如何在 docker-compose 中基于 RAILS 环境启动不同的服务

Question

I would like to start service-A, service-B, service-C if RAILS_ENV is development
I would like to start service-A, service-B, service-D if RAILS_ENV is staging
I would like to start service-A, service-B, service-E if RAILS_ENV is production

How should I override intelligently in docker-compose.yaml file.

service-C, service-D, service-E are not variants of the same service, but could be completely different containers as well

Answer 1

My suggestion would be to call docker-compose from a script.

If your docker-compose.yaml looks like this:

service-A:
    # Your service definition

service-B:
    # Your service definition
    depends_on:
        - service-A

service-C:
    # Your service definition
    depends_on:
        - service-B

service-D:
    # Your service definition
    depends_on:
        - service-B

service-E:
    # Your service definition
    depends_on:
        - service-B

Then, instead of calling docker-compose up , call a script that performs the conditional logic by checking environment variable RAILS_ENV, like this:

./start-services.sh

Where the script definition looks like this:

#!/bin/bash
if [ $RAILS_ENV== "development" ]
  then
  docker-compose up service-C
elif [ $TESTVAR == "staging" ]
  then
  docker-compose up service-D
elif [ $TESTVAR == "production" ]
  then
  docker-compose up service-E
else
  exit 1
fi

Of course, this implementation is a but unix-dependent, but I think it can be generalized to any operating system.

Answer 2

Docker-compose has overrides , you can have:

• shared base config in docker-compose.yml with service-A and service-B
• service-C config in docker-compose.override.yml for development (docker compose should pick up this one by default)
• service-E config in docker-compose.production.yml , and run like

  docker-compose -f docker-compose.yml -f docker-compose.production.yml up -d

• similarly for service-E in docker-compose.staging.yml