DPE-2617 Basic profile support

config.yaml

@@ -26,3 +26,11 @@ options:
     default: false
     type: boolean
     description: Enable unaccent extension
+  profile:
+   description: |
+      Profile representing the scope of deployment, and used to tune resource allocation.
+      Allowed values are: “production” and “testing”.
+      Production will tune postgresql for maximum performance while testing will tune for
+      minimal running performance.
+   type: string
+   default: production

lib/charms/postgresql_k8s/v0/postgresql.py

@@ -19,7 +19,7 @@
 Any charm using this library should import the `psycopg2` or `psycopg2-binary` dependency.
 """
 import logging
-from typing import List, Set, Tuple
+from typing import List, Optional, Set, Tuple
 
 import psycopg2
 from psycopg2 import sql
@@ -32,7 +32,7 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 12
+LIBPATCH = 13
 
 INVALID_EXTRA_USER_ROLE_BLOCKING_MESSAGE = "invalid role(s) for extra user roles"
 
@@ -419,3 +419,20 @@ def update_user_password(self, username: str, password: str) -> None:
         finally:
             if connection is not None:
                 connection.close()
+
+    @staticmethod
+    def build_postgresql_parameters(
+        profile: str, available_memory: int
+    ) -> Optional[dict[str, str]]:
+        """Builds the PostgreSQL parameters.
+
+        Args:
+            profile: the profile to use.
+            available_memory: available memory to use in calculation
+
+        Returns:
+            Dictionary with the PostgreSQL parameters.
+        """
+        logger.debug(f"Building PostgreSQL parameters for {profile=} and {available_memory=}")
+        if profile == "production":
+            return {"shared_buffers": "987MB", "effective_cache_size": "2958MB"}

src/charm.py

@@ -1368,6 +1368,7 @@ def update_config(self, is_creating_backup: bool = False) -> bool:
             backup_id=self.app_peer_data.get("restoring-backup"),
             stanza=self.app_peer_data.get("stanza"),
             restore_stanza=self.app_peer_data.get("restore-stanza"),
+            parameters=self.postgresql.build_postgresql_parameters(self.config["profile"], 0),
         )
         if not self._is_workload_running:
             # If Patroni/PostgreSQL has not started yet and TLS relations was initialised,

src/cluster.py

@@ -62,8 +62,6 @@ class UpdateSyncNodeCountError(Exception):
 class Patroni:
     """This class handles the bootstrap of a PostgreSQL database through Patroni."""
 
-    pass
-
     def __init__(
         self,
         unit_ip: str,
@@ -447,6 +445,7 @@ def render_patroni_yml_file(
         stanza: str = None,
         restore_stanza: Optional[str] = None,
         backup_id: Optional[str] = None,
+        parameters: Optional[dict[str, str]] = None,
     ) -> None:
         """Render the Patroni configuration file.
 
@@ -457,6 +456,7 @@ def render_patroni_yml_file(
             stanza: name of the stanza created by pgBackRest.
             restore_stanza: name of the stanza used when restoring a backup.
             backup_id: id of the backup that is being restored.
+            parameters: PostgreSQL parameters to be added to the postgresql.conf file.
         """
         # Open the template patroni.yml file.
         with open("templates/patroni.yml.j2", "r") as file:
@@ -486,6 +486,7 @@ def render_patroni_yml_file(
             restore_stanza=restore_stanza,
             version=self.get_postgresql_version().split(".")[0],
             minority_count=self.planned_units // 2,
+            pg_parameters=parameters,
         )
         self.render_file(f"{PATRONI_CONF_PATH}/patroni.yaml", rendered, 0o600)
 

templates/patroni.yml.j2

@@ -64,6 +64,11 @@ bootstrap:
         {%- endif %}
         archive_mode: on
         wal_level: logical
+        {%- if pg_parameters %}
+        {%- for key, value in pg_parameters.items() %}
+        {{key}}: {{value}}
+        {%- endfor -%}
+        {% endif %}
 
