A GitHub Action to get a list of affected atmos stacks for a pull request
Introduction
This is a GitHub Action to get a list of affected atmos stacks for a pull request. It optionally installs
atmos and jq and runs atmos describe affected to get the list of affected stacks. It provides the
raw list of affected stacks as an output as well as a matrix that can be used further in GitHub action jobs.
Usage
Config
Important
Please note! This GitHub Action only works with atmos >= 1.99.0.
If you are using atmos >= 1.80.0, < 1.99.0 please use v5 version of this action.
If you are using atmos >= 1.63.0, < 1.80.0 please use v3 or v4 version of this action.
If you are using atmos < 1.63.0 please use v2 version of this action.
The action expects the atmos configuration file atmos.yaml to be present in the repository.
The action supports AWS and Azure to store Terraform plan files.
You can read more about plan storage in the cloudposse/github-action-terraform-plan-storage documentation.
Depends of cloud provider the following fields should be set in the atmos.yaml:
AWS
The config should have the following structure:
integrations: github: gitops: opentofu-version: 1.7.3 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 # Set `apply` empty if you don't want to assume IAM role before terraform apply apply: arn:aws:iam::yyyyyyyyyyyy:role/cptest-core-gbl-identity-gitops matrix: sort-by: .stack_slug group-by: .stack_slug | split("-") | [.[0], .[2]] | join("-")
Azure
The config should have the following structure:
integrations: github: gitops: opentofu-version: 1.7.3 terraform-version: 1.5.2 infracost-enabled: false artifact-storage: plan-repository-type: azureblob blob-account-name: tfplans blob-container-name: plans metadata-repository-type: cosmos cosmos-container-name: terraform-plan-storage cosmos-database-name: terraform-plan-storage cosmos-endpoint: "https://my-cosmo-account.documents.azure.com:443/" # We remove the `role` section as it is AWS specific matrix: sort-by: .stack_slug group-by: .stack_slug | split("-") | [.[0], .[2]] | join("-")
Stack level configuration
Important
Wherever it is possible to specify integration.github.gitops on stack level
it is required to define default values in atmos.yaml
It is possible to override integration settings on a stack level by defining settings.integrations.
components: terraform: foobar: settings: integrations: github: gitops: artifact-storage: bucket: cptest-plat-ue2-auto-gitops table: cptest-plat-ue2-auto-gitops-plan-storage role: arn:aws:iam::xxxxxxxxxxxx:role/cptest-plat-ue2-auto-gitops-gha role: # Set `plan` empty if you don't want to assume IAM role before terraform plan plan: arn:aws:iam::yyyyyyyyyyyy:role/cptest-plat-gbl-identity-gitops apply: arn:aws:iam::yyyyyyyyyyyy:role/cptest-plat-gbl-identity-gitops
Support OpenTofu
This action supports OpenTofu.
Important
Please note! OpenTofu supported by Atmos >= 1.73.0.
For details read
To enable OpenTofu add the following settings to atmos.yaml
- Set the
opentofu-versionin theatmos.yamlto the desired version - Set
components.terraform.commandtotofu
Example
components: terraform: command: tofu ... integrations: github: gitops: opentofu-version: 1.7.3 ...
Workflow example
name: Pull Request on: pull_request: branches: [ 'main' ] types: [opened, synchronize, reopened, closed, labeled, unlabeled] jobs: atmos-affected: runs-on: ubuntu-latest steps: - id: affected uses: cloudposse/github-action-atmos-affected-stacks@v6 with: atmos-config-path: ./rootfs/usr/local/etc/atmos/ atmos-version: 1.99.0 nested-matrices-count: 1 outputs: matrix: ${{ steps.affected.outputs.matrix }} has-affected-stacks: ${{ steps.affected.outputs.has-affected-stacks }} # This job is an example how to use the affected stacks with the matrix strategy atmos-plan: needs: ["atmos-affected"] if: ${{ needs.atmos-affected.outputs.has-affected-stacks == 'true' }} name: Plan ${{ matrix.stack_slug }} runs-on: ubuntu-latest strategy: max-parallel: 10 fail-fast: false # Don't fail fast to avoid locking TF State matrix: ${{ fromJson(needs.atmos-affected.outputs.matrix) }} ## Avoid running the same stack in parallel mode (from different workflows) concurrency: group: ${{ matrix.stack_slug }} cancel-in-progress: false steps: - name: Plan Atmos Component uses: cloudposse/github-action-atmos-terraform-plan@v4 with: component: ${{ matrix.component }} stack: ${{ matrix.stack }} atmos-config-path: ./rootfs/usr/local/etc/atmos/ atmos-version: 1.99.0
Migrating from v5 to v6
The notable changes in v6 are:
v6works only withatmos >= 1.99.0v6allow to skip internal checkout withskip-checkoutinput
The only required migration step is updating atmos version to >= 1.80.0
Migrating from v4 to v5
The notable changes in v5 are:
v5works only withatmos >= 1.80.0v5supports atmos templating
The only required migration step is updating atmos version to >= 1.80.0
Migrating from v3 to v4
The notable changes in v4 are:
v4perform aws authentication assumingintegrations.github.gitops.role.planIAM role
No special migration steps required
Migrating from v2 to v3
The notable changes in v3 are:
v3works only withatmos >= 1.63.0v3dropsinstall-terraforminput because terraform is not required for affected stacks callv3dropsatmos-gitops-config-pathinput and the./.github/config/atmos-gitops.yamlconfig file. Now you have to use GitHub Actions environment variables to specify the location of theatmos.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 v2 to v3, 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
- id: affected uses: cloudposse/github-action-atmos-affected-stacks@v3 with: atmos-config-path: ./rootfs/usr/local/etc/atmos/ atmos-version: 1.63.0
This corresponds to the v2 configuration (deprecated) below.
