Run conftest on tfmigrate-plan

Hi, this is a some kind of bug report, and feature request.

I noticed that the conftest validation doesn’t run during tfmigrate-plan action. We noticed that the resource definition violating our conftest policy in terraform-plan after tfmigrate’d.

I think this part in terraform-plan should also be in tfmigrate-plan. https://github.com/suzuki-shunsuke/tfaction/blob/91916f7cf7d2df7f8a01357f5d15e07a603d0555/terraform-plan/main.sh#L30-L38

Furthermore, there’s a edge case related to this: skip: prefix used in tfmgirate multi-state migration. If a working directory that was added resources skipped tfmigrate-plan by skip:xxx label, this would cause an issue. To fix the case, I propose splitting build matrix from [terraform, tfmigrate] to [terraform, tfmigrate, conftest (or validation)]. What do you think?

[kyontan]

Thanks for your great work! I’ll try the new version.

[suzuki-shunsuke]

I understood why TF_CLI_ARGS_plan="-out=tfplan.out doesn’t work. https://github.com/minamijoyo/tfmigrate/issues/106#issuecomment-1243826555