Extract database name to a constant

Author: sinclert-canonical

src/charm.py

@@ -71,6 +71,7 @@
 from constants import (
     APP_SCOPE,
     BACKUP_USER,
+    DATABASE_NAME,
     METRICS_PORT,
     MONITORING_PASSWORD_KEY,
     MONITORING_SNAP_SERVICE,
@@ -373,7 +374,7 @@ def postgresql(self) -> PostgreSQL:
             current_host=self._unit_ip,
             user=USER,
             password=self.get_secret(APP_SCOPE, f"{USER}-password"),
-            database="postgres",
+            database=DATABASE_NAME,
             system_users=SYSTEM_USERS,
         )
 

src/constants.py

@@ -6,6 +6,7 @@
 BACKUP_ID_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
 PGBACKREST_BACKUP_ID_FORMAT = "%Y%m%d-%H%M%S"
 DATABASE = "database"
+DATABASE_NAME = "postgres"
 DATABASE_PORT = "5432"
 LEGACY_DB = "db"
 LEGACY_DB_ADMIN = "db-admin"

tests/integration/helpers.py

@@ -30,6 +30,8 @@
     wait_fixed,
 )
 
+from constants import DATABASE_NAME
+
 CHARM_BASE = "ubuntu@22.04"
 METADATA = yaml.safe_load(Path("./metadata.yaml").read_text())
 DATABASE_APP_NAME = METADATA["name"]
@@ -497,7 +499,7 @@ async def execute_query_on_unit(
     unit_address: str,
     password: str,
     query: str,
-    database: str = "postgres",
+    database: str = DATABASE_NAME,
     sslmode: str | None = None,
 ):
     """Execute given PostgreSQL query on a unit.

tests/integration/new_relations/test_new_relations_1.py

@@ -12,6 +12,8 @@
 from pytest_operator.plugin import OpsTest
 from tenacity import Retrying, stop_after_attempt, wait_fixed
 
+from constants import DATABASE_NAME
+
 from ..helpers import (
     CHARM_BASE,
     assert_sync_standbys,
@@ -277,7 +279,10 @@ async def test_two_applications_doesnt_share_the_same_relation_data(ops_test: Op
         (another_application_app_name, f"{APPLICATION_APP_NAME.replace('-', '_')}_database"),
     ]:
         connection_string = await build_connection_string(
-            ops_test, application, FIRST_DATABASE_RELATION_NAME, database="postgres"
+            ops_test,
+            application,
+            FIRST_DATABASE_RELATION_NAME,
+            database=DATABASE_NAME,
         )
         with pytest.raises(psycopg2.Error):
             psycopg2.connect(connection_string)
@@ -487,7 +492,7 @@ async def test_admin_role(ops_test: OpsTest):
 
     # Check that the user can access all the databases.
     for database in [
-        "postgres",
+        DATABASE_NAME,
         f"{APPLICATION_APP_NAME.replace('-', '_')}_database",
         "another_application_database",
     ]:
@@ -511,11 +516,11 @@ async def test_admin_role(ops_test: OpsTest):
                 )
                 assert version == data
 
-                # Write some data (it should fail in the "postgres" database).
+                # Write some data (it should fail in the default database name).
                 random_name = (
                     f"test_{''.join(secrets.choice(string.ascii_lowercase) for _ in range(10))}"
                 )
-                should_fail = database == "postgres"
+                should_fail = database == DATABASE_NAME
                 cursor.execute(f"CREATE TABLE {random_name}(data TEXT);")
                 if should_fail:
                     assert False, (
@@ -533,7 +538,7 @@ async def test_admin_role(ops_test: OpsTest):
 
     # Test the creation and deletion of databases.
     connection_string = await build_connection_string(
-        ops_test, DATA_INTEGRATOR_APP_NAME, "postgresql", database="postgres"
+        ops_test, DATA_INTEGRATOR_APP_NAME, "postgresql", database=DATABASE_NAME
     )
     connection = psycopg2.connect(connection_string)
     connection.autocommit = True
@@ -542,8 +547,10 @@ async def test_admin_role(ops_test: OpsTest):
     cursor.execute(f"CREATE DATABASE {random_name};")
     cursor.execute(f"DROP DATABASE {random_name};")
     try:
-        cursor.execute("DROP DATABASE postgres;")
-        assert False, "the admin extra user role was able to drop the `postgres` system database"
+        cursor.execute(f"DROP DATABASE {DATABASE_NAME};")
+        assert False, (
+            f"the admin extra user role was able to drop the `{DATABASE_NAME}` system database"
+        )
     except psycopg2.errors.InsufficientPrivilege:
         # Ignore the error, as the admin extra user role mustn't be able to drop
         # the "postgres" system database.

tests/integration/new_relations/test_relations_coherence.py

@@ -9,6 +9,8 @@
 import pytest
 from pytest_operator.plugin import OpsTest
 
+from constants import DATABASE_NAME
+
 from ..helpers import CHARM_BASE, DATABASE_APP_NAME
 from .helpers import build_connection_string
 from .test_new_relations_1 import DATA_INTEGRATOR_APP_NAME
@@ -125,14 +127,14 @@ async def test_relations(ops_test: OpsTest, charm):
 
         for database in [
             DATA_INTEGRATOR_APP_NAME.replace("-", "_"),
-            "postgres",
+            DATABASE_NAME,
         ]:
             logger.info(f"connecting to the following database: {database}")
             connection_string = await build_connection_string(
                 ops_test, DATA_INTEGRATOR_APP_NAME, "postgresql", database=database
             )
             connection = None
-            should_fail = database == "postgres"
+            should_fail = database == DATABASE_NAME
             try:
                 with (
                     psycopg2.connect(connection_string) as connection,
@@ -142,7 +144,7 @@ async def test_relations(ops_test: OpsTest, charm):
                     data = cursor.fetchone()
                     assert data[0] == "some data"
 
-                    # Write some data (it should fail in the "postgres" database).
+                    # Write some data (it should fail in the default database name).
                     random_name = f"test_{''.join(secrets.choice(string.ascii_lowercase) for _ in range(10))}"
                     cursor.execute(f"CREATE TABLE {random_name}(data TEXT);")
                     if should_fail: