README.md

# logical-backup

The operator can manage K8s cron jobs to run logical backups (SQL dumps) of
Postgres clusters. The cron job periodically spawns a batch job that runs a
single pod. The backup script within this pod's container can connect to a DB
for a logical backup. The operator updates cron jobs during Sync if the job
schedule changes; the job name acts as the job identifier. These jobs are to
be enabled for each individual Postgres cluster by updating the manifest:

```yaml
apiVersion: "acid.zalan.do/v1"
kind: postgresql
metadata:
  name: demo-cluster
spec:
  enableLogicalBackup: true
```

There a few things to consider when using logical backups:

1. Logical backups should not be seen as a proper alternative to basebackups
and WAL archiving which are described above. At the moment, the operator cannot
restore logical backups automatically and you do not get point-in-time recovery
but only snapshots of your data. In its current state, see logical backups as a
way to quickly create SQL dumps that you can easily restore in an empty test
cluster.

2. The [example image](https://github.com/zalando/postgres-operator/blob/master/docker/logical-backup/Dockerfile) implements the backup
via `pg_dumpall` and upload of compressed and encrypted results to an S3 bucket.
`pg_dumpall` requires a `superuser` access to a DB and runs on the replica when
possible.

3. Due to the [limitation of K8s cron jobs](https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/#cron-job-limitations)
it is highly advisable to set up additional monitoring for this feature; such
monitoring is outside of the scope of operator responsibilities.

4. The operator does not remove old backups.

5. You may use your own image by overwriting the relevant field in the operator
configuration. Any such image must ensure the logical backup is able to finish
[in presence of pod restarts](https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/#handling-pod-and-container-failures)
and [simultaneous invocations](https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/#cron-job-limitations)
of the backup cron job.

6. For that feature to work, your RBAC policy must enable operations on the
`cronjobs` resource from the `batch` API group for the operator service account.
See [example RBAC](https://github.com/zalando/postgres-operator/blob/master/manifests/operator-service-account-rbac.yaml)