Hooks and Tests

Part of the Helm course

Some work does not fit neatly into "render a manifest and apply it." A database schema needs to be migrated before the new application pods start reading from it, or an admin account needs to exist right after a fresh install finishes, or you want an automatic smoke test that pokes the service and confirms it actually answers before you walk away from a deploy.

There is no kind: Hook anywhere in Kubernetes or in Helm. A hook is an ordinary Kubernetes resource, most often a Job or a Pod, that carries a particular annotation Helm watches for. Here is one from this lesson's workspace, templates/pre-install-job.yaml: