Docker compose support for dynamic inclusion and exclusion of services

[ManuGowda]

Expected behavior

Having a dynamic way of services inclusion and exclusion will be flexible and more convenient.

Actual behavior

Currently, docker-compose.yml has services commented by default which is not mandatory, the user has to uncomment to enable these services.

Which version(s) does this affect? (Environment, OS, etc...)

[fchavant]

This should be doable using multiple compose files.

[fchavant]

Here is what we can do:

• have a docker-compose.yml with just the basics (postgres, core with sane config and no comment)
• an empty docker-compose.override.yml that people can use to customize their setups
  and also:
• a docker-compose.make.yml that'll be used by make coldstart (that's on less service in the docker-compose.yml)
• a docker-compose.redis.yml that can be used optionally

The current comments I would replace by a few examples of the most useful environment variables in the README.md.

@ManuGowda what do you think?

[ManuGowda]

Looks like a clean approach to me 👍