DevOps: CAP CI/CD with GitHub Actions

cds add mta

npm install -g mbt
mbt build -p cf

cf login
cf deploy mta_archives/cap-github-actions_1.0.0.mtar

Build and Deploy Using GitHub Actions

Now that you a simple CAP app and you can build and deploy it from a local machine, let’s see how to do the same with GitHub Actions.

Encrypted Secrets

As you don’t want to expose the details of your Cloud Foundry account (organization, space and so on) you first need to create some encrypted secrets in GitHub. This can be done in the repository Settings on GitHub:

Create GitHub Workflow

Now you need to create a GitHub Workflow to build and deploy the project to Cloud Foundry when an event occurs (i.e push to master branch for instance). You don’t have to build everything from scratch and you can just reuse an existing action to deploy to CF.

To create a new Workflow, just click on the Actions tab and then on the setup a workflow yourself link:

This will open an editor where we can define our own workflow. Replace the content of the editor with the following code:

# Build Multitarget Application & Deploy it to Cloud Foundry
name: Build MTA & Deploy it to CF

# Controls when the action will run. Triggers the workflow on push or pull request
# events but only for the master branch
on:
  push:
    branches: [ master ]

# A workflow run is made up of one or more jobs that can run sequentially or in parallel
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Use Node.js
      uses: actions/setup-node@v1
      with:
        node-version: 12
    - name: Install MTA Build Tool
      run: npm install -g mbt
    # Do not generate package-lock.json
    # See https://blogs.sap.com/2020/07/07/escaping-eintegrity-hell/
    - name: Disable package-lock.json
      run: npm config set package-lock false
    - name: Build MTA
      run: mbt build -p cf
    - name: Upload Artifact
      uses: actions/upload-artifact@master	
      with:	
        name: mta
        path: ./mta_archives/cap-github-actions_1.0.0.mtar
        
  deploy:
     needs: build
     runs-on: ubuntu-latest
     steps:
       - name: Download Artifact
         uses: actions/download-artifact@master
         with:
           name: mta
           path: ./
       - name: Deploy to Cloud Foundry
         uses: guerric-p/cf-cli-action@master
         with:
           cf_api: ${{ secrets.CF_API }}
           cf_username: ${{ secrets.CF_USERNAME }}
           cf_password: ${{ secrets.CF_PASSWORD }}
           cf_org: ${{ secrets.CF_ORG }}
           cf_space: ${{ secrets.CF_SPACE }}
           command: deploy ./cap-github-actions_1.0.0.mtar -f

This simple workflow contains 2 jobs, one to build the app and one to deploy the MTA to CF. There are multiple steps in each job to replicate everything you did locally using the GitHub infrastructure when code is pushed to the master branch.

Note:

There’s a temporary fix in the workflow to prevent EINTEGRITY errors. I believe this is due to the fact that SCP has not switched yet to the public npm repository (please read the following post from DJ Adams).

Test the Workflow

Now you just need to push to the master branch to trigger the new workflow and to automatically build & deploy the application.

You should see the status of the workflow on GitHub:

and you can also navigate to the details:

Closing

This post just gives you the basics to get started, there are many things you can do with GitHub Actions:

• trigger workflow with various events: push, issue creation, pull request creation etc.
• use your own self-hosted runners if the provided runners don’t meet your needs
• re-use workflows and actions provided by the community
• …

If you have any experience with GitHub Actions or other CI/CD solutions please do share your thoughts!