Terraform: Support colocation of modules with the same basename

[VJftw]

This PR fixes support for the colocation of Terraform modules that have the same basename. Currently, this Terraform tool only copies the basename of the directory name, into the colocated ./modules/ folder in terraform_roots. For example, the current behaviour is:

• Given a terraform_module at //modules/my_module_a/gcp:gcp (plz-out/gen/modules/my_module_a/gcp/gcp)
• The tooling currently copies this to ./modules/gcp.

This means that any other modules with the same basename will clash, For example:

• Given a terraform_module at //modules/my_module_a/gcp:gcp (plz-out/gen/modules/my_module_a/gcp/gcp)
• The tooling currently copies this to ./modules/gcp.
• Given another terraform_module at //modules/my_module_b/gcp:gcp (plz-out/gen/modules/my_module_b/gcp/gcp)
• The tooling currently copies this to ./modules/gcp, clashing with the other module.

This PR fixes this by changing the behaviour to:

• Given a terraform_module at //modules/my_module_a/gcp:gcp (plz-out/gen/modules/my_module_a/gcp/gcp)
• The tooling now copies this to ./modules/modules/my_module_a/gcp/gcp.
• Given another terraform_module at //modules/my_module_b/gcp:gcp (plz-out/gen/modules/my_module_b/gcp/gcp)
• The tooling now copies this to ./modules/modules/my_module_b/gcp/gcp.

I've also added another exclusion pattern for *.tfstate files to not be removed from /tmp/please/... so that people can still use non-remote terraform state (with its disadvantages) for demoing/testing purposes.

[lambchr]

changes lgtm, will give it a tick when the CircleCI tests pass :)

[Tatskaari]

changes lgtm, will give it a tick when the CircleCI tests pass :)

CircleCI tests are a little unloved. I'm planning to move things out of this repo into their own plugins, a bit like this: https://github.com/please-build/proto-rules

Happy to land this if the code looks good. We can also talk about migtating this to thought-machine/terraform-rules or something.

[VJftw]

I'm planning to move things out of this repo into their own plugins, a bit like this: https://github.com/please-build/proto-rules We can also talk about migtating this to thought-machine/terraform-rules or something.

Awesome! I'm keen for this too, really excited to see what we can do with the new plugin style of things too, I can imagine this being much easier to maintain 👌