`--docker-image` should imply `--docker`

[angerman]

Either I'm missing something, or I'm doing something wrong. Both are likely.

I have two docker images, purely to build for different deployments. Primarily I don't want to build with docker, hence I have the following in stack.yaml.

docker:
  enabled: false

When trying to locate the produced product, using stack --docker-image target/debian8.3 path --dist-dir, I get the exactly same result as if I had omitted the --docker-image argument. To get the actual path for the products, I need to specify --docker --docker-image target/debian8.3.

So we have:

stack --docker-image target/debian8.3 path --dist-dir == stack path --dist-dir

where I would have expected

stack --docker-image target/debian8.3 path --dist-dir == stack --docker --docker-image target/debian8.3 path --dist-dir

Should --docker-image not imply --docker?

[mgsloan]

Makes sense to me! PRs appreciated :)

[angerman]

I'm not sure if this is part of a larger theme? Should maybe all --docker-* commands imply --docker?

[mgsloan]

Yeah, probably makes sense. It gets a little weird with options like --no-docker-registry-login, though.

@borsboom What do you think about this? Convenient, or too magical?

[borsboom]

I'm on the fence about this, but in a project's stack.yaml, the presence of a docker: section implies that docker is enabled, so it would be consistent if the presence of any --docker* argument did the same on the command-line. Just make sure that if something like --docker-image=foo --no-docker is on the command-line, docker is still disabled (that the later --no-docker overrides the implied --docker).

[angerman]

My primary concern is that --docker-image without --docker seems to be a nonsensical construction. Maybe I'm seeing this wrong. But what does --docker-image without --docker or --no-docker actually mean?