Lint docker bake file

[lemeurherve]

What feature do you want to see added?

I learnt about hclfmt which checks and formats HCL files.

I'd like to add it in a validation step in the pipeline, but unfortunatelly the original repo is archived since 2018: https://github.com/fatih/hclfmt

I found that this code is also now living in https://github.com/hashicorp/hcl/blob/main/cmd/hclfmt/main.go, but didn't find ay corresponding release asset.

I compiled and used it locally with success against docker bake files:

$ hclfmt -check -w docker-bake.hcl

My question is: how could I integrate it in our repos?

Other similar tools are using docker images wrapped in scripts, ex: https://github.com/jenkinsci/docker/blob/master/tools/hadolint

Should I...

• Create a docker image based on https://github.com/hashicorp/hcl/blob/main/cmd/hclfmt/main.go
• Build https://github.com/hashicorp/hcl/blob/main/cmd/hclfmt/main.go on the fly? (Would require proper go tooling in agents, and would be a bit wasteful)
• Simply include my built version in the repo?
• Find another alternative?
• Give up?

Upstream changes

No response

Are you interested in contributing this feature?

Yes.

[lemeurherve]

FWIW, I also found out about https://notes.kodekloud.com/docs/Terragrunt-for-Beginners/Terragrunt-Commands/terragrunt-hclfmt, but they're not distributing their own CLI https://github.com/gruntwork-io/terragrunt/tree/main/cli/commands/hcl/format in their release assets.

I also tried to use terraform fmt linked from terragrunt doc (https://developer.hashicorp.com/terraform/cli/commands/fmt), but unfortunatelly it doesn't accept .hcl file:

$ terraform fmt docker-bake.hcl
│ Error: Only .tf, .tfvars, and .tftest.hcl files can be processed with terraform fmt

I searched for existing docker images, but the ones I found were either old, or from unknown users.
I don't know if I'm missing a good one, let me know if there is one appropriate.

[timja]

you tried packer fmt? https://developer.hashicorp.com/packer/docs/commands/fmt

[lemeurherve]

you tried packer fmt? https://developer.hashicorp.com/packer/docs/commands/fmt

$ packer fmt docker-bake.hcl
Error: encountered an error while formatting docker-bake.hcl

file docker-bake.hcl is not a HCL file

🙄 😓

Too bad, would have been a good one as we already have packer in our agents.

[apparentlymart]

Typically tools that use HCL are expected to provide their own built-in formatter, as you've seen above with both terraform fmt and packer fmt.

Those tools tend to include what the upstream hclfmt would do but also include language-specific additions for conventions that are unique to each tool's own language, since HCL is really more of a toolkit for building configuration languages rather than a configuration language itself.

The upstream hclfmt therefore serves more like an example for tool implementers to start from than as a tool intended for end-user use. I wonder if the maintainers of docker buildx would be open to including a similar tool in their own program, similar to those in Terraform and Packer. 🤔

(Note: I formerly worked on HCL, but I am not a current maintainer of it and cannot speak on behalf of its current maintainers, nor influence whether and how they distribute the hclfmt tool. I'm just sharing this as a possible alternative.)

[lemeurherve]

Interesting, thanks for the info @apparentlymart!