Add Postgres Archiver Concepts Doc

Signed-off-by: souravbiswassanto <[email protected]>

docs/guides/postgres/concepts/postgres.md

@@ -158,7 +158,7 @@ To learn more about how to setup a HA PostgreSQL cluster in KubeDB, please visit
 
 ### spec.streamingMode
 
-`spec.streamingMode` is an optional field that specifies the streaming mode (_Synchronous / Asynchronous_) of the standby replicas. KubeDB currently supports only **Asynchronous** streaming mode.
+`spec.streamingMode` is an optional field that specifies the streaming mode (_Synchronous / Asynchronous_) of the standby replicas.
 
 ### spec.leaderElection
 

docs/guides/postgres/concepts/postgresArchiver.md

@@ -0,0 +1,173 @@
+---
+title: PostgresArchiver CRD
+menu:
+  docs_{{ .version }}:
+    identifier: pg-PostgresArchiver-archiver-concepts
+    name: PostgresArchiver
+    parent: pg-concepts-PostgresArchiver
+    weight: 10
+menu_name: docs_{{ .version }}
+section_menu_id: guides
+---
+
+> New to KubeDB? Please start [here](/docs/README.md).
+> Also you need to have basic understanding of [Kubestash concepts](https://kubestash.com/docs/v2024.9.30/concepts/) before proceeding.
+# PostgresArchiver
+
+## What is PostgresArchiver
+
+`PostgresArchiver` is a Kubernetes `Custom Resource Definitions` (CRD). It provides declarative configuration for taking `full-backup` and `wal-backup` for `point-in-time-recovery` in a Kubernetes native way. You only need to describe the desired `pitr` configuration in a PostgresArchiver Archiver object, and the KubeDB operator will create Kubernetes objects in the desired state for you.
+
+## PostgresArchiver Spec
+
+As with all other Kubernetes objects, a PostgresArchiver needs `apiVersion`, `kind`, and `metadata` fields. It also needs a `.spec` section.
+
+Below is an example PostgresArchiver object.
+
+```yaml
+apiVersion: archiver.kubedb.com/v1alpha1
+kind: PostgresArchiver
+metadata:
+  name: PostgresArchiver-sample
+  namespace: demo
+spec:
+  pause: false
+  databases:
+    namespaces:
+      from: Selector
+      selector:
+        matchLabels:
+          kubernetes.io/metadata.name: demo
+    selector:
+      matchLabels:
+        archiver: "true"
+  retentionPolicy:
+    name: PostgresArchiver-retention-policy
+    namespace: demo
+  encryptionSecret:
+    name: "encrypt-secret"
+    namespace: "demo"
+  fullBackup:
+    driver: "Restic"
+    scheduler:
+      successfulJobsHistoryLimit: 1
+      failedJobsHistoryLimit: 1
+      schedule: "*/10 * * * *"
+    sessionHistoryLimit: 2
+  manifestBackup:
+    scheduler:
+      successfulJobsHistoryLimit: 1
+      failedJobsHistoryLimit: 1
+      schedule: "30 * * * *"
+    sessionHistoryLimit: 2
+  backupStorage:
+    ref:
+      name: "gcs-storage"
+      namespace: "restore"
+```
+
+### spec.databases
+
+Databases define which Postgres databases are allowed to consume this archiver.
+
+#### spec.databases.namespaces.from
+This indicates namespaces from which Consumers may be attached to. Default value for this field is `same`. Which means only db's from same namespace can consume this postgres archiver.
+Other supported values are `All`, `Selector`. If you use `Selector`, then your consumer namespace labels should be matched with the `.spec.databases.namespaces.selector`.
+
+#### spec.databases.selector (selctor)
+
+This specifies a selector for consumers that are allowed to bind to this database instance. For example, if you have following in your archiver spec,
+```yaml
+selector:
+  matchLabels:
+    archiver: "true"
+```
+then only those consumers will be allowed to consume this who has the below labels.
+```yaml
+metadata:
+  labels:
+    archiver: "true"
+```
+> Note: Only those consumers are allowed to consume this archiver which satisfies both `spec.databases.namespaces` & `spec.databases.selector`.
+
+### spec.pause (bool)
+Pause defines if the backup process should be paused or not. It is a boolean field.
+
+### spec.retentionPolicy (objectReference)
+
+RetentionPolicy field is the RetentionPolicy of the backupConfiguration's backend.
+Check [here](https://kubestash.com/docs/v2024.9.30/concepts/crds/retentionpolicy/) for more details about retentionPolicy.
