Framework

To set up the automation we need to:

1. Push your repository.
2. Set up pipeline credentials.
3. Add the pipeline file.
4. Follow the GitOps process.

1. Create the remote repository

   Create a new repository and give it a descriptive name. For example infrastructure-automation.

   

2. Push the repository

   Follow option two from Github's instructions to push your existing repository.

   

1. First create a new branch to work in.

   git checkout -b ghactions
   

2. Add the pipeline as .github/workflows/main.yaml.

   mkdir -p .github/workflows
   cat > .github/workflows/main.yaml <<'EOF'
   name: deploy
   on:
     push:
       branches:
       - "*"  # run for branches
       tags:
       - "*"  # run for tags
   jobs:
     deploy:
       runs-on: ubuntu-latest
       env:
         TF_IN_AUTOMATION: true
         KBST_DOCKER_ARGS: --rm -v ${{ github.workspace }}:/infra
         KBST_DOCKER_IMAGE: kbst:${{ github.sha }}
       steps:
       - uses: actions/checkout@v1
       #
       #
       # Build image
       - name: Build image
         env:
           DOCKER_BUILDKIT: 1
         run: docker build -t $KBST_DOCKER_IMAGE .
       #
       #
       # Authenticate cloud providers
       - name: Authenticate providers
         env:
           KBST_AUTH_AWS: ${{ secrets.KBST_AUTH_AWS }}
           KBST_AUTH_AZ: ${{ secrets.KBST_AUTH_AZ }}
           KBST_AUTH_GCLOUD: ${{ secrets.KBST_AUTH_GCLOUD }}
         run: |
           docker run \
               $KBST_DOCKER_ARGS \
               -e KBST_AUTH_AWS \
               -e KBST_AUTH_AZ \
               -e KBST_AUTH_GCLOUD \
               $KBST_DOCKER_IMAGE
       #
       #
       # Terraform init
       - name: Terraform init
         run: |
           docker run \
               $KBST_DOCKER_ARGS \
               $KBST_DOCKER_IMAGE \
             terraform init
       #
       #
       # Select ops or apps workspace
       - name: Select ops workspace
         if: startsWith(github.ref, 'refs/tags/apps-deploy-') == false
         run: |
           docker run \
               $KBST_DOCKER_ARGS \
               $KBST_DOCKER_IMAGE \
             terraform workspace select ops
       - name: Select apps workspace
         if: startsWith(github.ref, 'refs/tags/apps-deploy-')
         run: |
           docker run \
               $KBST_DOCKER_ARGS \
               $KBST_DOCKER_IMAGE \
             terraform workspace select apps
       #
       #
       # Terraform plan against current workspace
       - name: Terraform plan
         run: |
           docker run \
               $KBST_DOCKER_ARGS \
               $KBST_DOCKER_IMAGE \
             terraform plan --out=tfplan --input=false
       #
       #
       # Terraform apply against current workspace
       # for master branch or apps-deploy tag
       - name: Terraform apply
         if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/apps-deploy-')
         run: |
           docker run \
               $KBST_DOCKER_ARGS \
               $KBST_DOCKER_IMAGE \
             terraform apply --input=false tfplan
       #
       #
       # Terraform plan against apps workspace
       # after applying to ops,
       # run plan against apps
       - name: Terraform plan
         if: github.ref == 'refs/heads/master'
         run: |
           docker run \
               $KBST_DOCKER_ARGS \
               $KBST_DOCKER_IMAGE \
             terraform workspace select apps
           docker run \
               $KBST_DOCKER_ARGS \
               $KBST_DOCKER_IMAGE \
             terraform plan --out=tfplan --input=false
   EOF
   

1. Add, commit and push the pipeline.

   git add .
   git commit -m "Add Github Actions pipeline"
   git push origin ghactions
   

2. Open a pull request.

   

3. Check the pipeline run.

   The pipeline run for the ghactions branch does not apply changes. It only provides the output of terraform plan against the ops workspace to determine what changes will be applied once merged.

   

   Since we already bootstrapped the clusters, the pipeline at this point has no planned changes.

4. Merge the pull request to apply changes to ops.

   Merge the pull request into master. The pipeline applies changes against the ops workspace on every commit to master.

   

5. Finally, set a tag to apply changes to apps.

   # checkout the master branch
   git checkout master
   # pull changes from origin
   git pull
   # tag the merge commit
   git tag apps-deploy-0
   # push the tag to origin to trigger the pipeline
   git push origin apps-deploy-0
   

   

Compare the output of the three pipeline runs. You will see how when triggered from a feature branch, triggered from the master branch or triggered from a tag the pipeline behaves differently.

For more details refer to the GitOps Flow making changes section.

To recap:

• You bootstrapped a local repository.
• Created prerequisites like the Terraform remote state and the identity for the automation runs.
• You provisioned both the ops and apps infrastructure environments.
• Setup DNS and Ingress to be able to expose workloads.
• You linked your repository to trigger automated pipeline runs.

Congratulations, you now have a fully automated GitOps infrastructure.