set up cloud sql python connector (#3114)

queue_services/account-mailer/pyproject.toml

@@ -41,6 +41,7 @@ zipp = "3.19.1"
 auth-api = { git = "https://github.com/bcgov/sbc-auth.git", rev = "feature-gcp-migration", subdirectory = "auth-api" }
 simple-cloudevent = { git = "https://github.com/daxiom/simple-cloudevent.py.git" }
 build-deps = { git = "https://github.com/bcgov/sbc-auth.git", rev = "feature-gcp-migration", subdirectory = "build-deps" }
+cloud-sql-python-connector = "^1.13.0"
 
 [tool.poetry.group.dev.dependencies]
 psycopg2 = "^2.9.9"

queue_services/account-mailer/src/account_mailer/__init__.py

@@ -11,13 +11,15 @@
 # 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.
+
 """The Events Listener service.
 
 This module is the service worker for applying filings to the Business Database structure.
 """
 from __future__ import annotations
 
 import os
+from dataclasses import dataclass
 
 from auth_api.exceptions import ExceptionHandler
 from auth_api.models import db
@@ -26,29 +28,78 @@
 from auth_api.services.gcp_queue import queue
 from auth_api.utils.cache import cache
 from flask import Flask
+from google.cloud.sql.connector import Connector
 
-from account_mailer import config
+from account_mailer import config as app_config
 from account_mailer.resources.worker import bp as worker_endpoint
 
 
-def register_endpoints(app: Flask):
-    """Register endpoints with the flask application."""
-    # Allow base route to match with, and without a trailing slash
-    app.url_map.strict_slashes = False
+@dataclass
+class DBConfig:
+    """Database configuration settings."""
+
+    unix_sock: str
+    database: str
+    user: str
+    password: str
+
 
-    app.register_blueprint(
-        url_prefix='/',
-        blueprint=worker_endpoint,
+def getconn(connector: Connector, db_config: DBConfig) -> object:
+    """Create a database connection.
+
+    Args:
+        connector (Connector): The Google Cloud SQL connector instance.
+        db_config (DBConfig): The database configuration.
+
+    Returns:
+        object: A connection object to the database.
+    """
+    return connector.connect(
+        instance_connection_string=db_config.unix_sock.replace('/cloudsql/', ''),
+        ip_type='private',
+        user=db_config.user,
+        password=db_config.password,
+        db=db_config.database,
+        driver='pg8000',
     )
+
+
+def register_endpoints(app: Flask) -> None:
+    """Register endpoints with the Flask application.
+
+    Args:
+        app (Flask): The Flask application instance.
+    """
+    app.url_map.strict_slashes = False
+    app.register_blueprint(worker_endpoint, url_prefix='/')
     app.register_blueprint(ops_bp)
 
 
 def create_app(run_mode=os.getenv('DEPLOYMENT_ENV', 'production')) -> Flask:
-    """Return a configured Flask App using the Factory method."""
+    """Return a configured Flask App using the Factory method.
+
+    Args:
+        run_mode (str): The running mode of the application (e.g., production, development).
+
+    Returns:
+        Flask: The configured Flask application instance.
+    """
     app = Flask(__name__)
-    app.config.from_object(config.get_named_config(run_mode))
+    app.config.from_object(app_config.get_named_config(run_mode))
     app.config['ENV'] = run_mode
 
+    if app.config.get('DB_UNIX_SOCKET'):
+        connector = Connector(refresh_strategy='lazy')
+        db_config = DBConfig(
+            unix_sock=app.config.get('DB_UNIX_SOCKET'),
+            database=app.config.get('DB_NAME'),
+            user=app.config.get('DB_USER'),
+            password=app.config.get('DB_PASSWORD')
+        )
+        app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {
+            'creator': lambda: getconn(connector, db_config)
+        }
+
     db.init_app(app)
     flags.init_app(app)
     cache.init_app(app)

queue_services/account-mailer/src/account_mailer/config.py

@@ -73,7 +73,7 @@ class _Config():  # pylint: disable=too-few-public-methods
     DB_HOST = os.getenv('DATABASE_HOST', '')
     DB_PORT = os.getenv('DATABASE_PORT', '5432')
     if DB_UNIX_SOCKET := os.getenv('DATABASE_UNIX_SOCKET', None):
-        SQLALCHEMY_DATABASE_URI = f'postgresql+psycopg2://{DB_USER}:{DB_PASSWORD}@/{DB_NAME}?host={DB_UNIX_SOCKET}'  # noqa: E231, E501
+        SQLALCHEMY_DATABASE_URI = 'postgresql+pg8000://'
     else:
         SQLALCHEMY_DATABASE_URI = f'postgresql://{DB_USER}:{DB_PASSWORD}@{DB_HOST}:{int(DB_PORT)}/{DB_NAME}'  # noqa: E231, E501