K8SPG-1062: treat pgbouncer with 0 replicas as disabled

[pooknull]

https://perconadev.atlassian.net/browse/K8SPG-1062

DESCRIPTION

Problem:
When pgbouncer is scaled down to 0, it's service remains and pg endpoint is still points to the pgbouncer service.

Solution:
Operator should treat pgbouncer with 0 size as disabled throughout the operator.

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?

Config/Logging/Testability

• Are all needed new/changed options added to default YAML files?
• Are all needed new/changed options added to the Helm Chart?
• Did we add proper logging messages for operator actions?
• Did we ensure compatibility with the previous version or cluster upgrade process?
• Does the change support oldest and newest supported PG version?
• Does the change support oldest and newest supported Kubernetes version?

[Copilot]

Pull request overview

This PR addresses K8SPG-1062 by making the operator treat PgBouncer configured with replicas: 0 as disabled, preventing the Pg endpoint/host selection and reconciliation from continuing to target or maintain PgBouncer resources when it is intentionally scaled to zero.

Changes:

• Added PGBouncerEnabled() helpers to both upstream (v1beta1) and Percona (v2) proxy specs to centralize the “replicas == 0 means disabled” logic.
• Updated host selection and PgBouncer reconciliation paths to use PGBouncerEnabled() instead of only checking for nil proxy/PgBouncer configs.
• Added unit test coverage for the “zero replicas” behavior in host selection and PgBouncer Service generation.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pkg/apis/upstream.pgv2.percona.com/v1beta1/postgrescluster_types.go	Adds PostgresProxySpec.PGBouncerEnabled() to treat replicas: 0 as disabled for upstream clusters.
pkg/apis/pgv2.percona.com/v2/perconapgcluster_types.go	Adds PGProxySpec.PGBouncerEnabled() for Percona CRD usage.
percona/controller/pgcluster/status.go	Uses PGBouncerEnabled() to select primary service host when PgBouncer is effectively disabled.
percona/controller/pgcluster/gethost_test.go	Adds a test case ensuring replicas: 0 results in primary-service host selection.
internal/pgbouncer/reconcile.go	Skips PgBouncer asset reconciliation when PGBouncerEnabled() is false.
internal/controller/postgrescluster/postgres.go	Avoids adding PgBouncer connection info to user secrets when replicas: 0.
internal/controller/postgrescluster/pgbouncer.go	Treats replicas: 0 like disabled across PgBouncer resource reconciliation (create/update vs delete).
internal/controller/postgrescluster/pgbouncer_test.go	Adds a test ensuring PgBouncer Service is not “specified” when replicas: 0.

[JNKPercona]

Test Name	Result	Time
backup-enable-disable	passed	00:00:00
builtin-extensions	passed	00:00:00
cert-manager-tls	passed	00:00:00
custom-envs	passed	00:00:00
custom-tls	passed	00:00:00
database-init-sql	passed	00:00:00
demand-backup	passed	00:00:00
demand-backup-offline-snapshot	passed	00:13:35
dynamic-configuration	passed	00:00:00
finalizers	passed	00:00:00
init-deploy	passed	00:00:00
huge-pages	passed	00:00:00
major-upgrade-14-to-15	passed	00:00:00
major-upgrade-15-to-16	passed	00:00:00
major-upgrade-16-to-17	passed	00:00:00
major-upgrade-17-to-18	passed	00:00:00
ldap	passed	00:00:00
ldap-tls	passed	00:00:00
monitoring	passed	00:00:00
monitoring-pmm3	passed	00:00:00
one-pod	passed	00:00:00
operator-self-healing	passed	00:00:00
pitr	passed	00:00:00
scaling	passed	00:00:00
scheduled-backup	passed	00:00:00
self-healing	passed	00:00:00
sidecars	passed	00:00:00
standby-pgbackrest	passed	00:00:00
standby-streaming	passed	00:00:00
start-from-backup	passed	00:00:00
tablespaces	passed	00:00:00
telemetry-transfer	passed	00:00:00
upgrade-consistency	passed	00:00:00
upgrade-minor	passed	00:00:00
users	passed	00:00:00
migration-from-crunchy-standby	passed	00:00:00
migration-from-crunchy-pv	passed	00:00:00
migration-from-crunchy-backup-restore	passed	00:00:00

Summary	Value
Tests Run	38/38
Job Duration	00:27:42
Total Test Time	00:13:35

commit: 5ae8a8d
image: perconalab/percona-postgresql-operator:PR-1670-5ae8a8d55