   {%- if restoring_backup %}
   method: pgbackrest

tests/integration/ha_tests/test_replication.py

@@ -29,7 +29,12 @@ async def test_build_and_deploy(ops_test: OpsTest) -> None:
         wait_for_apps = True
         charm = await ops_test.build_charm(".")
         async with ops_test.fast_forward():
-            await ops_test.model.deploy(charm, num_units=3, series=CHARM_SERIES)
+            await ops_test.model.deploy(
+                charm,
+                num_units=3,
+                series=CHARM_SERIES,
+                config={"profile": "testing"},
+            )
     # Deploy the continuous writes application charm if it wasn't already deployed.
     if not await app_name(ops_test, APPLICATION_NAME):
         wait_for_apps = True
@@ -111,7 +116,11 @@ async def test_no_data_replicated_between_clusters(ops_test: OpsTest, continuous
         charm = await ops_test.build_charm(".")
         async with ops_test.fast_forward():
             await ops_test.model.deploy(
-                charm, application_name=new_cluster_app, num_units=2, series=CHARM_SERIES
+                charm,
+                application_name=new_cluster_app,
+                num_units=2,
+                series=CHARM_SERIES,
+                config={"profile": "testing"},
             )
             await ops_test.model.wait_for_idle(apps=[new_cluster_app], status="active")
 

tests/integration/ha_tests/test_restore_cluster.py

@@ -42,11 +42,16 @@ async def test_build_and_deploy(ops_test: OpsTest) -> None:
             num_units=3,
             series=CHARM_SERIES,
             storage={"pgdata": {"pool": "lxd-btrfs", "size": 2048}},
+            config={"profile": "testing"},
         )
 
         # Deploy the second cluster
         await ops_test.model.deploy(
-            charm, application_name=SECOND_APPLICATION, num_units=1, series=CHARM_SERIES
+            charm,
+            application_name=SECOND_APPLICATION,
+            num_units=1,
+            series=CHARM_SERIES,
+            config={"profile": "testing"},
         )
 
         await ops_test.model.wait_for_idle(status="active", timeout=1000)

tests/integration/ha_tests/test_self_healing.py

@@ -75,6 +75,7 @@ async def test_build_and_deploy(ops_test: OpsTest) -> None:
                 num_units=3,
                 series=CHARM_SERIES,
                 storage={"pgdata": {"pool": "lxd-btrfs", "size": 2048}},
+                config={"profile": "testing"},
             )
     # Deploy the continuous writes application charm if it wasn't already deployed.
     if not await app_name(ops_test, APPLICATION_NAME):

tests/integration/test_db.py

@@ -40,6 +40,7 @@ async def test_mailman3_core_db(ops_test: OpsTest, charm: str) -> None:
             application_name=DATABASE_APP_NAME,
             num_units=DATABASE_UNITS,
             series=CHARM_SERIES,
+            config={"profile": "testing"},
         )
 
         # Wait until the PostgreSQL charm is successfully deployed.

tests/integration/test_password_rotation.py

@@ -29,6 +29,7 @@ async def test_deploy_active(ops_test: OpsTest):
             application_name=APP_NAME,
             num_units=3,
             series=CHARM_SERIES,
+            config={"profile": "testing"},
         )
         await ops_test.model.wait_for_idle(apps=[APP_NAME], status="active", timeout=1000)
 

tests/integration/test_tls.py

@@ -42,6 +42,7 @@ async def test_deploy_active(ops_test: OpsTest):
             application_name=APP_NAME,
             num_units=3,
             series=CHARM_SERIES,
+            config={"profile": "testing"},
         )
         # No wait between deploying charms, since we can't guarantee users will wait. Furthermore,
         # bundles don't wait between deploying charms.

tests/unit/test_charm.py

@@ -1053,6 +1053,7 @@ def test_update_config(
             postgresql_mock.is_tls_enabled = PropertyMock(side_effect=[False, False, False, False])
             _is_workload_running.side_effect = [True, True, False, True]
             _member_started.side_effect = [True, True, False]
+            postgresql_mock.build_postgresql_parameters.return_value = {"test": "test"}
 
             # Test without TLS files available.
             self.harness.update_relation_data(
@@ -1067,6 +1068,7 @@ def test_update_config(
                 backup_id=None,
                 stanza=None,
                 restore_stanza=None,
+                parameters={"test": "test"},
             )
             _reload_patroni_configuration.assert_called_once()
             _restart.assert_not_called()
@@ -1089,6 +1091,7 @@ def test_update_config(
                 backup_id=None,
                 stanza=None,
                 restore_stanza=None,
+                parameters={"test": "test"},
             )
             _reload_patroni_configuration.assert_called_once()
             _restart.assert_called_once()