Hello,
I don't really know where to put an example about gitlab, but this is how I do it

See https://docs.gitlab.com/ee/user/infrastructure/terraform_state.html for more information

To use inside gitlab-ci and locally, I have done his configuration
config/boot.rb:

ENV['CI_PROJECT_ID'] ||= '<your project id>'
ENV['CI_API_V4_URL'] ||= 'https://gitlab.com/api/v4'
ENV['CI_JOB_USERNAME'] ||= 'gitlab-ci-token'
ENV['CI_JOB_TOKEN'] ||= 'you-must-defined-a-gitlab-PAT'
ENV['TF_URL'] = "#{ENV['CI_API_V4_URL']}/projects/#{ENV['CI_PROJECT_ID']}/terraform/state"

test/config/terraform/backend.tf:

terraform {
  backend "http" {
    address = "<%= ENV['TF_URL'] %>/<%= expansion(':ACCOUNT-:REGION-:ENV-:TYPE_DIR-:MOD_NAME') %>"
    lock_address = "<%= ENV['TF_URL'] %>/<%= expansion(':ACCOUNT-:REGION-:ENV-:TYPE_DIR-:MOD_NAME') %>/lock"
    unlock_address = "<%= ENV['TF_URL'] %>/<%= expansion(':ACCOUNT-:REGION-:ENV-:TYPE_DIR-:MOD_NAME') %>/lock"
    username = "<%= ENV['CI_JOB_USERNAME'] %>"
    password = "<%= ENV['CI_JOB_TOKEN'] %>"
    lock_method = "POST"
    unlock_method = "DELETE"
    retry_wait_min = 5
  }
}

Note:

• CI_PROJECT_ID, CI_API_V4_URL and CI_JOB_TOKEN is defined by gitlab automatically in the gitlab-ci, it's only for local usage that I define it ;)

The docs indicate the ability to layer tfvars using env based folders here and here. The first section (full-layering) seems to indicate this is "simple layering" but mentions the TS_ENV var without much explanation. The second section (extra) indicates the use of TS_ENV to organize based on env folders but doesn't explain.

Through trial and error I've learned that I need set both TS_ENV and TS_EXTRA like so: TS_ENV=$TS_ENV; TS_EXTRA=$TS_ENV/base. I think the Docs could use some added context here. Ideally, this should be supported out-of-the-box IMHO.

Hello,
in the documentation of terrafile usage, there is example about using the provided example, but not how to use it from the module.

So is this proper usage?

Terrafile

mod "foo", source: "[email protected]:bar/baz.git"

module "stuff" {
  source = "vendor/modules/foo"
}

If yes, add this example could be a nice usage.