Docker Compose

Docker Compose makes it easier to configure and run applications made up of multiple containers. All containers are defined in one YAML file and then run using a single command

Each Container will run a stand-alone application and it can communicate with other containers present in the same host

Eg: MEAN Stack Application [MongoDB, ExpressJS, Angular, NodeJS] using different containers.

docker-compose.yml (markup language)→ To run more than one container for a service

Eg: docker-compose.yml

version: '3.0' # specify docker-compose vesion

#Define the services/containers to be run

services:

angular: # name of the first service

build: angular-app # specify the directory of Dockefile for angular service

ports:

- "4200:4200" #specify ports mapping

express: # name of the second service

build: express-server # specify the directory of Dockefile for express service

ports:

- "3000:3000" #specify ports mapping

links:

- database # link this service to the database service

database: # name of the third service

image: mongo # specify image to build container from

ports:

- "27017:27017" #specify ports forewarding

Terminal Commands:

#This commands are executed in the directory where **YAML** file is present for bulding the Compose.

**docker-compose build -> #**to build the compose using YAML file

**docker-compose up ->** #to start compose container srevice