Docker Compose MySQL

Published: 2 January 2021

Prerequisites

Docker desktop configured on the machine.

Docker enables us to separate applications from infrastructure so that we can deliver applications quickly. Today, docker is one of the standards to build and share containerized applications .

Docker helps developers recreate exact copy of development and production environments. Though running a database instance in docker comes with other challenges, this post shows how quick it is to run a mysql database instance using docker compose for development purposes.

This example below is tested on windows 10 with docker desktop version 3.0.0 running on WSL2.

Create a docker compose file docker-compose.yml in the directory of your choice and copy the contents below in the file.

version: "3.4"

services:
  mysqldb:
    image: mysql:8.0.20
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: strongpassword!
      MYSQL_USER: usermysql
      MYSQL_PASSWORD: strongdbpassword!
      MYSQL_DATABASE: customerdb
    ports:
      # host : container
      - "33061:3306"

Let us go through what each line does in docker-compose.yml
- Version specifies the compose file version used . We are using the version 3.4 , for details about the version you can refer the docker documentation.
```
version: "3.4"
```
- mysqldb is the name of the service we create
```
services:
  mysqldb:
```
- We specify the mysql docker image with the version to pull from the docker hub repository. Restart parameter specifies the docker image to restart in case of any unexpected failures
```
image: mysql:8.0.20
restart: always
```
- The environment variables for our mysql instance goes here .
```
environment:
  MYSQL_ROOT_PASSWORD: strongpassword!
  MYSQL_USER: usermysql
  MYSQL_PASSWORD: strongdbpassword!
  MYSQL_DATABASE: customerdb
```
- To access the database instance from your host we map the host port (ex. 33061) to the container port (ex. 3306).
```
ports: -'33061:3306'
```
Open the windows terminal /powershell and in the repository where we had saved the docker-compose.yml file execute the following command.

docker-compose up

Try to connect to the database from mysql workbench using the credentials specified in environment variables and on port 33061.

We have seen a mysql instance running as as docker image using compose file. To move this in production learn more about volumes for data persistence .