support for callback configuration and ca injection

[raffaelespazzoli]

Feature Request

CRDs (for version conversion), ValidatingWebhookConfiguration and MutatingWebhookConfiguration (see also #1325) all need to define callbacks.
OLM should help setup the callback and inject the needed ca.

Is your feature request related to a problem? Please describe.
Today OLM does not provide support in setting up callbacks. These are dependent on the cluster in which the operator is being deployed and therefore OLM is the right place in which to put this logic.

Describe the solution you'd like
Assuming the callback is served by the operator pod itself, one way could be to create a service serving a certificate secret.

The service could have a single port and different contexts in case more than one callback is configured. The created secret would be mounted on the pod at a well known location by OLM.
The operator would then be able to use the secret to serve TLS callback connections.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[dinhxuanvu]

@awgreene Can you take a look?