Chapter 9. Building and deploying functions on the cluster

Procedure

1. Create a function:

   $ kn func create <function_name> -l <runtime>

2. Implement the business logic of your function. Then, use Git to commit and push the changes.

3. Deploy your function:

   $ kn func deploy --remote

   If you are not logged into the container registry referenced in your function configuration, you are prompted to provide credentials for the remote container registry that hosts the function image:

   Example output and prompts

   🕕 Creating Pipeline resources
   Please provide credentials for image registry used by Pipeline.
   ? Server: https://index.docker.io/v1/
   ? Username: my-repo
   ? Password: ********
      Function deployed at URL: http://test-function.default.svc.cluster.local

4. To update your function, commit and push new changes by using Git, then run the kn func deploy --remote command again.

5. Optional. You can configure your function to be built on the cluster after every Git push by using pipelines-as-code:

   1. Generate the Tekton Pipelines and PipelineRuns configuration for your function:

      $ kn func config git set

      Apart from generating configuration files, this command connects to the cluster and validates that the pipeline is installed. By using the token, it also creates, on behalf of the user, a webhook on the function repository. That webhook triggers the pipeline on the cluster every time changes are pushed to the repository.

      You need to have a valid GitHub personal access token with the repository access to use this command.

   2. Commit and push the generated .tekton/pipeline.yaml and .tekton/pipeline-run.yaml files:

      $ git add .tekton/pipeline.yaml .tekton/pipeline-run.yaml
      $ git commit -m 'Add the Pipelines and PipelineRuns configuration'
      $ git push

   3. After you make a change to your function, commit and push it. The function is rebuilt automatically by using the created pipeline.