{RDBMS} Add warnings that default version for az postgres flexible-server create will be updating to PG17 in future and PG12 will be no longer supported (#30298)

* Add pg 17 support, and pg 12 warning

* Update location capabilites feature support checks

* style fix

Author: nasc17

src/azure-cli/azure/cli/command_modules/rdbms/_flexible_server_location_capabilities_util.py

@@ -46,16 +46,20 @@ def _postgres_parse_list_capability(result):
     if not result:
         raise InvalidArgumentValueError("No available SKUs in this location")
 
-    offer_restricted = [feature for feature in result[0].supported_features if feature.name == "OfferRestricted"]
+    supported_features = result[0].supported_features if result[0].supported_features is not None else []
+    offer_restricted = [feature for feature in supported_features if feature.name == "OfferRestricted"]
+    restricted = offer_restricted[0].status if offer_restricted else None
+    zone_redundant = [feature for feature in supported_features if feature.name == "ZoneRedundantHa"]
+    geo_backup = [feature for feature in supported_features if feature.name == "GeoBackup"]
 
-    if offer_restricted[0].status == "Enabled":
+    if restricted == "Enabled":
         raise InvalidArgumentValueError("The location is restricted for provisioning of flexible servers. Please try using another region.")
 
-    if offer_restricted[0].status != "Disabled":
+    if restricted != "Disabled":
         raise InvalidArgumentValueError("No available SKUs in this location.")
 
-    single_az = result[0].zone_redundant_ha_supported != "Enabled"
-    geo_backup_supported = result[0].geo_backup_supported == "Enabled"
+    single_az = zone_redundant[0].status != "Enabled" if zone_redundant else True
+    geo_backup_supported = geo_backup[0].status == "Enabled" if geo_backup else False
 
     tiers = result[0].supported_server_editions
     tiers_dict = {}

src/azure-cli/azure/cli/command_modules/rdbms/_helptext_pg.py

@@ -35,7 +35,7 @@
         az postgres flexible-server create --location northeurope --resource-group testGroup \\
           --name testserver --admin-user username --admin-password password \\
           --sku-name Standard_D2s_v3 --tier GeneralPurpose --public-access 153.24.26.117 --storage-size 128 \\
-          --tags "key=value" --version 16 --high-availability ZoneRedundant --zone 1 \\
+          --tags "key=value" --version 17 --high-availability ZoneRedundant --zone 1 \\
           --standby-zone 3
   - name: >
       Create a PostgreSQL flexible server using Premium SSD v2 Disks.

src/azure-cli/azure/cli/command_modules/rdbms/validators.py

@@ -303,7 +303,8 @@ def pg_arguments_validator(db_context, location, tier, sku_name, storage_gb, ser
                            auto_grow=None, performance_tier=None,
                            storage_type=None, iops=None, throughput=None):
     validate_server_name(db_context, server_name, 'Microsoft.DBforPostgreSQL/flexibleServers')
-    if not instance:
+    is_create = not instance
+    if is_create:
         list_location_capability_info = get_postgres_location_capability_info(
             db_context.cmd,
             location)
@@ -336,7 +337,7 @@ def pg_arguments_validator(db_context, location, tier, sku_name, storage_gb, ser
     _pg_storage_validator(storage_gb, sku_info, tier, storage_type, iops, throughput, instance)
     _pg_sku_name_validator(sku_name, sku_info, tier, instance)
     _pg_high_availability_validator(high_availability, standby_availability_zone, zone, tier, single_az, instance)
-    _pg_version_validator(version, list_location_capability_info['server_versions'])
+    _pg_version_validator(version, list_location_capability_info['server_versions'], is_create)
     pg_byok_validator(byok_identity, byok_key, backup_byok_identity, backup_byok_key, geo_redundant_backup, instance)
 
 
@@ -438,10 +439,20 @@ def _pg_storage_performance_tier_validator(performance_tier, sku_info, tier=None
                                ' Allowed values : {}'.format(storage_size, performance_tiers))
 
 
-def _pg_version_validator(version, versions):
+def _pg_version_validator(version, versions, is_create):
     if version:
         if version not in versions:
             raise CLIError('Incorrect value for --version. Allowed values : {}'.format(versions))
+        if version == '12':
+            logger.warning("Support for PostgreSQL 12 has officially ended. As a result, "
+                           "the option to select version 12 will be removed in the near future. "
+                           "We recommend selecting PostgreSQL 13 or a later version for "
+                           "all future operations.")
+
+    if is_create:
+        # Warning for upcoming breaking change to default value of pg version
+        logger.warning("The default value for the PostgreSQL server major version "
+                       "will be updating to 17 in the near future.")
 
 
 def _pg_high_availability_validator(high_availability, standby_availability_zone, zone, tier, single_az, instance):