GitHub Action: atmos-terraform-apply

This Github Action is used to run Terraform apply for a single, Atmos-supported component with a saved planfile in S3 and DynamoDB.

Introduction

This Github Action is used to run Terraform apply for a single, Atmos-supported component with a saved planfile in S3 and DynamoDB.

Before running this action, first create and store a planfile with the companion action, github-action-atmos-terraform-plan.

For more, see Atmos GitHub Action Integrations

Usage

Prerequisites

This GitHub Action requires AWS access for two different purposes. This action will attempt to first pull a Terraform planfile from a S3 Bucket with metadata in a DynamoDB table with one role. Then the action will run terraform apply against that component with another role. We recommend configuring OpenID Connect with AWS to allow GitHub to assume roles in AWS and then deploying both a Terraform Apply role and a Terraform State role. For Cloud Posse documentation on setting up GitHub OIDC, see our github-oidc-provider component.

In order to retrieve Terraform Plan Files (not to be confused with Terraform State files, e.g. tfstate), we configure an S3 Bucket to store plan files and a DynamoDB table to track plan metadata. Both need to be deployed before running this action. For more on setting up those components, see the gitops component. This action will then use the github-action-terraform-plan-storage action to update these resources.

Config

The action expects the atmos configuration file atmos.yaml to be present in the repository. The config should have the following structure:

integrations:
  github:
    gitops:
      terraform-version: 1.5.2
      infracost-enabled: false
      artifact-storage:
        region: us-east-2
        bucket: cptest-core-ue2-auto-gitops
        table: cptest-core-ue2-auto-gitops-plan-storage
        role: arn:aws:iam::xxxxxxxxxxxx:role/cptest-core-ue2-auto-gitops-gha
      role:
        plan: arn:aws:iam::yyyyyyyyyyyy:role/cptest-core-gbl-identity-gitops
        apply: arn:aws:iam::yyyyyyyyyyyy:role/cptest-core-gbl-identity-gitops
      matrix:
        sort-by: .stack_slug
        group-by: .stack_slug | split("-") | [.[0], .[2]] | join("-")

[!IMPORTANT] Please note! This GitHub Action only works with atmos >= 1.63.0. If you are using atmos < 1.63.0 please use v1 version of this action.

Workflow example

In this example, the action is triggered when certain events occur, such as a manual workflow dispatch or the opening, synchronization, or reopening of a pull request, specifically on the main branch. It specifies specific permissions related to assuming roles in AWS. Within the "apply" job, the "component" and "stack" are hardcoded (foobar and plat-ue2-sandbox). In practice, these are usually derived from another action.

[!TIP] We recommend combining this action with the affected-stacks GitHub Action inside a matrix to plan all affected stacks in parallel.

  name: github-action-atmos-terraform-apply

  on:
    workflow_dispatch:
    pull_request:
      types:
        - closed
      branches:
        - main

  # These permissions are required for GitHub to assume roles in AWS
  permissions:
    id-token: write
    contents: read

  jobs:
    apply:
      runs-on: ubuntu-latest
      steps:
        - name: github-action-atmos-terraform-apply
          uses: cloudposse/github-action-atmos-terraform-apply@v2
          with:
            component: "foobar"
            stack: "plat-ue2-sandbox"
            atmos-config-path: ./rootfs/usr/local/etc/atmos/

Migrating from v1 to v2

The notable changes in v2 are:

• v2 works only with atmos >= 1.63.0
• v2 drops install-terraform input because terraform is not required for affected stacks call
• v2 drops atmos-gitops-config-path input and the ./.github/config/atmos-gitops.yaml config file. Now you have to use GitHub Actions environment variables to specify the location of the atmos.yaml.

The following configuration fields now moved to GitHub action inputs with the same names

name
atmos-version
atmos-config-path

The following configuration fields moved to the atmos.yaml configuration file.

name	YAML path in atmos.yaml
aws-region	integrations.github.gitops.artifact-storage.region
terraform-state-bucket	integrations.github.gitops.artifact-storage.bucket
terraform-state-table	integrations.github.gitops.artifact-storage.table
terraform-state-role	integrations.github.gitops.artifact-storage.role
terraform-plan-role	integrations.github.gitops.role.plan
terraform-apply-role	integrations.github.gitops.role.apply
terraform-version	integrations.github.gitops.terraform-version
enable-infracost	integrations.github.gitops.infracost-enabled
sort-by	integrations.github.gitops.matrix.sort-by
group-by	integrations.github.gitops.matrix.group-by

For example, to migrate from v1 to v2, you should have something similar to the following in your atmos.yaml:

