Backport Add cross-region replication support to AlloyDB

Backport hashicorp/terraform-provider-google-beta#6474

To Create a Secondary Cluster, `cluster_type` and `secondary_config` are the additional fields to be mentioned in the cluster. The secondary cluster is dependent on the primary instance and the same needs to be added in the config using the `depends_on` field. The field continuous_backup_config.enabled needs to be set false as continuous backup is not supported for secondary clusters. The deletion_policy is set to FORCE as the secondary instance that will be created in the secondary cluster can not be deleted independently, but instead the entire secondary cluster needs to be deleted forcefully along with its secondary instance.

```
  cluster_type = "SECONDARY"
  deletion_policy = "FORCE"
  secondary_config {
    primary_cluster_name = <fully qualified primary cluster name>
    // Eg: primary_cluster_name = google_alloydb_cluster.<primary_cluster_name>.name
  }

  continuous_backup_config {
    enabled = false
  }

  depends_on = [google_alloydb_instance.<primary_instance_name>]
```

Part of [hashicorp/terraform-provider-google#13251](hashicorp/terraform-provider-google#13251)

**Release Note Template for Downstream PRs (will be copied)**

```
alloydb: added `cluster_type` and `secondary_config` fields to support secondary clusters in `google_alloydb_cluster` resource.
```

Derived from [GoogleCloudPlatform/magic-modules#9012](GoogleCloudPlatform/magic-modules#9012)

config/crds/resources/apiextensions.k8s.io_v1_customresourcedefinition_alloydbclusters.alloydb.cnrm.cloud.google.com.yaml

@@ -178,6 +178,11 @@ spec:
                     - startTimes
                     type: object
                 type: object
+              clusterType:
+                description: 'Immutable. The type of cluster. If not set, defaults
+                  to PRIMARY. Default value: "PRIMARY" Possible values: ["PRIMARY",
+                  "SECONDARY"].'
+                type: string
               continuousBackupConfig:
                 description: |-
                   The continuous backup config for this cluster.
@@ -505,6 +510,19 @@ spec:
                 - clusterRef
                 - pointInTime
                 type: object
+              secondaryConfig:
+                description: Configuration of the secondary cluster for Cross Region
+                  Replication. This should be set if and only if the cluster is of
+                  type SECONDARY.
+                properties:
+                  primaryClusterName:
+                    description: |-
+                      Immutable. Name of the primary cluster must be in the format
+                      'projects/{project}/locations/{location}/clusters/{cluster_id}'.
+                    type: string
+                required:
+                - primaryClusterName
+                type: object
             required:
             - location
             - projectRef
@@ -796,6 +814,11 @@ spec:
                     - startTimes
                     type: object
                 type: object
+              clusterType:
+                description: 'Immutable. The type of cluster. If not set, defaults
+                  to PRIMARY. Default value: "PRIMARY" Possible values: ["PRIMARY",
+                  "SECONDARY"].'
+                type: string
               continuousBackupConfig:
                 description: |-
                   The continuous backup config for this cluster.
@@ -1123,6 +1146,19 @@ spec:
                 - clusterRef
                 - pointInTime
                 type: object
+              secondaryConfig:
+                description: Configuration of the secondary cluster for Cross Region
+                  Replication. This should be set if and only if the cluster is of
+                  type SECONDARY.
+                properties:
+                  primaryClusterName:
+                    description: |-
+                      Immutable. Name of the primary cluster must be in the format
+                      'projects/{project}/locations/{location}/clusters/{cluster_id}'.
+                    type: string
+                required:
+                - primaryClusterName
+                type: object
             required:
             - location
             - projectRef

scripts/generate-google3-docs/resource-reference/generated/resource-docs/alloydb/alloydbcluster.md

@@ -100,6 +100,7 @@ automatedBackupPolicy:
       minutes: integer
       nanos: integer
       seconds: integer
+clusterType: string
 continuousBackupConfig:
   enabled: boolean
   encryptionConfig:
@@ -149,6 +150,8 @@ restoreContinuousBackupSource:
     name: string
     namespace: string
   pointInTime: string
+secondaryConfig:
+  primaryClusterName: string
 ```
 
 <table class="properties responsive">
@@ -393,6 +396,16 @@ A duration in seconds with up to nine fractional digits, terminated by 's'. Exam
             <p>{% verbatim %}Seconds of minutes of the time. Currently, only the value 0 is supported.{% endverbatim %}</p>
         </td>
     </tr>
+    <tr>
+        <td>
+            <p><code>clusterType</code></p>
+            <p><i>Optional</i></p>
+        </td>
+        <td>
+            <p><code class="apitype">string</code></p>
+            <p>{% verbatim %}Immutable. The type of cluster. If not set, defaults to PRIMARY. Default value: "PRIMARY" Possible values: ["PRIMARY", "SECONDARY"].{% endverbatim %}</p>
+        </td>
+    </tr>
     <tr>
         <td>
             <p><code>continuousBackupConfig</code></p>
@@ -892,6 +905,27 @@ projects/{project}/global/networks/{network_id}.{% endverbatim %}</p>
             <p>{% verbatim %}Immutable. The point in time that this cluster is restored to, in RFC 3339 format.{% endverbatim %}</p>
         </td>
     </tr>
+    <tr>
+        <td>
+            <p><code>secondaryConfig</code></p>
+            <p><i>Optional</i></p>
+        </td>
+        <td>
+            <p><code class="apitype">object</code></p>
+            <p>{% verbatim %}Configuration of the secondary cluster for Cross Region Replication. This should be set if and only if the cluster is of type SECONDARY.{% endverbatim %}</p>
+        </td>
+    </tr>
+    <tr>
+        <td>
+            <p><code>secondaryConfig.primaryClusterName</code></p>
+            <p><i>Required*</i></p>
+        </td>
+        <td>
+            <p><code class="apitype">string</code></p>
+            <p>{% verbatim %}Immutable. Name of the primary cluster must be in the format
+'projects/{project}/locations/{location}/clusters/{cluster_id}'.{% endverbatim %}</p>
+        </td>
+    </tr>
 </tbody>
 </table>
 

third_party/github.com/hashicorp/terraform-provider-google-beta/google-beta/services/alloydb/resource_alloydb_cluster.go

@@ -2012,3 +2012,29 @@ func expandAlloydbClusterAutomatedBackupPolicyEnabled(v interface{}, d tpgresour
 	return v, nil
 }
 
+func expandAlloydbClusterClusterType(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
+	return v, nil
+}
+
+func expandAlloydbClusterSecondaryConfig(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
+	l := v.([]interface{})
+	if len(l) == 0 || l[0] == nil {
+		return nil, nil
+	}
+	raw := l[0]
+	original := raw.(map[string]interface{})
+	transformed := make(map[string]interface{})
+
+	transformedPrimaryClusterName, err := expandAlloydbClusterSecondaryConfigPrimaryClusterName(original["primary_cluster_name"], d, config)
+	if err != nil {
+		return nil, err
+	} else if val := reflect.ValueOf(transformedPrimaryClusterName); val.IsValid() && !tpgresource.IsEmptyValue(val) {
+		transformed["primaryClusterName"] = transformedPrimaryClusterName
+	}
+
+	return transformed, nil
+}
+
+func expandAlloydbClusterSecondaryConfigPrimaryClusterName(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
+	return v, nil
+}