Run the upgrade as part of the reconciliation for instances that will be switched from unmanaged to managed after the upgrade

[avadhut123pisal]

Run the upgrade as part of the reconciliation for instances that will be switched from unmanaged to managed after the upgrade.

Originally posted by @pavolloffay in #1888 (comment)

[GenPage]

I can take a crack at this. Running into this with collectors set to Upgrade Strategy: none since we use an in-house collector image. We don't set spec.managementState and the operator is throwing:

{"level":"info","ts":"2023-08-17T16:23:13Z","logger":"controllers.OpenTelemetryCollector","msg":"Skipping reconciliation for unmanaged OpenTelemetryCollector resource","opentelemetrycollector":{"name":"otel-gateway","namespace":"opentelemetry-operator-system"},"name":"opentelemetry-operator-system/otel-gateway"}

I thought it was the Upgrade Strategy that was ignoring it at first

[GenPage]

@avadhut123pisal @pavolloffay After looking deeper into the issue, there seems to be some overlap and a need for clarification on the differences between UpgradeStrategy and ManagementState. They both try to achieve similar goals.

I propose a solution where UpgradeStrategy is either completely removed or changed to handle which parts of the spec you want to be managed. (image, config, etc). Thoughts?

[GenPage]

The more I think about it, it should just be a merge strategy, where in this case, we want the upgrade function to add in new values that haven't existed in the past but not override existing ones overridden by cluster-admins (in my case, spec.image)

• UpgradeStrategy: Override, Merge (New Default), None

[iblancasa]

@avadhut123pisal @pavolloffay After looking deeper into the issue, there seems to be some overlap and a need for clarification on the differences between UpgradeStrategy and ManagementState. They both try to achieve similar goals.

The UpgradeStrategy is used to enable or disable the mechanism to upgrade the instance when a new instance of the operator is deployed.
ManagementState is used to enable or disable the reconciliation. It can be used, for instance, for debugging the operator.

They should not be merged.