Tutorial bugs

[ncskier]

I ran into a couple of issues going through this tutorial.

1. workingDir instead of workingdir

apply_manifest_task.yaml has a typo:

      workingdir: /workspace/source

should be

      workingDir: /workspace/source

2. run with pipeline ServiceAccount

The tutorial does not specify a ServiceAccount when creating the PipelineRun. So, it fails when pushing images to the internal registry:

tkn pipeline start build-and-deploy

Instead, we should run the PipelineRun under the pipeline ServiceAccount

tkn pipeline start build-and-deploy --serviceaccount pipeline