Chapter 9. Building and deploying functions on the cluster

Procedure

1. Create the following resources:

   1. Create the s2i Tekton task to be able to use Source-to-Image in the pipeline:

      $ oc apply -f https://raw.githubusercontent.com/openshift-knative/kn-plugin-func/serverless-1.29.0/pkg/pipelines/resources/tekton/task/func-s2i/0.1/func-s2i.yaml

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   2. Create the kn func deploy Tekton task to be able to deploy the function in the pipeline:

      $ oc apply -f https://raw.githubusercontent.com/openshift-knative/kn-plugin-func/serverless-1.29.0/pkg/pipelines/resources/tekton/task/func-deploy/0.1/func-deploy.yaml

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2. Create a function:

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

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

4. Deploy your function:

   $ kn func deploy --remote

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   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

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

6. 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

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      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

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