3.7. Setting Up Docker

Docker is a tool designed to make it easier to create, deploy, and run applications by using containers. Containers allow a developer to package up an application with all of the parts it needs, such as libraries and other dependencies, and ship it all out as one package. By doing so, thanks to the container, the developer can rest assured that the application will run on any other Linux machine regardless of any customized settings that machine might have that could differ from the machine used for writing and testing the code.

3.7.1. Dependencies

The following is needed to properly setup Docker.

Once you’re done, simply cd to your project and run docker-compose up. This will initialize and start all the containers.

3.7.2. Services Available

You can access your application and the following services via localhost.

Service Address outside containers
Web Server http://127.0.0.1:8082
MySQL 127.0.0.1:8084

3.7.3. Internal Routing

You’ll need to configure your application to use any services you enabled:

Service Hostname Port number
php-fpm php-fpm 9000
MySQL mysql 3306 (default)
Redis redis 6379 (default)
ElasticSearch elasticsearch 9200 (HTTP default) / 9300 (ES transport default)

3.7.4. Docker Cheatsheet

Note: you need to cd first to where your docker-compose.yml file lives.

  • Start containers in the background: docker-compose up -d
  • Start containers on the foreground: docker-compose up. You will see a stream of logs for every container running.
  • Stop containers: docker-compose stop
  • Kill containers: docker-compose kill
  • View container logs: docker-compose logs

Execute command inside of container: docker-compose exec SERVICE_NAME COMMAND where COMMAND is whatever you want to run. The following items are example commands.

  • Shell into the PHP container, docker-compose exec php-fpm bash
  • Run Cradle CLI, docker-compose exec php-fpm bin/cradle
  • Open a mysql shell, docker-compose exec mysql mysql -uroot -pCHOSEN_ROOT_PASSWORD

3.7.5. Recommendations

It’s hard to avoid file permission issues when fiddling about with containers due to the fact that, from your OS point of view, any files created within the container are owned by the process that runs the docker engine (this is usually root). Different OS will also have different problems, for instance you can run stuff in containers using docker exec -it -u $(id -u):$(id -g) CONTAINER_NAME COMMAND to force your current user ID into the process, but this will only work if your host OS is Linux, not mac. Follow a couple of simple rules and save yourself a world of hurt.

  • Run composer outside of the php container, as doing so would install all your dependencies owned by root within your vendor folder.
  • Run commands (ie. bin/cradle) straight inside of your container. You can easily open a shell as described above and do your thing from there.