This commit adds a new flag to the experimental feature of generating a CRD chart for charts that need to be able to assume the ownership of any existing CRDs within a cluster. It also modifies the existing `prepare-crd` script to use template files stored in the `./scripts/chart-templates/` directory instead of utilizing numerous `cat` commands in order to achieve the same result.
Feature charts with this flag enabled will differ from the normal CRD chart in the following ways:
- Instead of having CRDs from `crd/` in `templates/`, they will be relocated to `crd-manifest/`.
- On render, the CRDs in `crd-manifest` are placed into a ConfigMap that will be deployed on the cluster.
- On install / upgrade / rollback, a pre-install / pre-upgrade / pre-rollback hook Job that does a `kubectl apply -f` on the manifest within the crd-manifest ConfigMap (with appropriate RBAC credentials via a ServiceAccount, CRB, and ClusterRole) will install the CRDs onto the cluster.
- On uninstall, a delete hook Job does a `kubectl delete -f` on the manifest within the crd-manifest ConfigMap (with the same RBAC credentials) to remove the CRDs from the cluster.
At the moment, this will only be used by the `rancher-monitoring` chart.
Related Issue: https://github.com/rancher/rancher/issues/28326
Before, the logic for reverting a CRD chart was located in `generate-patch` since it was the only script that required these changes. Now that the same logic is required on a `make clean` in order to support reverting just the generateCRDChart changes from local charts, this commit moves that logic out to its own script `clean-crds`.
Based on discussion in https://github.com/rancher/charts/pull/607#discussion_r483288658.
Arvind Iyengar