Storage docs

docs/BACKUP.md

@@ -240,3 +240,7 @@ make cluster
 make install-minio
 make net # to access the console via a MetalLB LoadBalancer: https://minio-console:9001
 ```
+
+## Reference
+- [API reference](./API_REFERENCE.md)
+- [Example suite](../examples/)

docs/GALERA.md

@@ -360,3 +360,7 @@ Increase this timeout if you consider that your Galera cluster may take longer t
 
 Here it is a list of GitHub issues reported by `mariadb-operator` users which might shed some light in your investigation:
 - https://github.com/mariadb-operator/mariadb-operator/issues?q=is%3Aclosed+label%3Agalera-troubleshoot+
+
+## Reference
+- [API reference](./API_REFERENCE.md)
+- [Example suite](../examples/)

docs/HA.md

@@ -89,3 +89,7 @@ spec:
       operator: "Exists"
       effect: "NoSchedule"
 ``` 
+
+## Reference
+- [API reference](./API_REFERENCE.md)
+- [Example suite](../examples/)

docs/METRICS.md

@@ -96,3 +96,7 @@ To visualize MariaDB metrics, our [Prometheus reference installation](#prometheu
 
 
 ##### [Galera/MariaDB - Overview](https://grafana.com/grafana/dashboards/13106-galera-mariadb-overview/)
+
+## Reference
+- [API reference](./API_REFERENCE.md)
+- [Example suite](../examples/)

docs/STORAGE.md

@@ -0,0 +1,100 @@
+# Storage
+
+> [!WARNING]  
+> This documentation applies to `mariadb-operator` version >= v0.0.26
+
+This operator gives you flexibility to define the storage that will back your `/var/lib/mysql` data directoty mounted by `MariaDB`.
+
+## Configuration
+
+The simplest way to configure storage for your `MariaDB` is:
+
+```yaml
+apiVersion: k8s.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  ...
+  storage:
+    size: 1Gi
+```
+
+This will make use of the default `StorageClass` available in your cluster, but you can also provide a different one:
+
+```yaml
+apiVersion: k8s.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  ...
+  storage:
+    size: 1Gi
+    storageClassName: my-storage-class
+```
+
+Under the scenes, the operator is configuring the `StatefulSet`'s `volumeClaimTemplate` property, which you are also able to provide yourself:
+
+```yaml
+apiVersion: k8s.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  ...
+  storage:
+    size: 1Gi
+    storageClassName: standard
+    volumeClaimTemplate:
+      accessModes:
+      - ReadWriteOnce
+      resources:
+        requests:
+          storage: 1Gi
+      storageClassName: standard
+```
+
+## Volume resize
+
+It is possible to resize your storage after having provisioned a `MariaDB`. We need to distinguish between:
+- PVCs already in use.
+- `StatefulSet` storage size, which will be used when provisioning new replicas.
+
+It is important to note that, for the first case, your `StorageClass` must support volume expansion by declaring the `allowVolumeExpansion = true`. In such case, it will be safe to expand the storage by increasing the `size` and setting `resizeInUseVolumes = true`:
+
+```yaml
+apiVersion: k8s.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  ...
+  storage:
+    size: 2Gi
+    resizeInUseVolumes: true
+    waitForVolumeResize: true
+```
+
+Depending on your storage provider, this operation might take a while, and you can decide to wait for this operation before the `MariaDB` becomes ready by setting `waitForVolumeResize = true`. Operations such as [cluster recovery](./GALERA.md#galera-cluster-recovery) and [primary switchover](./HA.md) will not be performed if the `MariaDB` resource is not ready.
+
+## Ephemeral storage
+
+Provisioning standalone `MariaDB` instances is also possible by setting `ephemeral = true`:
+
+```yaml
+apiVersion: k8s.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  ...
+  storage:
+    ephemeral: true   
+```
+
+This may be useful more multiple use cases, like provisioning ephemeral `MariaDBs` for the integration tests of your CI.
+
+## Reference
+- [API reference](./API_REFERENCE.md)
+- [Example suite](../examples/)

examples/manifests/mariadb_galera_full.yaml

@@ -14,6 +14,13 @@ spec:
     storageClassName: standard
     resizeInUseVolumes: true
     waitForVolumeResize: true
+    volumeClaimTemplate:
+      accessModes:
+      - ReadWriteOnce
+      resources:
+        requests:
+          storage: 1Gi
+      storageClassName: standard
 
   replicas: 3
 

examples/manifests/mariadb_replication_full.yaml

@@ -14,6 +14,13 @@ spec:
     storageClassName: standard
     resizeInUseVolumes: true
     waitForVolumeResize: true
+    volumeClaimTemplate:
+      accessModes:
+      - ReadWriteOnce
+      resources:
+        requests:
+          storage: 1Gi
+      storageClassName: standard
 
   replicas: 3