Implement default include

[dene14]

Describe the enhancement

Currently all of us have the pattern, where root.hcl or such is included in ALL project terragrunt.hcl file. So maybe we can introduce envvar and flag that would make possible to include specific file into each project?

Additional context

I'm using terragrunt across multiple different providers and "common" configuration has to be split in two files: root.hcl and provider.hcl whereas latter contains specific configuration for the provider.

[yhakbar]

Hey @dene14 ,

I bet this would be very convenient functionality, but it wouldn't be simple to implement.

For example, let's say you have one terragrunt.hcl file that's reading another via read_terragrunt_config. Which one should do the include? Both? Neither? How would the parser know?

What happens if the same file is included twice, once in HCL and once via a flag?

How would a user joining a Terragrunt project know that there's an expectation for everyone to set the flag before using any of the units?

Marking this as needs design. It might be better to have an RFC for functionality this major.