Add basic support for Docker + Compose, refs #9406

[sevein]

Redmine: https://projects.artefactual.com/issues/9406

Usage

You need a Docker host (Engine) or a cluster (Swarm) and Docker Compose in order to orchestrate all the containers.

Docker Machine can assist you to easily deploy Docker hosts locally or using virtual machines or even remotely (cloud or bare-metal). There is also a bundle with all the tools included available for Windows and OSX users: Docker Toolbox.

Our default environment is described in docker-compose.dev.yml, which is meant to be used by developers. Production environments can differ significantly in the way they are composed based on your resources. We may provide some examples in the future, but that's not in the scope of this pull request.

Once the dependencies are installed, check out the repository and run:

$ cd docker/
$ docker-compose -f docker-compose.dev.yml up -d
$ docker-compose -f docker-compose.dev.yml exec atom php symfony tools:purge --demo
$ docker-compose -f docker-compose.dev.yml exec atom make -C /atom/src/plugins/arDominionPlugin
$ docker-compose -f docker-compose.dev.yml restart atom_worker

Environment variables

When you start the artefactual/atom image, you can adjust a number of settings passing environment variables on the docker run command line or via the Docker Compose file.

Name	Default
ATOM_DEVELOPMENT_MODE	Off
ATOM_ELASTICSEARCH_HOST	Not provided
ATOM_MEMCACHED_HOST	Not provided
ATOM_GEARMAND_HOST	Not provided
ATOM_MYSQL_DSN	Not provided
ATOM_MYSQL_USERNAME	Not provided
ATOM_MYSQL_PASSWORD	Not provided
ATOM_PHP_MAX_EXECUTION_TIME	120
ATOM_PHP_MAX_INPUT_TIME	120
ATOM_PHP_MEMORY_LIMIT	512M
ATOM_PHP_POST_MAX_SIZE	72M
ATOM_PHP_UPLOAD_MAX_FILESIZE	64M
ATOM_PHP_MAX_FILE_UPLOADS	20
ATOM_PHP_DATE_TIMEZONE	America/Vancouver

[MikeFE]

2.1 has known issues that we need to resolve (unsponsored atm, #8675). Version 1.0 is the preferred version we instruct users to use for now.

[sevein]

AtoM doesn't work in strict mode, which is the default in MySQL 5.7!