feat: support passing workspaces to include in the config

[mmalecki]

Pull Request

Related Github Issues

• [none]

Description

This allows us to generate Atlantis configurations including hard-coded
workspaces, as passed in by the user.

We use workspaces (as opposed to Terragrunt's recommended way of
directories) to separate our environments. This allows us to generate a
Atlantis configuration containing "blessed" environments we want to
operate via Atlantis.

Apologies for the awkward Golang. I don't write it daily, so I'm sure there's a neater way to solve this. I'd appreciate any guidance here.

Security Implications

• [none]

System Availability

• [none]

[dennislapchenko]

Have a similar request, to be able to say:

locals {
  atlantis_workspace = "my_workspace"
}

alongside a general --create-workspaces.

This would allow joining some modules into one workspace for various reasons. I suspect it would be another feature?

[mmalecki]

@dennislapchenko yeah, I think so. Just taking a look at the surrounding code in createProject, since we appear to have the locals handy, you could just set project.Workspace = locals.Workspace.

I rebased this off master and added some tests for preserving and updating projects with workspaces set, since I added some complexity there.