[RDS Controller] controller spams if it could not change the database parameters

[gecube]

The controller constantly spams with the next messages:

{"level":"info","ts":"2024-12-11T03:53:19.894Z","logger":"ackrt","msg":"desired resource state has changed","kind":"DBCluster","namespace":"infra-uat","name":"postdeal-uat","account":"*****","role":"arn:aws:iam::*****:role/ack-ec2-controller","region":"eu-west-2","is_adopted":false,"generation":3,"diff":[{"Path":{"Parts":["Spec","EngineVersion"]},"A":"5.7.mysql_aurora.2.12.0","B":"8.0.mysql_aurora.3.05.2"}]}

{"level":"info","ts":"2024-12-11T03:53:20.388Z","logger":"ackrt","msg":"desired resource state has changed","kind":"DBInstance","namespace":"infra-uat","name":"octagon-uat-2024-10-19","account":"****","role":"arn:aws:iam::*****:role/ack-ec2-controller","region":"eu-west-2","is_adopted":false,"generation":29676,"diff":[{"Path":{"Parts":["Spec","KMSKeyID"]},"A":"arn:aws:kms:eu-west-2:474417630776:key/a85d9411-5cce-4609-b6ba-74535733341a","B":null}]}

{"level":"info","ts":"2024-12-11T03:53:19.742Z","logger":"ackrt","msg":"desired resource state has changed","kind":"DBCluster","namespace":"infra-uat","name":"artemis-uat-4","account":"*****","role":"arn:aws:iam::*****:role/ack-ec2-controller","region":"eu-west-2","is_adopted":false,"generation":152013,"diff":[{"Path":{"Parts":["Spec","AutoMinorVersionUpgrade"]},"A":null,"B":true},{"Path":{"Parts":["Spec","NetworkType"]},"A":null,"B":"IPV4"}]}

I understood the root cause as some of the objects were changed outside of the ACK controller, probably directly from AWS console manually and/or automatically (like DB upgrade).

Right now I don't see any solution for the exception of putting all offensive fields directly into the spec of DBCluster or DBInstance and then controller stop trying to change fields that could not be changed. The KMS Key issue was reported in #2198 - so I can confirm that KMS settings could not be changed on-the-fly.

Probably possible solution would be to allow user ignore some fields in DBCluster spec so controller would not try to reconcile them. It would allow more interesting workflows when you can create DB with some version and then it would be automatically upgraded in the cloud UI (yes, it would not be FULL GITOPS). It is very interesting to hear suggestions from colleagues.