OpenTofu Support

[cameronattard]

Is your feature request related to a problem? Please describe.
Per https://opentf.org/announcement, a new fork of Terraform, OpenTF is being created.

Describe the solution you'd like
Allow using tfswitch to install and manage OpenTF versions in addition to Terraform versions.

[nitrocode]

Wouldn't something like the --mirror flag work for opentf ?

https://github.com/warrensbox/terraform-switcher#use-custom-mirror

[roni-frantchi]

Wouldn't something like the --mirror flag work for opentf ?

Hey @nitrocode - not quite.
Although we are looking to be fully compatible with legacy Terraform, the binary name, command (terraform vs opentf) are all going to be different.

[kislerdm]

Hey folks! tofu support would be indeed quite useful. WDYT about separating managers and introducing the tool to manage tofu versions only? So it'd be an implementation of tfswitch interface/CLI commands, but called tofuswitch.

The main motivation: to separate concerns because tofu shall be treated as a standalone software independent of terraform when it comes to distribution. It'd enable for clean migration of CI pipelines etc.

[nitrocode]

Same issue that affects listing versions in mirrors will also affect opentofu since there isn't a single non-paginated url containing every opentofu release.

Related issue

• Issue when configuring Artifactory mirror: cannot get list from mirror #311

[nitrocode]

An option might be to switch from downloading terraform releases from the hashicorp page and download instead directly from github. Then it would be fairly simple to download the files from opentofu instead. The version check would then have to hit the github rest api or have an index url file passed in as an argument.

https://github.com/opentofu/opentofu/releases
https://github.com/hashicorp/terraform/releases

[nitrocode]

I made a page here that seems to line up similar to the terraform release page

https://nitrocode.github.io/opentofu/

[nitrocode]

We'll probably need a way of overriding the versionPrefix since opentofu's prefix is tofu_

It might also be nice to override the rest of these too.

terraform-switcher/main.go

Lines 40 to 49 in d7dfd1b

	const (
	defaultMirror = "https://releases.hashicorp.com/terraform"
	defaultBin = "/usr/local/bin/terraform" //default bin installation dir
	defaultLatest = ""
	tfvFilename = ".terraform-version"
	rcFilename = ".tfswitchrc"
	tomlFilename = ".tfswitch.toml"
	tgHclFilename = "terragrunt.hcl"
	versionPrefix = "terraform_"
	)

terraform-switcher/lib/install.go

Lines 15 to 22 in d7dfd1b

	const (
	installFile = "terraform"
	versionPrefix = "terraform_"
	installPath = ".terraform.versions"
	recentFile = "RECENT"
	defaultBin = "/usr/local/bin/terraform" //default bin installation dir
	tfDarwinArm64StartVersion = "1.0.2"
	)

[MatthewJohn]

I'm interested in this issue, as we use tfswitch (or terraform-switcher ;) ) in Terrareg.

Once concern I could imagine is that, you're using Hashicorp's HCL library for obtaining the constraint from a terraform {} block:

terraform-switcher/main.go

Lines 430 to 435 in d7dfd1b

	func installTFProvidedModule(dir string, custBinPath, mirrorURL *string) {
	fmt.Printf("Reading required version from terraform file\n")
	module, _ := tfconfig.LoadModule(dir)
	tfconstraint := module.RequiredCore[0] //we skip duplicated definitions and use only first one
	installFromConstraint(&tfconstraint, custBinPath, mirrorURL)
	}

Do we know if OpenTofu are sticking with this format (are they planning on changing the name at some point?) and I assume they have their own fork of the libraries:

terraform-switcher/main.go

Line 30 in d7dfd1b

"github.com/hashicorp/hcl2/hclparse"

Edit: It looks like OpenTofu are still using hashicorp's hcl library and that library hasn't changed it's license.

[yermulnik]

Do we know if OpenTofu are sticking with this format (are they planning on changing the name at some point?)

https://opentofu.org/

Can I use OpenTofu as a drop-in replacement for Terraform? Is OpenTofu suitable for production use?

Right now, OpenTofu is a drop-in replacement for Terraform, as it's compatible with Terraform versions 1.5.x and most of 1.6.x. You don’t need to make any changes to your code to ensure compatibility.

Hopefully OpenTofu isn't going to break core features and syntax compatibility in any near future 🤞🏻

[yermulnik]

@kvendingoldo While I have nothing against tenv (I tried it myself and, well, I prefer tfswitch, that I can run w/o any args to get just what I need — to switch to latest TF version allowed by the version constraint), I would like to ask to refrain from posting misleading info like «A lot of users switched to that tool to unify version management in the world of Terraform».

tenv:

tfswitch:

Please be respectful and mindful.

PS: To the extent possible we'll make our best to look into OpenTofu and Terragrunt support to be implemented in tfswitch (though it is not a high-priority task at the moment I think). PRs are welcome since tfswitch has gain some energy lately.

[nitrocode]

The tenv doesn't help me unfortunately because it's not the cli that I'd need here.

Atlantis (and other apps) uses the underlying terraform-switcher's go libs so those would need to be updated so we can keep the implementation of how atlantis autoupdates terraform the same as how it could autoupdate opentofu.

[yermulnik]

Atlantis (and other apps) uses the underlying terraform-switcher's go libs so those would need to be updated so we can keep the implementation of how atlantis autoupdates terraform the same as how it could autoupdate opentofu.

Thanks for the update and details.
Is what you're referring to related to #192 by any chance? I mean how the Atlantis (and other apps) utilizes tfswitch as a library?

While we're a bit short on human power to implement OpenTofu support, we welcome contributions and we'll try our best to review them as fast as our capacity allows.

[nitrocode]

It's unrelated to the issue you mentioned.

See this issue for the lower level details runatlantis/atlantis#4339.

[nitrocode]

Thanks for implementing this @MatthewJohn

@warrensbox will there be a release soon?

[MatthewJohn]

Thanks for implementing this @MatthewJohn

@warrensbox will there be a release soon?

We're just doing some testing at the moment on the alpha release of this :)

[warrensbox]

Opentofu feature was released on https://github.com/warrensbox/terraform-switcher/releases/tag/v1.2.0

Latest bug fixed: v1.2.2 (mostly related to windows)