./.github/config/atmos.yaml

# ... your existing configuration

integrations:
  github:
    gitops:
      terraform-version: 1.5.2
      infracost-enabled: false
      artifact-storage:
        region: us-east-2
        bucket: cptest-core-ue2-auto-gitops
        table: cptest-core-ue2-auto-gitops-plan-storage
        role: arn:aws:iam::xxxxxxxxxxxx:role/cptest-core-ue2-auto-gitops-gha
      role:
        plan: arn:aws:iam::yyyyyyyyyyyy:role/cptest-core-gbl-identity-gitops
        apply: arn:aws:iam::yyyyyyyyyyyy:role/cptest-core-gbl-identity-gitops
      matrix:
        sort-by: .stack_slug
        group-by: .stack_slug | split("-") | [.[0], .[2]] | join("-")

.github/workflows/main.yaml

  - name: github-action-atmos-terraform-apply
    uses: cloudposse/github-action-atmos-terraform-apply@v2
    with:
      component: "foobar"
      stack: "plat-ue2-sandbox"
      atmos-config-path: ./rootfs/usr/local/etc/atmos/
      atmos-version: 1.63.0

This corresponds to the v1 configuration (deprecated) below.

The v1 configuration file ./.github/config/atmos-gitops.yaml looked like this:

atmos-version: 1.45.3
atmos-config-path: ./rootfs/usr/local/etc/atmos/
terraform-state-bucket: cptest-core-ue2-auto-gitops
terraform-state-table: cptest-core-ue2-auto-gitops
terraform-state-role: arn:aws:iam::xxxxxxxxxxxx:role/cptest-core-ue2-auto-gitops-gha
terraform-plan-role: arn:aws:iam::yyyyyyyyyyyy:role/cptest-core-gbl-identity-gitops
terraform-apply-role: arn:aws:iam::yyyyyyyyyyyy:role/cptest-core-gbl-identity-gitops
terraform-version: 1.5.2
aws-region: us-east-2
enable-infracost: false
sort-by: .stack_slug
group-by: .stack_slug | split("-") | [.[0], .[2]] | join("-")  

And the v1 GitHub Action Workflow looked like this.

.github/workflows/main.yaml

  - name: github-action-atmos-terraform-apply
    uses: cloudposse/github-action-atmos-terraform-apply@v1
    with:
      component: "foobar"
      stack: "plat-ue2-sandbox"
      atmos-gitops-config-path: ./.github/config/atmos-gitops.yaml

Migrating from v0 to v1

1. v1 drops the component-path variable and instead fetches if directly from the atmos.yaml file automatically. Simply remove the component-path argument from your invocations of the cloudposse/github-action-atmos-terraform-apply action.
2. v1 moves most of the inputs to the Atmos GitOps config path ./.github/config/atmos-gitops.yaml. Simply create this file, transfer your settings to it, then remove the corresponding arguments from your invocations of the cloudposse/github-action-atmos-terraform-apply action.

name
atmos-version
atmos-config-path
terraform-state-bucket
terraform-state-table
terraform-state-role
terraform-plan-role
terraform-apply-role
terraform-version
aws-region
enable-infracost

If you want the same behavior in v1 as in v0 you should create config ./.github/config/atmos-gitops.yaml with the same variables as in v0 inputs.

- name: github-action-atmos-terraform-apply
  uses: cloudposse/github-action-atmos-terraform-apply@v1
  with:
    atmos-gitops-config-path: ./.github/config/atmos-gitops.yaml
    component: "foobar"
    stack: "plat-ue2-sandbox"

Which would produce the same behavior as in v0, doing this:

- name: github-action-atmos-terraform-apply
  uses: cloudposse/github-action-atmos-terraform-apply@v0
  with:
    component: "foobar"
    stack: "plat-ue2-sandbox"
    component-path: "components/terraform/s3-bucket"
    terraform-apply-role: "arn:aws:iam::111111111111:role/acme-core-gbl-identity-gitops"
    terraform-state-bucket: "acme-core-ue2-auto-gitops"
    terraform-state-role: "arn:aws:iam::999999999999:role/acme-core-ue2-auto-gitops-gha"
    terraform-state-table: "acme-core-ue2-auto-gitops"
    aws-region: "us-east-2"

Inputs

Name	Description	Default	Required
atmos-config-path	The path to the atmos.yaml file	N/A	true
atmos-version	The version of atmos to install	>= 1.63.0	false
branding-logo-image	Branding logo image url	https://cloudposse.com/logo-300x69.svg	false
branding-logo-url	Branding logo url	https://cloudposse.com/	false
component	The name of the component to apply.	N/A	true
debug	Enable action debug mode. Default: 'false'	false	false
infracost-api-key	Infracost API key	N/A	false
sha	Commit SHA to apply. Default: github.sha	${{ github.event.pull_request.head.sha }}	true
stack	The stack name for the given component.	N/A	true
token	Used to pull node distributions for Atmos from Cloud Posse's GitHub repository. Since there's a default, this is typically not supplied by the user. When running this action on github.com, the default value is sufficient. When running on GHES, you can pass a personal access token for github.com if you are experiencing rate limiting.	${{ github.server_url == 'https://github.com' && github.token || '' }}	false

Outputs

Name	Description
status	Apply Status. Either 'succeeded' or 'failed'