From d088834026364fa5f20506369124acbd298b5c24 Mon Sep 17 00:00:00 2001
From: luzzi <christopher.luzzi@student.reutlingen-university.de>
Date: Tue, 29 Nov 2022 18:43:28 +0100
Subject: [PATCH] code commented
---
application/Dockerfile | 9 +++++++++
application/metrics.js | 7 +++++--
application/server.js | 2 ++
3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/application/Dockerfile b/application/Dockerfile
index a4c9aa6..3767c31 100644
--- a/application/Dockerfile
+++ b/application/Dockerfile
@@ -1,10 +1,19 @@
+# Node alpine is used as base for the image.
+# The node alpine is the lightweight version of node, that way the image stays as small in size as possible
FROM node:lts-alpine
ENV NODE_ENV=production
+# Here the Working directory is created and navigated to.
+# Into this Working directory we copy the code from the local maschine to the container.
WORKDIR /usr/src/CLOUD-COMPUTING_2022
+# Here we copy the package*.json and then install all the dependencies.
+# The Maven folder will not be copied to the Container as its on the dockerignore list.
+# That way we ensure all dependencies are correctly set inside the container
COPY ["package.json", "package-lock.json*", "npm-shrinkwrap.json*", "./"]
RUN npm install --production --silent && mv node_modules ../
+# After installing the dependencies we copy the actual code into the container and expose port 3000.
COPY . .
EXPOSE 3000
RUN chown -R node /usr/src/CLOUD-COMPUTING_2022
USER node
+# When running the Image in a container the application will start
CMD ["node", "server.js"]
diff --git a/application/metrics.js b/application/metrics.js
index 4909f3b..cee9465 100644
--- a/application/metrics.js
+++ b/application/metrics.js
@@ -1,14 +1,16 @@
const client = require('prom-client')
+//creating a registry where the metrics are collected
const register = new client.Registry()
register.setDefaultLabels({
app: 'cloud-computing-chat'
})
+//this enables collecting the defaul metrics the prom-client for node offers
client.collectDefaultMetrics({register})
-
+//here the metrics are defined
const msgSent = new client.Counter({
name: 'msgSent',
help: 'total number of messages sent'
@@ -35,13 +37,14 @@ const failedLogins = new client.Counter({
help: 'number of failed logins'
})
+//this registers the metrics in the registry we have created
register.registerMetric(registercounter)
register.registerMetric(msgSent)
register.registerMetric(msgLength)
register.registerMetric(onlineUser)
register.registerMetric(failedLogins)
-
+//exports the registry and the metrics to apply changes to metrics. e.g. inc the count for msgSent
exports.register = register
exports.msgSent = msgSent
exports.msgLength = msgLength
diff --git a/application/server.js b/application/server.js
index 977aad7..821e65d 100644
--- a/application/server.js
+++ b/application/server.js
@@ -88,6 +88,7 @@ app.get('/index', (req, res) => {
io.on('connection', (socket) => {
socket.on('chat message', (msg) => {
Metrics.msgSent.inc()
+ //this returns the count of words for every msg sent
var length = msg.split(' ').filter(word=> word !=='').length
Metrics.msgLength.observe(length)
io.emit('chat message', msg);
@@ -110,6 +111,7 @@ require(path.join(__dirname,'/app/routes/auth.routes'))(app);
require(path.join(__dirname,'/app/routes/user.routes'))(app);
+//exporting the collected metrics to prometheus metrics endpoint
app.get('/metrics', async (req, res) => {
res.set('Content-Type', Metrics.register.contentType)
res.end(await Metrics.register.metrics())
--
GitLab