Add --terragrunt-include-module-prefix option

[maciasello]

Description

Fixes #1194 .

TODOs

Read the Gruntwork contribution guidelines.

• Update the docs.
• Run the relevant tests successfully, including pre-commit checks.
• Include release notes. If this PR is backward incompatible, include a migration guide.

Release Notes (draft)

Added --terragrunt-include-module-prefix flag to include module dir prefix in Terraform output

Migration Guide

[maciasello]

This PR adds a flag to enable the prepending of prefixes.

Also it may be reasonable to trim the prefix to be relative to a common parent of the modules or to cwd (or other place) - please guide me what is the suggested approach. In logs prefix key is an absolute path - I started from that.

[denis256]

I was wondering why output should be buffered and not directly written to pf.writer?

[maciasello]

I did not want to call the underlying pf.writer for each character as it may degrade performance.

This buffering does not cross single .Write() call span so it will not create a "typical" buffered i/o effect.

Still, it needs an additional memory and one copying of the input []byte. If you feel there is more efficient way I would be more than happy to apply it.

[denis256]

Actually, output include module path, not module name.

[maciasello]

Corrected the doc.

[denis256]

Noticed that terragrunt-include-module-prefix is not listed in the help output

$ terragrunt --help | grep terragrunt-include-module-prefix
$

[maciasello]

Included the info in help output. Is there any other place the help should be updated?

[maciasello]

Added tests for PrefixWriter for a complete picture. Somehow missed that initially.

[denis256]

[INFO] Initializing environment for https://github.com/gruntwork-io/pre-commit.
Terraform fmt............................................................Passed
goimports................................................................Failed
- hook id: goimports
- files were modified by this hook

util/prefix-writer_test.go

[maciasello]

[INFO] Initializing environment for https://github.com/gruntwork-io/pre-commit.
Terraform fmt............................................................Passed
goimports................................................................Failed
- hook id: goimports
- files were modified by this hook

util/prefix-writer_test.go

Fixed.

[lorengordon]

Also it may be reasonable to trim the prefix to be relative to a common parent of the modules or to cwd (or other place) - please guide me what is the suggested approach. In logs prefix key is an absolute path - I started from that.

Thanks! Where did this end up? Is the prefix the absolute path, or a relative path of some kind? I didn't see an example in the changed files...

[lorengordon]

Tested to find the answer myself, it is the absolute path...

[dhirschfeld]

Tested to find the answer myself, it is the absolute path...

Yeah, it's the absolute path:

[/home/sysop/code/github/dhirschfeld/azure-infra-test/terraform/dev/network]

That takes up a lot of screen real-estate. It would be great if the path could be relative to the cwd - i.e. running in the dev folder that would be:

[./network]

[AlDemion]

As a workaround you can utilize something like this
terragrunt run-all plan -lock=false --terragrunt-non-interactive | sed "s#$(pwd)/##g"