Docker Compose
it is a microservice approach to create containers and manage containers for orchestration.
docker-compose is a tool for defining and running multi-container Docker applications. With docker-compose, you use a YAML file to configure your application’s services. Then, with a single command, you create and start all the services from your configuration.
Using Compose is basically a three-step process:
1. Define your app’s environment with a Dockerfile so it can be reproduced anywhere.
2. Define the services that make up your app in docker-compose.yml so they can be run together in an isolated environment.
3. Run docker-compose up and Compose starts and runs your entire app.
Docker Compose commands:
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docker-compose up -d
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This will create a network,
and create the containers as per defined in the docker-compose.yml file
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docker-compose down
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This will stop and remove
the containers then it will remove the network. The containers stopped and
removed are as of defined in the docker-compose.yml file.
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docker-compose scale db=2
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If for exam[le in the
docker-compose.yml file, you specified a db container, using the scale
command, it will create for you 2 db containers.
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Install Docker compose filesudo curl -L "https://github.com/docker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
chmod +x /usr/local/bin/docker-compose
docker-compose --version
Example 1:version: '3.3'
services:
db:
image: mysql:5.7
volumes:
- db_data:/var/lib/mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: somewordpress
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: wordpress
wordpress:
depends_on:
- db
image: wordpress:latest
ports:
- "80:80"
restart: always
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
WORDPRESS_DB_NAME: wordpress
volumes:
db_data: {}
docker-compose up -d
docker-compose down
Example 2
version: '3.3'
services:
db:
image: ramansharma95/mysql
webapp:
image: ramansharma95/webapp
ports:
- "80:80"
Run the following command in mysql container:
docker exec -it <<containerid>> bash
mysql -uroot -pwhizlabs
create database company;
use company;
create table employee ( name varchar(30), mobile varchar(30));
select * from employee;
