Add sync connection methods.

Author: andrew-chang-dewitt

db_wrapper/connection.py

@@ -3,18 +3,18 @@
 import asyncio
 from dataclasses import dataclass
 import logging
-from typing import Optional
+import time
+from typing import Optional, Any
 
+from psycopg2 import (  # type: ignore
+    connect as psycopg2Connect,
+    OperationalError as psycopg2OpError,
+)
 from psycopg2.extras import RealDictCursor  # type: ignore
-from psycopg2 import OperationalError  # type: ignore
 
 # no stubs available, starting out by just determining correct return
 # types & annotating in my wrappers here
-import aiopg  # type: ignore
-
-#
-# Postgres Connection helper
-#
+import aiopg
 
 LOGGER = logging.getLogger(__name__)
 
@@ -54,7 +54,7 @@ async def _try_connect(
             connection = await aiopg.connect(
                 dsn,
                 cursor_factory=RealDictCursor)
-        except OperationalError as err:
+        except psycopg2OpError as err:
             print(type(err))
             if retries > 12:
                 raise ConnectionError(
@@ -71,10 +71,58 @@ async def _try_connect(
     return connection
 
 
+def _sync_try_connect(
+    connection_params: ConnectionParameters,
+    retries: int = 1
+) -> Any:
+    database = connection_params.database
+    user = connection_params.user
+    password = connection_params.password
+    host = connection_params.host
+    port = connection_params.port
+
+    dsn = f'dbname={database} user={user} password={password} host={host} port={port}'
+
+    # PENDS python 3.9 support in pylint
+    # pylint: disable=unsubscriptable-object
+    connection: Optional[aiopg.Connection] = None
+
+    LOGGER.info(
+        f'Attempting to connect to database {database} as {user}@{host}:{port}...')
+
+    while connection is None:
+        try:
+            connection = psycopg2Connect(
+                dsn,
+                cursor_factory=RealDictCursor)
+        except psycopg2OpError as err:
+            print(type(err))
+            if retries > 12:
+                raise ConnectionError(
+                    'Max number of connection attempts has been reached (12)'
+                ) from err
+
+            LOGGER.info(
+                f'Connection failed ({retries} time(s))'
+                'retrying again in 5 seconds...')
+
+            time.sleep(5)
+            return _sync_try_connect(connection_params, retries + 1)
+
+    return connection
+
+
 # PENDS python 3.9 support in pylint
 # pylint: disable=unsubscriptable-object
 async def connect(
     connection_params: ConnectionParameters
 ) -> aiopg.Connection:
     """Establish database connection."""
     return await _try_connect(connection_params)
+
+
+async def sync_connect(
+    connection_params: ConnectionParameters
+) -> Any:
+    """Establish database connection."""
+    return _sync_try_connect(connection_params)