K8SPSMDB-1002: add crd preferer primary node

[sergelogvinov]

Add crd parameter to prefer primary node in cluster.

CHANGE DESCRIPTION

Problem:

K8SPSMDB-1002: The ability to change the primary node through the operator

Cause:

During the planned zone switchover process, the only way to change the primary node is to scale down the operator, adjust the node priority, and then scale the operator back up.

Solution:

CRD changes:

spec:
  replsets:
    primaryPreferTagSelector:
      region: region-1
      zone: region-1a

CHECKLIST

Jira

• Is the Jira ticket created and referenced properly?
• Does the Jira ticket have the proper statuses for documentation (Needs Doc) and QA (Needs QA)?
• Does the Jira ticket link to the proper milestone (Fix Version field)?

Tests

• Is an E2E test/test case added for the new feature/change?
• Are unit tests added where appropriate?
• Are OpenShift compare files changed for E2E tests (compare/*-oc.yml)?

Config/Logging/Testability

• Are all needed new/changed options added to default YAML files?
• Did we add proper logging messages for operator actions? (Configuring member votes and priorities - already exists)
• Did we ensure compatibility with the previous version or cluster upgrade process?
• Does the change support oldest and newest supported MongoDB version?
• Does the change support oldest and newest supported Kubernetes version?

[egegunes]

Hi @sergelogvinov, thank you for your contribution. This looks good but I want to test these changes before approving. @hors if everything is OK, are you OK with including this to v1.18.0?

I only have doubts about the new field name primaryPreferTagSelector, which @spron-in can provide his input, and changes in SetVotes.

[sergelogvinov]

The name primaryPreferTagSelector reminds me of the Kubernetes naming style - Prefer, similar to the affinity preference selector, and TagSelector, resembling the NodeSelector. The term primary is also a common role associated with databases.

Regarding SetVotes, after discussing it with my colleagues, it seems that only those with experience in MongoDB are familiar with its meaning.

Would you mind asking your colleagues for their thoughts on this? I can change it at any time.

[inelpandzic]

@sergelogvinov @egegunes @hors I tested this PR and everything is ok. The field name is also good.
We can merge this one.
Thanks @sergelogvinov for the contribution!

[hors]

@sergelogvinov, please add a new field to https://github.com/percona/percona-server-mongodb-operator/blob/main/deploy/cr.yaml and comment it by default. We use this file as an example, so all fields should be present.

[sergelogvinov]

@sergelogvinov, please add a new field to https://github.com/percona/percona-server-mongodb-operator/blob/main/deploy/cr.yaml and comment it by default. We use this file as an example, so all fields should be present.

done

[JNKPercona]

Test name	Status
arbiter	passed
balancer	passed
custom-replset-name	passed
custom-tls	passed
cross-site-sharded	passed
data-at-rest-encryption	passed
data-sharded	passed
demand-backup	passed
demand-backup-eks-credentials	passed
demand-backup-physical	passed
demand-backup-physical-sharded	passed
demand-backup-sharded	passed
expose-sharded	passed
ignore-labels-annotations	passed
init-deploy	passed
finalizer	passed
ldap	passed
ldap-tls	passed
limits	passed
liveness	passed
mongod-major-upgrade	passed
mongod-major-upgrade-sharded	passed
monitoring-2-0	failure
multi-cluster-service	passed
non-voting	passed
one-pod	passed
operator-self-healing-chaos	passed
pitr	passed
pitr-sharded	passed
pitr-physical	passed
pvc-resize	passed
recover-no-primary	passed
rs-shard-migration	passed
scaling	passed
scheduled-backup	passed
security-context	passed
self-healing-chaos	passed
service-per-pod	passed
serviceless-external-nodes	passed
smart-update	passed
split-horizon	passed
storage	passed
tls-issue-cert-manager	passed
upgrade	passed
upgrade-consistency	passed
upgrade-consistency-sharded-tls	passed
upgrade-sharded	passed
users	passed
version-service	passed
We run 49 out of 49

commit: 9c3717a
image: perconalab/percona-server-mongodb-operator:PR-1629-9c3717a0

[hors]

@sergelogvinov thank you for your contribution. We will include this improvement in the next PSMDBO release (1.18.0).