Add optional secondary read pool support to the alloydb module (#3529)

* Add optinal secondary read pool support to the alloydb module

* Fix formatting

---------

Co-authored-by: Julio Castillo <jccb@google.com>

tests/modules/alloydb/examples/cross_region_read_pools.yaml

@@ -0,0 +1,166 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+values:
+  module.alloydb.google_alloydb_cluster.primary:
+    annotations: null
+    cluster_id: db
+    cluster_type: PRIMARY
+    continuous_backup_config:
+    - enabled: true
+      encryption_config: []
+      recovery_window_days: 14
+    database_version: POSTGRES_15
+    deletion_policy: DEFAULT
+    deletion_protection: false
+    display_name: db
+    effective_labels:
+      goog-terraform-provisioned: 'true'
+    encryption_config: []
+    etag: null
+    initial_user:
+    - password: changeit
+      user: postgres
+    labels: null
+    location: europe-west8
+    maintenance_update_policy: []
+    network_config:
+    - allocated_ip_range: null
+      network: projects/xxx/global/networks/aaa
+    project: project-id
+    psc_config: []
+    restore_backup_source: []
+    restore_continuous_backup_source: []
+    secondary_config: []
+    skip_await_major_version_upgrade: true
+    subscription_type: STANDARD
+    terraform_labels:
+      goog-terraform-provisioned: 'true'
+    timeouts: null
+  module.alloydb.google_alloydb_cluster.secondary[0]:
+    annotations: null
+    cluster_id: db-sec
+    cluster_type: SECONDARY
+    continuous_backup_config:
+    - enabled: true
+      encryption_config: []
+      recovery_window_days: 14
+    database_version: POSTGRES_15
+    deletion_policy: FORCE
+    deletion_protection: false
+    display_name: db-sec
+    effective_labels:
+      goog-terraform-provisioned: 'true'
+    encryption_config: []
+    etag: null
+    initial_user: []
+    labels: null
+    location: europe-west12
+    maintenance_update_policy: []
+    network_config:
+    - allocated_ip_range: null
+      network: projects/xxx/global/networks/aaa
+    project: project-id
+    psc_config: []
+    restore_backup_source: []
+    restore_continuous_backup_source: []
+    secondary_config:
+    - {}
+    skip_await_major_version_upgrade: true
+    subscription_type: STANDARD
+    terraform_labels:
+      goog-terraform-provisioned: 'true'
+    timeouts: null
+  module.alloydb.google_alloydb_instance.primary:
+    annotations: null
+    availability_type: REGIONAL
+    display_name: db
+    effective_labels:
+      goog-terraform-provisioned: 'true'
+    gce_zone: null
+    instance_id: db
+    instance_type: PRIMARY
+    labels: null
+    machine_config:
+    - cpu_count: 2
+    query_insights_config:
+    - query_plans_per_minute: 5
+      query_string_length: 1024
+      record_application_tags: true
+      record_client_address: true
+    read_pool_config: []
+    terraform_labels:
+      goog-terraform-provisioned: 'true'
+    timeouts: null
+  module.alloydb.google_alloydb_instance.read_pool_primary["primary-read-pool"]:
+    annotations: null
+    display_name: primary-read-pool
+    effective_labels:
+      goog-terraform-provisioned: 'true'
+    gce_zone: null
+    instance_id: primary-read-pool
+    instance_type: READ_POOL
+    labels: null
+    machine_config:
+    - cpu_count: 2
+    read_pool_config:
+    - node_count: 1
+    terraform_labels:
+      goog-terraform-provisioned: 'true'
+    timeouts: null
+  module.alloydb.google_alloydb_instance.read_pool_secondary["secondary-read-pool"]:
+    annotations: null
+    display_name: secondary-read-pool
+    effective_labels:
+      goog-terraform-provisioned: 'true'
+    gce_zone: null
+    instance_id: secondary-read-pool
+    instance_type: READ_POOL
+    labels: null
+    machine_config:
+    - cpu_count: 2
+    read_pool_config:
+    - node_count: 1
+    terraform_labels:
+      goog-terraform-provisioned: 'true'
+    timeouts: null
+  module.alloydb.google_alloydb_instance.secondary[0]:
+    annotations: null
+    availability_type: REGIONAL
+    display_name: db-sec
+    effective_labels:
+      goog-terraform-provisioned: 'true'
+    gce_zone: null
+    instance_id: db-sec
+    instance_type: SECONDARY
+    labels: null
+    machine_config:
+    - cpu_count: 2
+    query_insights_config:
+    - query_plans_per_minute: 5
+      query_string_length: 1024
+      record_application_tags: true
+      record_client_address: true
+    read_pool_config: []
+    terraform_labels:
+      goog-terraform-provisioned: 'true'
+    timeouts: null
+
+counts:
+  google_alloydb_cluster: 2
+  google_alloydb_instance: 4
+  modules: 1
+  resources: 6
+
+outputs: {}

tests/modules/alloydb/examples/read_pool.yaml

@@ -60,7 +60,7 @@ values:
       record_client_address: true
     read_pool_config: []
     timeouts: null
-  module.alloydb.google_alloydb_instance.read_pool["regional-read-pool"]:
+  module.alloydb.google_alloydb_instance.read_pool_primary["regional-read-pool"]:
     annotations: null
     display_name: regional-read-pool
     gce_zone: null
@@ -72,7 +72,7 @@ values:
     read_pool_config:
     - node_count: 2
     timeouts: null
-  module.alloydb.google_alloydb_instance.read_pool["zonal-read-pool"]:
+  module.alloydb.google_alloydb_instance.read_pool_primary["zonal-read-pool"]:
     annotations: null
     display_name: zonal-read-pool
     effective_labels: