Investigate move to opm for building operator registry

[kaczyns]

We currently use operator-registry tools to build an operator registry (catalog) containing the Kabanero operator, and some other operators that we copy from community-operators. To build the registry, we have a directory of metadata, and we point a Dockerfile at this directory and out pops a container which contains a registry that OLM can query and install operators from.

The operator-registry is transitioning to a new tool called opm which creates Operator Bundles, which in turn are consumed by OLM. See:
https://github.com/operator-framework/operator-registry/blob/master/docs/design/operator-bundle.md

It looks like you build a specific version of an operator into a non-executable container image, using opm. Then you point opm at a set of these and create an index, which creates another container image that can be consumed by OLM in the traditional way (can be put in a catalogsource).

We need to investigate this new format and how we can start using it in Kabanero. OCP version 4.3 is using OLM version 0.13.0, which mentions bundles. OLM 0.14.0 includes more PRs that use bundles, but there is still very little documentation around how to configure OLM to use a bundle. We are also starting to see signs in operator-sdk, that it is no longer going to produce the manifests in the old way, only the newer bundle way (see breaking changes in https://github.com/operator-framework/operator-sdk/releases/tag/v0.17.0). Now granted we don't take advantage of any of the operator-sdk tools that generate the CSV, but this can be taken as a statement of direction regardless.

It may be that OCP 4.4 contains enough of this support that we can transition to using opm at that time. Or we may need to wait for OCP 4.5.

[kaczyns]

Also see:
operator-framework/community-operators#1680

[dacleyra]

OCP 4.3 uses OLM release-4.3 and does not have the bundle support
OCP 4.4 uses OLM release-4.4 and appears to have the bundle support

oc -n openshift-operator-lifecycle-manager describe pod -l app=olm-operator | grep RELEASE_VERSION

https://github.com/operator-framework/operator-lifecycle-manager/blob/release-4.3/doc/design/resolving-bundle-images.md
https://github.com/operator-framework/operator-lifecycle-manager/blob/release-4.4/doc/design/resolving-bundle-images.md

Moving to bundles would appear to require OCP 4.4