Add active terraform dependency collection for automerge classification

[Copilot]

This change adds a dedicated terraform dependency collection to automerge routing, including Terraform, OpenTofu, and Terragrunt-related files. The new collection is configured as active so terraform-only dependency update PRs can be classified and proceed through automerge gates.

• Collection config update

  • Added a new terraform entry to config/obs/automerge-dependency-collections.json.
  • Marked the collection as active: true.
  • Included Terraform and related file patterns:
    • **/*.tf
    • **/*.tfvars
    • **/*.tfvars.json
    • **/.terraform.lock.hcl
    • **/terragrunt.hcl
    • **/.opentofu-version
    • **/.terraform-version
    • **/.terragrunt-version

• Classifier coverage

  • Extended tests/unit/classifyAutomergeDependencyCollection.test.ts with a focused unit test that verifies terraform-only changes classify as:
    • status: 'allowed'
    • collectionId: 'terraform'

Example config fragment:

{
  "id": "terraform",
  "description": "Terraform/OpenTofu/Terragrunt dependency and lockfile updates",
  "active": true,
  "file-glob": [
    "**/*.tf",
    "**/*.tfvars",
    "**/*.tfvars.json",
    "**/.terraform.lock.hcl",
    "**/terragrunt.hcl",
    "**/.opentofu-version",
    "**/.terraform-version",
    "**/.terragrunt-version"
  ]
}

[fr4nc1sc0-r4m0n]

LGTM

[Copilot]

Pull request overview

Adds an active terraform dependency collection to the Observability automerge dependency-collection classifier so Terraform/OpenTofu/Terragrunt-only dependency update PRs can be routed through the “allowed” automerge path.

Changes:

• Added a new active terraform collection with Terraform/OpenTofu/Terragrunt file globs to config/obs/automerge-dependency-collections.json.
• Added a unit test ensuring terraform-only changed files classify as { status: 'allowed', collectionId: 'terraform' }.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
config/obs/automerge-dependency-collections.json	Adds an active terraform collection with Terraform/OpenTofu/Terragrunt-related file patterns for classification.
tests/unit/classifyAutomergeDependencyCollection.test.ts	Adds coverage to verify terraform-only changes are classified as allowed under the new collection.

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[v1v]

Can you confirm with @elastic/observablt-dx if they have any concerns? I don't recall they actually use terraform in any oblt-* repositories but just wanna play safe here

[fr4nc1sc0-r4m0n]

Can you confirm with @elastic/observablt-dx if they have any concerns? I don't recall they actually use terraform in any oblt-* repositories but just wanna play safe here

@elastic/observablt-dx do you have any concern about activating this dependency collection to allow the automerge on these related version bumps?

[Coolomina]

Can you confirm with @elastic/observablt-dx if they have any concerns? I don't recall they actually use terraform in any oblt-* repositories but just wanna play safe here

@elastic/observablt-dx do you have any concern about activating this dependency collection to allow the automerge on these related version bumps?

What effort is this PR part of?. We heavily rely on Terraform on oblt-framework.

What version will this config bump exactly?

[fr4nc1sc0-r4m0n]

Can you confirm with @elastic/observablt-dx if they have any concerns? I don't recall they actually use terraform in any oblt-* repositories but just wanna play safe here

@elastic/observablt-dx do you have any concern about activating this dependency collection to allow the automerge on these related version bumps?

What effort is this PR part of?. We heavily rely on Terraform on oblt-framework.

What version will this config bump exactly?

This is related with this issue https://github.com/elastic/observability-robots/issues/4425.
But @Coolomina let me clarify this because this is not going to bump any version.
What we are doing here is to enable the [automerge agentic workflow](https://github.com/elastic/oblt-aw/blob/main/docs/workflows/oblt-aw-automerge.md) (which already contains a multiple internal pre evaluations before: dependency-review, required checks, etc.) when the bump is being categorized as one of the active categories (see https://github.com/elastic/oblt-aw/blob/main/config/obs/automerge-dependency-collections.json).
When a version bump will be categorized as an active category? Basically both things:

• When the file where the bump happens match the any of the file-glob pattern (see https://github.com/elastic/oblt-aw/blob/main/config/obs/automerge-dependency-collections.json#L9)
• When the matched category is set as active (see https://github.com/elastic/oblt-aw/blob/main/config/obs/automerge-dependency-collections.json#L8)

So basically what we are pretending to do here in natural language is: should we merge automatically the PRs that contains bump versions related with terraform files that are categorized as moderate to low-risk by the dependency review agentic workflow and passes all the additional validations?