The v2 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 v2 GitHub Action Workflow looked like this.
.github/workflows/main.yaml
- id: affected uses: cloudposse/github-action-atmos-affected-stacks@v2 with: atmos-gitops-config-path: ./.github/config/atmos-gitops.yaml
Migrating from v1 to v2
v2 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-affected-stacks 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 v2 as in v1 you should create config ./.github/config/atmos-gitops.yaml with the same variables as in v1 inputs.
- name: Determine Affected Stacks uses: cloudposse/github-action-atmos-affected-stacks@v2 id: affected with: atmos-gitops-config-path: ./.github/config/atmos-gitops.yaml nested-matrices-count: 1
Which would produce the same behavior as in v1, doing this:
- name: Determine Affected Stacks uses: cloudposse/github-action-atmos-affected-stacks@v1 id: affected with: 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
Inputs
| Name | Description | Default | Required |
|---|---|---|---|
| atmos-config-path | The path to the atmos.yaml file | N/A | true |
| atmos-include-dependents | Whether to include dependents of affected stacks in the output | false | false |
| atmos-include-settings | Include the settings section for each affected component |
false | false |
| atmos-include-spacelift-admin-stacks | Whether to include the Spacelift admin stacks of affected stacks in the output | false | false |
| atmos-pro-base-url | The base URL of Atmos Pro | https://atmos-pro.com | false |
| atmos-pro-token | The API token to allow Atmos Pro to upload affected stacks | false | |
| atmos-pro-upload | Whether to upload affected stacks directly to Atmos Pro | false | false |
| atmos-stack | The stack to operate on | false | |
| atmos-version | The version of atmos to install | >= 1.99.0 | false |
| base-ref | The base ref to checkout. If not provided, the head default branch is used. | N/A | false |
| default-branch | The default branch to use for the base ref. | ${{ github.event.repository.default_branch }} | false |
| head-ref | The head ref to checkout. If not provided, the head default branch is used. | ${{ github.sha }} | false |
| identity | Atmos auth identity | false | |
| install-atmos | Whether to install atmos | true | false |
| install-jq | Whether to install jq | false | false |
| jq-force | Whether to force the installation of jq | true | false |
| jq-version | The version of jq to install if install-jq is true | 1.7 | false |
| nested-matrices-count | Number of nested matrices that should be returned as the output (from 1 to 3) | 2 | false |
| process-functions | Whether to process atmos functions | true | false |
| process-templates | Whether to process atmos templates | true | false |
| skip-atmos-functions | Skip all Atmos functions such as terraform.output | false | false |
| skip-checkout | Disable actions/checkout for head-ref and base-ref. Useful for when the checkout happens in a previous step and file are modified outside of git through other actions | false | false |
Outputs
| Name | Description |
|---|---|
| affected | The affected stacks |
| has-affected-stacks | Whether there are affected stacks |
| matrix | The affected stacks as matrix structure suitable for extending matrix size workaround (see README) |
Related Projects
Check out these related projects.
References
For additional context, refer to some of these links.
β¨ Contributing
This project is under active development, and we encourage contributions from our community.
Many thanks to our outstanding contributors:
For π bug reports & feature requests, please use the issue tracker.
In general, PRs are welcome. We follow the typical "fork-and-pull" Git workflow.
- Review our Code of Conduct and Contributor Guidelines.
- Fork the repo on GitHub
- Clone the project to your own machine
- Commit changes to your own branch
- Push your work back up to your fork
- Submit a Pull Request so that we can review your changes
NOTE: Be sure to merge the latest changes from "upstream" before making a pull request!
π Slack Community
Join our Open Source Community on Slack. It's FREE for everyone! Our "SweetOps" community is where you get to talk with others who share a similar vision for how to rollout and manage infrastructure. This is the best place to talk shop, ask questions, solicit feedback, and work together as a community to build totally sweet infrastructure.
π° Newsletter
Sign up for our newsletter and join 3,000+ DevOps engineers, CTOs, and founders who get insider access to the latest DevOps trends, so you can always stay in the know. Dropped straight into your Inbox every week β and usually a 5-minute read.
Join us every Wednesday via Zoom for your weekly dose of insider DevOps trends, AWS news and Terraform insights, all sourced from our SweetOps community, plus a live Q&A that you canβt find anywhere else. It's FREE for everyone!
License
Preamble to the Apache License, Version 2.0
Complete license is available in the LICENSE file.
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
https://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
Trademarks
All other trademarks referenced herein are the property of their respective owners.
Copyright Β© 2017-2026 Cloud Posse, LLC

