{"id":28449,"date":"2015-10-18T17:38:25","date_gmt":"2015-10-18T12:08:25","guid":{"rendered":"http:\/\/www.tothenew.com\/blog\/?p=28449"},"modified":"2016-01-19T13:29:34","modified_gmt":"2016-01-19T07:59:34","slug":"running-multi-container-nodejs-application-using-docker-compose","status":"publish","type":"post","link":"https:\/\/www.tothenew.com\/blog\/running-multi-container-nodejs-application-using-docker-compose\/","title":{"rendered":"Running multi-container Nodejs application using docker-compose"},"content":{"rendered":"

This blog post is about using docker-compose, a tool provided by docker to define and run multi container application using a single command. It uses a docker-compose.yml file as default input file.
\n\"Dockercompose\"<\/p>\n

I got a use case which was to run a Nodejs application behind a Nginx acting as a reverse proxy in two different Docker containers. This can be achieved using Dockerfile but it has got its own constraints as only one image can be created using a Dockerfile. So, after the creation of two different images with Dockerfiles, we would have to create two containers separately\u00a0which were supposed to run in conjugation with each other.
\nThis did not seem to be a perfect solution for the problem scenario. After some search, I found docker-compose, read about it and concluded that it is the most apt tool to go with for the use case.<\/p>\n

Scenario:<\/strong> Running a Nodejs application in one container, and Nginx as a reverse proxy to Nodejs application in the second container using docker-compose.<\/p>\n

\"1-_MtS4HqN2srTcrSyet61DQ\"<\/p>\n

Before moving to docker-compose, I had already made Dockerfiles for both Nginx and Nodejs. So, I decided to reference these Dockerfiles in docker-compose.yml<\/strong>.<\/p>\n

Let\u2019s have a look at the directory structure we will be using:<\/p>\n

[js]root@singh ~\/node # ls -R
\n.:
\ndocker-compose.yml nginx nodejs<\/p>\n

.\/nginx:
\ndefault Dockerfile nginx.conf startUp.sh<\/p>\n

.\/nodejs:
\napp.js Dockerfile startUp.sh
\n[\/js]<\/p>\n

“nginx” directory contains Nginx\u2019s Dockerfile and other related files which we have referenced inside their respective Dockerfile as shown below:<\/p>\n

[js]root@singh ~\/node #cat nginx\/Dockerfile
\nFROM navjotece19\/nginx-as-a-proxy:v1.0
\nMAINTAINER NavjotSingh <navjot.singh[at]tothenew[dot]com>
\nADD default \/etc\/nginx\/sites-enabled\/default
\nADD nginx.conf \/etc\/nginx\/nginx.conf
\nADD startUp.sh \/root\/startUp.sh
\nRUN chmod +x \/root\/startUp.sh
\nCMD ["\/root\/startUp.sh"]
\n[\/js]<\/p>\n

We have added default, nginx.conf and startUp.sh files in Dockerfile whereas we have passed startUp.sh file as and argument to CMD for Nginx container:<\/p>\n

[js]root@singh ~\/node #cat nginx\/startUp.sh
\n#!\/bin\/bash
\n> \/var\/log\/nginx\/access.log
\n> \/var\/log\/nginx\/error.log
\n\/usr\/sbin\/nginx &
\ntail -f \/var\/log\/nginx\/access.log
\n[\/js]<\/p>\n

“default” file has proxy pass configuration, proxying to port 7777 to Nodejs container as shown below:<\/p>\n

[js]root@singh ~\/node #cat default
\nserver {
\n listen 80 default_server;
\n listen [::]:80 default_server ipv6only=on;<\/p>\n

root \/usr\/share\/nginx\/html;
\n index index.html index.htm;<\/p>\n

server_name localhost;
\n location \/ {
\n proxy_pass http:\/\/nodejs:7777;
\n }
\n}[\/js]<\/p>\n

“nginx.conf” has default Nginx configuration parameters.<\/p>\n

Lets move to the Nodejs directory which contains Dockerfile, app.js (print hello world) and startUp.sh.<\/p>\n

[js]root@singh ~\/node #cat Dockerfile
\nFROM navjotece19\/nodejs:v1.0
\nMAINTAINER AS-Support <navjot.singh[at]tothenew[DOT]com>
\nADD app.js \/root\/code\/app.js
\nADD startUp.sh \/startUp.sh
\nRUN chmod +x \/startUp.sh
\nCMD ["\/startUp.sh"]
\n[\/js]<\/p>\n

“navjotece19\/nodejs:v1.0” image has Nodejs already installed in it. We are adding “app.js” and “startUp.sh” files in Nodejs container and passing “startUp.sh” in CMD of Dockerfile.<\/p>\n

[js]root@singh ~\/node #cat app.js
\nvar express = require(‘express’);
\nvar app = express();<\/p>\n

app.get(‘\/’, function (req, res) {
\n res.send(‘Hello World!’);
\n});<\/p>\n

var server = app.listen(7777, function () {
\n var host = server.address().address;
\n var port = server.address().port;<\/p>\n

console.log(‘Example app listening at http:\/\/%s:%s’, host, port);
\n});
\n[\/js]<\/p>\n

[js]root@singh ~\/node #cat startUp.sh
\nFROM navjotece19\/nodejs:v1.0
\nMAINTAINER AS-Support <navjot.singh[at]tothenew[DOT]com>
\nADD app.js \/root\/code\/app.js
\nADD startUp.sh \/startUp.sh
\nRUN chmod +x \/startUp.sh
\nCMD ["\/startUp.sh"]
\n[\/js]<\/p>\n

Now, let’s create “docker-compose.yml” file. We have referenced the above two Dockerfiles inside it as shown below:<\/p>\n

[js]root@singh ~\/node #cat docker-compose.yml
\nnginx:
\n build: .\/nginx
\n ports:
\n – "8081:80"
\n container_name: nginx-reverse-proxy
\n links:
\n – nodejs:nodejs
\nnodejs:
\n build: .\/nodejs
\n container_name: nodejs
\n[\/js]<\/p>\n

First part is for “nginx” service providing the following details:<\/p>\n