+
+### spec.fullBackup
+
+FullBackup defines the sessionConfig of the fullBackup. This options will eventually go to the full-backup job's yaml. 
+For knowing more about sessionConfig and Backup, visit [this](https://kubestash.com/docs/v2024.9.30/concepts/crds/backupconfiguration/).
+
+#### spec.fullBackup.driver (string)
+
+Driver specifies the name of underlying tool that is being used to upload the backed up data.
+Supported values are, `Restic`,`WalG`, `VolumeSnapshotter`.
+
+#### spec.fullBackup.task.Params (RawExtension)
+Task will let you provide backup params. To know about `params` section, visit [here](https://kubestash.com/docs/v2024.9.30/concepts/crds/backupconfiguration/#task-reference).
+
+#### spec.fullBackup.scheduler
+
+Checkout [here](https://kubestash.com/docs/v2024.9.30/concepts/crds/backupconfiguration/#scheduler-spec) to know about scheduler. Only `schedule`, `concurrencyPolicy`, `jobTemplate`, `successfulJobsHistoryLimit` and `successfulJobsHistoryLimit` are supported.
+
+#### spec.fullBackup.containerRuntimeSettings
+This provides settings required to run backup pods. Checkout [here](https://github.com/kmodules/offshoot-api/blob/6f79b0d0097965c01877e2e2fa8265b3909eb4de/api/v1/runtime_settings_types.go#L125) for more details.
+#### spec.fullBackup.jobTemplate
+Use to run the backup job. For more info, visit [here](https://github.com/kmodules/offshoot-api/blob/6f79b0d0097965c01877e2e2fa8265b3909eb4de/api/v1/types.go#L42).
+
+#### spec.fullBackup.retryConfig.maxRetry
+MaxRetry specifies the maximum number of times KubeStash should retry the backup/restore process. By default, KubeStash will retry only 1 time.
+#### spec.fullBackup.retryConfig.delay
+The amount of time to wait before next retry. If you don't specify this field, KubeStash will retry immediately. Format: 30s, 2m, 1h etc. 
+
+### spec.walBackup
+
+WalBackup defines the sessionConfig of the walBackup. This options will eventually go to the sidekick specification. We use to run a [sidekick](https://github.com/kubeops/sidekick) pod to take continuous wal backup using wal-g.
+
+#### spec.walBackup.configSecret (genericSecretReference)
+A secret reference which you can use to set custom env's to the wal-backup pod.
+
+#### spec.walBackup.runTimeSettings
+
+Settings to run wal-backup pod. More information can be found [here](https://github.com/kmodules/offshoot-api/blob/6f79b0d0097965c01877e2e2fa8265b3909eb4de/api/v1/runtime_settings_types.go#L26).
+
+### spec.manifestBackup
+
+ManifestBackup defines the sessionConfig of the manifestBackup. This options will eventually go to the manifest-backup job's yaml.  For knowing more about sessionConfig and Backup, visit [this](https://kubestash.com/docs/v2024.9.30/concepts/crds/backupconfiguration/).
+
+Both `ManifestBackup` and `FullBackup` share the following fields:
+- `Scheduler`
+- `ContainerRuntimeSettings`
+- `JobTemplate`
+- `RetryConfig`
+- `Timeout`
+- `SessionHistoryLimit`
+
+### spec.encryptionSecret (objectReference)
+
+EncryptionSecret refers to the Secret containing the encryption key which will be used to encrypt the backed up data. You can refer to a Secret of a different namespace by providing name and namespace fields. This field is optional. No encryption secret is required for VolumeSnapshot backups. 
+To know more about this, visit [here](https://kubestash.com/docs/v2024.9.30/concepts/crds/backupconfiguration/#backupconfiguration-spec). 
+
+### spec.backupStorage
+
+BackupStorage is the backend storageRef of the BackupConfiguration. To learn more about this, visit [here](https://kubestash.com/docs/v2024.9.30/concepts/crds/backupstorage/).
+
+#### spec.backupStorage.ref (objectReference)
+
+Reference to the backupStorage.
+#### spec.backupStorage.subDir (string)
+
+If this is set then this directory path will be used to store the backups.
+
+### spec.deletionPolicy
+DeletionPolicy defines the created repository's deletionPolicy.
+
+## Next Steps
+
+- Learn how to use KubeDB to run a PostgresArchiverQL database [here](/docs/guides/PostgresArchiver/README.md).
+- Want to hack on KubeDB? Check our [contribution guidelines](/docs/CONTRIBUTING.md).