Simple web service that returns a random Elizabethan adjective",
   "keywords": [
@@ -55,7 +44,6 @@
     "body-parser": "~1.18.2",
     "express": "~4.16.3",
     "kube-probe": "~0.3.1",
-    "license-reporter": "~1.2.1",
     "swagger-ui-express": "~3.0.9"
   }
 }

insult/assets/js/index.js

@@ -14,6 +14,7 @@ const circuitBreakerOptions = {
 
 const insult = circuitBreaker(getOrPostInsult, circuitBreakerOptions);
 const localStats = insult.hystrixStats.getHystrixStream();
+// insult.status.on('snapshot', console.log);
 localStats.on('data', message => updateStats(JSON.parse(message.substr(6))));
 
 new EventSource('/stats.stream').onmessage =
@@ -61,6 +62,7 @@ function clearInsultList (e) {
 }
 
 function updateStats (stats) {
+  console.log(stats);
   const [ serviceName, _ ] = stats.name.split(' ');
   $(`#${serviceName}_successes`).html(stats.rollingCountSuccess || stats.successes);
   $(`#${serviceName}_failures`).html(stats.errorCount || stats.errors);

insult/index.js

@@ -3,16 +3,21 @@ const path = require('path');
 
 const express = require('express');
 const swaggerUi = require('swagger-ui-express');
-
 const stats = require('./lib/stats');
 const api = require('./lib/insult');
 const probe = require('kube-probe');
 const port = process.env.PORT || 8080;
+const client = require('prom-client');
 
 const app = express();
 
 app.use('/stats.stream', stats);
 
+app.use('/metrics', (req, res) => {
+  res.set('Content-Type', client.register.contentType);
+  res.end(client.register.metrics());
+});
+
 // add swagger API docs
 app.use('/api-docs', swaggerUi.serve,
   swaggerUi.setup(require('./lib/insult.json')));
@@ -49,9 +54,6 @@ app.use('/js/jquery.js', express.static(
 app.use('/js/app.js', express.static(
   path.join(__dirname, 'public', 'app.js')));
 
-app.use('/licenses', express.static(
-  path.join(__dirname, 'licenses')));
-
 app.listen(port);
 
 console.log(`insult service listening on ${port}`);

insult/lib/insult.js

@@ -3,6 +3,15 @@
 const bodyParser = require('body-parser');
 const nounService = require('./noun-service');
 const adjectiveService = require('./adjective-service');
+const client = require('prom-client');
+
+const collectDefaultMetrics = client.collectDefaultMetrics;
+collectDefaultMetrics({prefix: 'insult_'});
+const durationMetric = new client.Histogram({
+  name: 'duration',
+  help: 'HTTP request response duration',
+  buckets: [0.1, 5, 15, 50, 100, 500]
+});
 
 function get (req, res) {
   res.type('application/json');
@@ -28,6 +37,7 @@ function post (req, res) {
 }
 
 function buildInsult () {
+  const end = durationMetric.startTimer();
   // call adjective and noun services
   return Promise.all([
     adjectiveService.get(),
@@ -39,7 +49,8 @@ function buildInsult () {
       adj2: words[1],
       noun: words[2]
     }))
-    .catch(e => console.error(`An unexpected error occurred: ${e}`));
+    .catch(e => console.error(`An unexpected error occurred: ${e}`))
+    .finally(end);
 }
 
 module.exports = exports = function insultApi (router) {