Spinnaker does not properly clean up old artifacts and resources when redeploying

Issue

An organization may encounter an issue that Spinnaker does not delete old artifacts during a deployment, which are not part of the new deployment. This happens for Kubernetes deployments, which leads to a dirty cluster state and potential security risks e.g old istio rules being existent, and causes significant manual work needed to clean it up.

Cause

This issue is caused by how OSS Spinnaker communicates with Kubernetes, there is currently no automatic way of determining what is and what isn't a used artifact or resource. This issue is being tracked on OSS Spinnaker https://github.com/spinnaker/spinnaker/issues/4236There is also related work going on in this issue https://github.com/spinnaker/spinnaker/issues/4550There are two sides to it. On the one side for singular pipelines that have a set number of resources, this can be handled with a delete resources stage as mentioned in the issue above.For multiple resource pipelines, it gets trickier as there currently isn't an ideal way of tracking those resources