[Request] Env map forwarded to Agent instances should be configurable

[andrewazores]

Describe the feature

In cryostatio/cryostat-operator#670 we have an optional feature implemented that integrates Cryostat with Red Hat Insights for downstream customers. At some level this integration needs to be specific to that particular product, so we have tried to keep that abstraction to the Operator only and only implement generic solutions in the other components as required to support this.

In:

• https://github.com/cryostatio/cryostat/pull/1520
• feat(registration): receive platform env map from server on registration cryostat-agent#143

we have a solution that allows the Cryostat server to pass an additional piece of payload data to Agent instances at registration time. This payload currently contains nothing in most cases, but if the Cryostat server has an environment variable INSIGHTS_PROXY set, then it picks that out, renames it INSIGHTS_SVC and passes that to the Agent registration payload. The Agent can then use this to bootstrap the Red Hat Insights client.

This means that in the Cryostat server, the INSIGHTS_PROXY value is hardcoded - so all three components have at least some level of hardcoded integration behaviour.

Instead of hardcoding in this variable name, the Cryostat server could use another environment variable that provides a list of environment variables that should be passed to registering agents: CRYOSTAT_AGENT_REGISTRATION_VARS=INSIGHTS_PROXY,FOO would instruct the Cryostat server to pass on its environment variables INSIGHTS_PROXY and FOO in the registration payload when Agent instances register.

Then, the Cryostat Operator would deploy Cryostat instances setting both CRYOSTAT_AGENT_REGISTRATION_VARS=INSIGHTS_PROXY and ex. INSIGHTS_PROXY=http://insights-proxy.namespace.svc.cluster.local to fully configure the Cryostat server for this case.

Anything other information?

No response