K8SPG-771: Backup snapshots

[mayankshah1607]

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CHANGE DESCRIPTION

Adds support for taking backups using VolumeSnapshots API. VolumeSnapshots enable fast backups directly via the CSI driver.

This PR adds support for offline snapshot backups.

1. Enable snapshots for your cluster

apiVersion: pgv2.percona.com/v2
kind: PerconaPGCluster
metadata:
  name: cluster1
spec:
  backups:
    volumeSnapshots:
      mode: offline
      className: VOLUME-SNAPSHOT-CLASS

2. Trigger a snapshot backup via PerconaPGBackup:

apiVersion: pgv2.percona.com/v2
kind: PerconaPGBackup
metadata:
  name: backup1
spec:
  pgCluster: cluster1
  method: volumeSnapshot

The operator will:

• Select a healthy replica pod and temporarily suspend it.
• Create VolumeSnapshots of its data PVC
• Resume the suspended replica

To take scheduled snapshots:

1. Enable snapshots for your cluster

apiVersion: pgv2.percona.com/v2
kind: PerconaPGCluster
metadata:
  name: cluster1
spec:
  backups:
    volumeSnapshots:
      mode: offline
      className: VOLUME-SNAPSHOT-CLASS
      schedule: "0 0 * * 6"

Later we plan to add support for an online mode where the operator can perform a snapshot on a live primary without suspending it.

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?

[CLAassistant]

All committers have signed the CLA.

[github-actions]

[shfmt] _{reported by reviewdog 🐶}

Suggested change

	rm -f $PGDATA/restored-from-snapshot
	exit 1
	rm -f $PGDATA/restored-from-snapshot
	exit 1

[github-actions]

[shfmt] _{reported by reviewdog 🐶}

Suggested change

	pgbackrest --stanza=db archive-get %f "%p"
	pgbackrest --stanza=db archive-get %f "%p"

[JNKPercona]

Test Name	Result	Time
backup-enable-disable	failure	00:00:00
custom-envs	failure	00:00:00
custom-extensions	failure	00:00:00
custom-tls	failure	00:00:00
database-init-sql	skipped	00:00:00
demand-backup	skipped	00:00:00
finalizers	skipped	00:00:00
init-deploy	skipped	00:00:00
monitoring	skipped	00:00:00
monitoring-pmm3	skipped	00:00:00
one-pod	skipped	00:00:00
operator-self-healing	skipped	00:00:00
pgvector-extension	skipped	00:00:00
pitr	skipped	00:00:00
scaling	skipped	00:00:00
scheduled-backup	skipped	00:00:00
self-healing	skipped	00:00:00
sidecars	skipped	00:00:00
start-from-backup	skipped	00:00:00
tablespaces	skipped	00:00:00
telemetry-transfer	skipped	00:00:00
upgrade-consistency	skipped	00:00:00
upgrade-minor	skipped	00:00:00
users	skipped	00:00:00

Summary	Value
Tests Run	4/24
Job Duration	00:12:55
Total Test Time	N/A

commit: bcd5d04
image: perconalab/percona-postgresql-operator:PR-1418-bcd5d049b