Atlantis

is not a bad idea actually and it could be somehow tight to provider policies in a way that prevent people to install certain providers

but TF needs to change part of the source code to gain full functionality

We use atlantis to pull from private repos so atlantis already supports private registries.

I would use private repos in github (or your vcs of choice) as a private registry

Have you had difficulty using private repos as your private tf module registry?

Also what open source modules did you have issues with? Have you tried terraform-aws-modules or cloudposse modules?

that's the current model we use. it does prevent doing version range pinning, as you can only use ref for VCS to specify version, and that must be exact.

i'm currently investigating <https://github.com/MatthewJohn/terrareg> , which might actually suite our needs

<https://github.com/hashicorp/terraform/issues/31134> keep this in mind