airgap: enable disconnected installation for Trustee operator

[beraldoleal]

To install Trustee in disconnected environments, users need an ImageSetConfiguration for oc-mirror and all operand images listed in the bundle. This PR adds both.

Tested locally with --dry-run. Planning to validate on a real disconnected cluster once the first round of review is in place.

[lmilleri]

Should the ocp 4.21 mirror be added as well?

[beraldoleal]

Thank you @lmilleri , done.

[lmilleri]

lgtm

[lmilleri]

@beraldoleal on second thought, I'm not completely sure we should have multiple yaml files, one per ocp version.

What about having a single file named imageset-config.yaml.in:

kind: ImageSetConfiguration
apiVersion: mirror.openshift.io/v1alpha2
storageConfig:
  registry:
    # URL of your internal registry where oc-mirror will store its metadata
    # and push the mirrored images.
    imageURL: ${REGISTRY}/mirror/oc-mirror-metadata
    skipTLS: false
mirror:
  operators:
  - # Red Hat's official OLM catalog index for OCP 4.21.
    # oc-mirror will automatically mirror the catalog index, the operator
    # bundle, and all images listed as relatedImages in the bundle.
    catalog: registry.redhat.io/redhat/redhat-operator-index:v${OCP_VERSION}
    packages:
    - name: trustee-operator
      channels:
      - name: stable

and provide instructions for generating the yaml manifest like:

export REGISTRY=<user-registry>
export OCP_VERSION=4.21
envsubst < imageset-config.yaml.in > imageset-config.yaml

This way we won't have to create a new file for the next ocp releases

[beraldoleal]

Hey @lmilleri, I´'m not sure a template would work well here... the content can change between versions beyond just the version number, and the .yaml.in isn't valid YAML so tooling can't validate or parse it. I also see this being nudged by Konflux for digest bumps, which expects real YAML files.

So, what about if we keep it as-is for now and revisit if needed? wdyt?

[lmilleri]

ok fine with me, let's stick with the current solution and iterate