Advantages of Using Docker Compose in Your Projects

It’s that time of the year again when I get a larger drive, refresh my operating system, and back up important files.

Ever since I’ve settled on having my home folder always be on a separate drive, it’s been really easy to change operating systems, and even moving to a different (more powerful) computer isn’t as much of a chore. If I need to upgrade storage capacity, I just copy everything in my home folder onto the new drive (either by imaging or using rsync) and then make sure that, when I set up the new OS, the new drive is mounted in /home.

One thing that’s been really convenient for me is the ability to move database data along with my home folder. This has been largely because I’ve been using Docker (and Docker Compose) more and more in my projects.

For example, one of the docker-compose.yml configurations I have for work looks like this:

version: '3.2'
services:
  mysql:
    # image: circleci/mysql:5.7-ram # no persistence, but very fast
    image: circleci/mysql:5.7
    command: --ssl=0
    restart: always
    expose:
      - "3306"
    ports:
      - '13306:3306'
    shm_size: '2gb'
    environment:
      MYSQL_DATABASE: ejbdev
      MYSQL_ROOT_PASSWORD: toor
    volumes:
      - ./mysql-data:/var/lib/mysql
      # - /usr/local/var/mysql:/var/lib/mysql # use data from local mysql service

  adminer:
    image: adminer
    restart: always
    ports:
      - 8888:8080
    environment:
      ADMINER_DEFAULT_SERVER: mysql

  redis:
    image: "redis:alpine3.11"
    restart: always
    ports:
      - "16379:6379"
    volumes:
      - ./redis-data:/var/lib/redis
      - ./redis.conf:/usr/local/etc/redis/redis.conf
    environment:
      - REDIS_REPLICATION_MODE=master

You’ll notice that the postgres and the redis data volumes are being mounted on the same folder as the docker-compose.yml file. This makes it so the data is located along with the code; that means whenever I have to move drives or move the work folder into another location, the data I’ve been working on comes along with it.

This makes for really fast setup times whenever I need to switch work machines: either just move the drive or copy the contents, run docker-compose up and let Docker download the images, and once the services come online, everything works as before. The only difference is that I now have faster/larger storage. :)

I can wholeheartedly recommend the advice given at https://hackernoon.com/dont-install-postgres-docker-pull-postgres-bee20e200198. I’d add that, aside from Docker, you should use Docker Compose so you don’t have to memorize all those fancy command-line invocations. Write them once and just run docker-compose up.