Take the key of the number of instances outside CRD?

Please, answer some short questions which should help us to understand your problem / question better?

• Which image of the operator are you using? e.g. registry.opensource.zalan.do/acid/postgres-operator:v1.6.2
• Where do you run it - cloud or metal? Kubernetes or OpenShift? cloud k8s
• Are you running Postgres Operator in production? [yes | no] yes
• Type of issue? [Bug report, question, feature request, etc.] question, feature request

Good day! We use your wonderfull operator in production, but we are faced with the impossibility of autoscaling. I mean autoscaling db and nodes, and it is normal because it is metal issue - nodes.

So we develop node-autoscaler, that changes nodes count in node-group, if it is necessary. But we meet problem, that the count of instancies is in CRD postgresqls.acid.zalan.do. To our mind it is security problem if our autoscaler will be able to change this CRD. It should be able to change only instance count. Our first solution was to create configmap for example, store there number of instancies, and create some simple operator, for example shell-operator that will watch changes, and apply it to CRD. So, in that case, there is no problem if we create service account that will be able to change this configmap, and serious damage will not be possible.

So question - How do you think it would be rational if you take the key of the number of instances outside CRD? It is acrchitecture question, and to our mind it will make operator better. But in what form it shall be done, we dont know. Or here is some mistake?

Review the postgresqls.acid.zalan.do CRD and the node-autoscaler’s instance-count interaction first; no repository files or tests are named. Compare the proposed ConfigMap and shell-operator approach with the current ServiceAccount permissions. Done means a concrete, agreed design for safely changing only the instance count.