tiddying up code

node/app.js

@@ -1,28 +1,50 @@
-var express = require('express');
-var app = express();
-var mongoose = require('mongoose');
-var Schema = mongoose.Schema;
-var database = 'mongodb://' + process.env.mongousr + ':' + process.env.mongopwd + '@mongo:27017/test';
-var today = new Date();
+const express = require('express');
+const app = express();
+const mongoose = require('mongoose');
+const Schema = mongoose.Schema;
+const database = 'mongodb://' + process.env.mongousr + ':' + process.env.mongopwd + '@mongo:27017/test';
+const today = new Date();
 var counter = 0;
-var Prometheus = require("prom-client");
+const Prometheus = require("prom-client");
+
+// database connection (with retries)
+const options = {
+  autoIndex: false, // Don't build indexes
+  reconnectTries:30, // Retry up to 30 times
+  reconnectInterval: 500, // Reconnect every 500ms
+  poolSize: 10, // Maintain up to 10 socket connections
+  // If not connected, return errors immediately rather than waiting for reconnect
+  bufferMaxEntries: 0,
+  useNewUrlParser: true
+}
+
+const connectWithRetry = () => {
+  console.log('MongoDB connection with retry')
+  mongoose.connect(database, options).then(()=>{
+    console.log('MongoDB is connected')
+  }).catch(err=>{
+    console.log('MongoDB connection unsuccessful, retry after 5 seconds.')
+    setTimeout(connectWithRetry, 5000)
+  })
+}
 
 const libCounter = new Prometheus.Counter({
   name: 'lib_invocation_count',
-  help: 'A simple counter for app access during runtime created with unofficial prometheus nodejs library'
+  help: 'A simple counter for app access during runtime created with prometheus nodejs library'
 });
 
 const libUptime = new Prometheus.Counter({
   name: 'lib_upTime',
-  help: 'uptime A counter of the application\'s uptime in seconds.'
+  help: 'uptime A counter of the application\'s uptime in seconds created with prometheus nodejs library.'
 })
 
 console.log('mongousr: ', process.env.mongousr);
 console.log('mongopwd: ', process.env.mongopwd);
 
-// const collectDefaultMetrics = Prometheus.collectDefaultMetrics;
+// Prometheus Default Metrics collector
+const collectDefaultMetrics = Prometheus.collectDefaultMetrics;
 // Probe every 5th second.
-// collectDefaultMetrics({ timeout: 5000 });
+collectDefaultMetrics({ timeout: 5000 });
 
 // new schema model object based on the structure of what I want to put on MongoDB collection
 var testSchema = new Schema({
@@ -36,34 +58,32 @@ var testSchema = new Schema({
 // new object that will hold the data using model structure made above
 var colors = mongoose.model('colorName', testSchema);
 
-// Prometheus metrics
+// Prometheus metrics endpoint - Library
 app.get('/metrics', function(req, res){
-  // var now = new Date();
-  // var passedTime = now - today;
-  // res.writeHead(200, {'Content-Type':'text/plain'});
-  // res.write('# HELP uptime A counter of the application\'s uptime in millisenconds.' + '\n');
-  // res.write('# TYPE uptime counter' + '\n');
-  // res.write('uptime ' + passedTime + '\n');
-  // res.write('# HELP invocation_count A simple counter for app access during runtime' + '\n');
-  // res.write('# TYPE invocation_count counter'+ '\n');
-  // res.write('invocation_count ' + counter + '\n');
-  // res.end();
   libUptime.inc(Math.floor(process.uptime()));
   res.set('Content-Type', Prometheus.register.contentType)
   res.end(Prometheus.register.metrics())
-  res.end();
   libUptime.reset();
 });
 
-app.get('/env', function(req, res){
-  
-});
-
+// Prometheus metrics endpoint - Handmade
+app.get('/metrics2', function(req, res){
+  var now = new Date();
+  var passedTime = now - today;
+  res.writeHead(200, {'Content-Type':'text/plain'});
+  res.write('# HELP uptime A counter of the application\'s uptime in millisenconds.' + '\n');
+  res.write('# TYPE uptime counter' + '\n');
+  res.write('uptime ' + passedTime + '\n');
+  res.write('# HELP invocation_count A simple counter for app access during runtime' + '\n');
+  res.write('# TYPE invocation_count counter'+ '\n');
+  res.write('invocation_count ' + counter + '\n');
+  res.end();
+})
 
 app.get('/', (req, res)=>{
   res.json([{message:'yes, your nodejs app is really running'}]);
-  counter++;
-  libCounter.inc();
+  counter++; // for prometheus invocation_count metric
+  libCounter.inc(); // for prometheus lib_invocation_count metric
 });
 
 app.get('/info', function(req, res){
@@ -72,50 +92,13 @@ app.get('/info', function(req, res){
   });
 });
 
-app.get('/info/:name', function(req, res){
-  colors.find({color: req.params.name}).then(function(colors){
-    res.json(colors);
-  });
-});
-
-app.get('/colors', function(req, res){
-  colors.find({}).then(function (colors) {
-    res.json(colors);
-  });
-});
-
-app.get('/colors/query/:name', function(req, res){
-  res.send('color is ' + req.params.name);
-});
-
-app.post('/colors/add/:name', function(req, res){
+app.post('/info/add/:name', function(req, res){
   var item = {color: req.params.name};
   var data = new colors(item);
   data.save();
   res.send('color ' + req.params.name + ' added to database');
 });
 
-// database connection (with retries)
-const options = {
-  autoIndex: false, // Don't build indexes
-  reconnectTries:30, // Retry up to 30 times
-  reconnectInterval: 500, // Reconnect every 500ms
-  poolSize: 10, // Maintain up to 10 socket connections
-  // If not connected, return errors immediately rather than waiting for reconnect
-  bufferMaxEntries: 0,
-  useNewUrlParser: true
-}
-
-const connectWithRetry = () => {
-  console.log('MongoDB connection with retry')
-  mongoose.connect(database, options).then(()=>{
-    console.log('MongoDB is connected')
-  }).catch(err=>{
-    console.log('MongoDB connection unsuccessful, retry after 5 seconds.')
-    setTimeout(connectWithRetry, 5000)
-  })
-}
-
 connectWithRetry();
 
 app.listen(3001, () => {