gh-action-terragrunt-apply action

This Terragrunt action based on dflook/terraform-github-actions.

This action applies a Terraform plan for each module in the provided path. The default behaviour is to apply the plan that has been added to a PR using the wayofdev/gh-action-terragrunt-plan action.

If the plan is not found or has changed, then the apply action will fail. This is to ensure that the action only applies changes that have been reviewed by a human.

You can instead set auto_approve: true which will generate a plan and apply it immediately, without looking for a plan attached to a PR.

NOTE: There are two apply strategies. Read about them bellow in Inputs section.

This github action uses --terragrunt-download-dir option to redirect cache in /tmp/tg_cache_dir.

Inputs

These input values must be the same as any wayofdev/gh-action-terragrunt-plan for the same configuration, except strategy because it is actual only for apply command. (unless auto_approve: true)

• path

  Path to the Terragrunt root module to apply

  • Type: string
  • Optional
  • Default: The action workspace

• tg_version

  Terragrunt version required to run the plan

  • Type: string
  • Optional
  • Default: 0.52.4

• tf_version

  Terraform version required to run the plan

  • Type: string
  • Optional
  • Default: 1.5.7

• parallelism

  Limit the number of concurrent operations

  • Type: number
  • Optional
  • Default: The terraform default (10)

• label

  A friendly name for the environment the configuration is for. This will be used in the PR comment for easy identification.

  If set, must be the same as the label used in the corresponding terragrunt-plan-all command.

  • Type: string
  • Optional

• destroy

  Set to true to destroy all resources.

  This generates and applies plans in destroy mode.

  • Type: boolean
  • Optional
  • Default: false

• auto_approve

  When set to true, generated plans are always applied.

  The default is false, which requires plans to have been approved through a pull request.

  • Type: boolean
  • Optional
  • Default: false

• strategy

  When set to parallel(default) terragrunt run-all apply will be executed in provided path. And terragrunt will execute multiple plans in parallel accordint to parallelism settings. Plan will be applied even if there is no changes for particular module.

  When set to sequential terragrunt will change into each module directory individually and execute terragrunt run-all apply and only when there are changes in the plan. So it will skip modules without changes and apply changes one by one.

  • Type: string
  • Optional
  • Default: parallel

• create_cache_folder_in_workspace

  Set to true to create a cache folder in workspace. It can be reused in other steps, jobs and workflows. By default it created in /tmp folder inside docker container and not available outside.

  • Type: boolean
  • Optional
  • Default: false

• cache_folder

  Specify custom name for the cache folder which will be created in github workspace. Two additional folders will be created inside cache_folder: tf_plugin_cache_folder and tg_cache_folder

  • Type: string
  • Optional
  • Default: .terragrunt-cache

• use_tf_plugin_cache_folder

  If set to true, the varibale TF_PLUGIN_CACHE_DIR will be enabled. Sometimes there can be problems when using these variable in Terragrunt

  • Type: boolean
  • Optional
  • Default: false

• tf_plugin_cache_folder

  Specify custom name for the tf_plugin_cache_folder folder which will be created inside cache_folder. Variable TF_PLUGIN_CACHE_DIR will be set to ${GITHUB_WORKSPACE}/${cache_folder}/${tf_plugin_cache_folder}. Only applicable if use_tf_plugin_cache_folder is set to true

  • Type: string
  • Optional
  • Default: tf-plugin-cache

• tg_cache_folder

  Specify custom name for the tg_cache_folder folder which will be created inside cache_folder. Terragrunt commands will be executed with option --terragrunt-download-dir ${GITHUB_WORKSPACE}/${cache_folder}/${tg_cache_folder}

  • Type: string
  • Optional
  • Default: tg-cache

Environment Variables

• GITHUB_TOKEN

  The GitHub authorization token to use to fetch an approved plans from a PR. This must belong to the same user/app as the token used by the terragrunt-plan-all action. The token provided by GitHub Actions can be used - it can be passed by using the ${{ secrets.GITHUB_TOKEN }} expression, e.g.

  env:
    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

  The token provided by GitHub Actions has default permissions at GitHub's whim. You can see what it is for your repo under the repo settings.

  The minimum permissions are pull-requests: write. It will also likely need contents: read so the job can checkout the repo.

  You can also use any other App token that has pull-requests: write permission.

  You can use a fine-grained Personal Access Token which has repository permissions:

  • Read access to metadata
  • Read and Write access to pull requests

  You can also use a classic Personal Access Token which has the repo scope.

  The GitHub user or app that owns the token will be the PR comment author.

  • Type: string
  • Optional

• TERRAFORM_ACTIONS_GITHUB_TOKEN

  When this is set it is used instead of GITHUB_TOKEN, with the same behaviour. The GitHub Terraform provider also uses the GITHUB_TOKEN environment variable, so this can be used to make the github actions and the Terraform provider use different tokens.

  • Type: string
  • Optional

Workflow events

When adding the plan to a PR comment (add_github_comment is set to true/changes-only), the workflow can be triggered by the following events:

• pull_request
• pull_request_review_comment
• pull_request_target
• pull_request_review
• issue_comment, if the comment is on a PR (see below)
• push, if the pushed commit came from a PR (see below)
• repository_dispatch, if the client payload includes the pull_request url (see below)

When auto_approve is set to true, the workflow can be triggered by any event.

issue_comment

This event triggers workflows when a comment is made in a Issue, as well as a Pull Request. Since running the action will only work in the context of a PR, the workflow should check that the comment is on a PR before running.

Also take care to checkout the PR ref.

jobs:
  plan:
    if: ${{ github.event.issue.pull_request }}
    runs-on: ubuntu-latest
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - name: Checkout
        uses: actions/checkout@v3
        with:
          ref: refs/pull/${{ github.event.issue.number }}/merge

      - name: terragrung plan
        uses: wayofdev/[email protected]
        with:
          path: my-terraform-config

push

The pushed commit must have come from a Pull Request. Typically this is used to trigger a workflow that runs on the main branch after a PR has been merged.

repository_dispatch

This event can be used to trigger a workflow from another workflow. The client payload must include the pull_request api url of where the plan PR comment should be added.

A minimal example payload looks like:

{
  "pull_request": {
    "url": "https://api.github.com/repos/wayofdev/gh-actions-terragrunt/pulls/1"
  }
}

Example usage

Apply PR approved plans

This example workflow runs for every push to main. If the commit came from a PR that has been merged, applies the plan from the PR.

name: Apply

on:
  push:
    branches:
      - main

permissions:
  contents: read
  pull-requests: write

jobs:
  apply:
    runs-on: ubuntu-latest
    name: Apply approved plan
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: terraform apply
        uses: wayofdev/gh-action-terragrunt-apply@v1
        with:
          path: my-terraform-config

Always apply changes

This example workflow runs for every push to main. Changes are planned and applied.

name: Apply

on:
  push:
    branches:
      - main

jobs:
  apply:
    runs-on: ubuntu-latest
    name: Apply Terraform
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: terraform apply
        uses: dflook/terraform-apply@v1
        with:
          path: my-terraform-config
          auto_approve: true