Support multiple docker-compose files

[davenuman]

Currently only the docker-compose.yml file is supported and if other docker-compose files exist in a project, they are ignored.

See also fd9aee2

[davenuman]

Here are my thoughts for expected usage:

$ # example 1
$ COMPOSE_FILE="docker-compose.yml:docker-compose.test.yml"
$ . activate
Bowline activated.
Commands added to shell: "test"
$ alias test
alias test='COMPOSE_FILE="docker-compose.yml:docker-compose.test.yml" docker-compose run --rm test test'
$
$ # example 2
$ unset COMPOSE_FILE
$ . activate
Bowline activated.
Commands added to shell: "test"
$ alias test
alias test='COMPOSE_FILE="docker-compose.yml" docker-compose run --rm test test'

Also, one could add a export COMPOSE_FILE line to the project's activate script or source an env file which exports it for a consistent set of docker-compose files that are read by bowline.

[grugnog]

@davenuman a couple of thoughts:

• Supporting COMPOSE_FILE sounds like a good start, but some projects might want only persistent services in context, so that docker-compose up doesn't start random dev/test commands. Technically this is possible, but you would need to change the value of COMPOSE_FILE in the activate script after bowline runs, which seems a bit complex.
• I was thinking it might be good to have some separate variable, perhaps BOWLINE_COMPOSE_FILE which, iff set, is used instead of the COMPOSE_FILE variable. BOWLINE_COMPOSE_FILE could of course include COMPOSE_FILE by reference, if the project wanted to supplement COMPOSE_FILE).
• It might also be interesting to allow this to support masks (for example docker-compose.test.*.yml) so that compose files could be added/removed without needing to update the list - this would sacrifice sort control (if used), but I think that is really more of a factor with services than commands.

So I think it would behave like this:

$ COMPOSE_FILE="docker-compose.yml:docker-compose.test.yml"
# In this case, lets say the project just wants to extend the COMPOSE_FILE list, so it is included, like with $PATH
$ BOWLINE_COMPOSE_FILE="${COMPOSE_FILE}:docker-compose.cli.*.yml"
$ ls docker-compose.cli.*.yml
docker-compose.cli.foo.yml
docker-compose.cli.bar.yml
$ . activate
Bowline activated.
Commands added to shell: "test,foo,bar"
$ alias test
alias test='COMPOSE_FILE="docker-compose.yml:docker-compose.test.yml:docker-compose.cli.foo.yml:docker-compose.cli.bar.yml" docker-compose run --rm test test'
$ alias foo
alias foo='COMPOSE_FILE="docker-compose.yml:docker-compose.test.yml:docker-compose.cli.foo.yml:docker-compose.cli.bar.yml" docker-compose run --rm foo foo'
$ alias bar
alias bar='COMPOSE_FILE="docker-compose.yml:docker-compose.test.yml:docker-compose.cli.foo.yml:docker-compose.cli.bar.yml" docker-compose run --rm bar bar'