Fix issues caught by linter

* Add a .pylintrc to silence annoying messages
* Fix imports
* Add missing `parse_db_url` function
* Add a new `gn_auth.auth.db.redis` module

4 files changed, 37 insertions, 2 deletions

diff --git a/gn_auth/auth/db/__init__.py b/gn_auth/auth/db/__init__.py
index eab58ef..7bdb38a 100644
--- a/gn_auth/auth/db/__init__.py
+++ b/gn_auth/auth/db/__init__.py
@@ -1 +1,2 @@
+"""Unified database connections module."""
 from .protocols import DbCursor, DbConnection
diff --git a/gn_auth/auth/db/mariadb.py b/gn_auth/auth/db/mariadb.py
index a934fd9..69c1d8e 100644
--- a/gn_auth/auth/db/mariadb.py
+++ b/gn_auth/auth/db/mariadb.py
@@ -1,12 +1,22 @@
 """Connections to MariaDB"""
+import logging
 import traceback
 import contextlib
-from typing import Iterator
+from urllib.parse import urlparse
+from typing import Tuple, Iterator
 
 import MySQLdb as mdb
 
 from .protocols import DbConnection
 
+def parse_db_url(sql_uri: str) -> Tuple:
+    """Parse SQL_URI env variable note:there is a default value for SQL_URI so a
+    tuple result is always expected"""
+    parsed_db = urlparse(sql_uri)
+    return (
+        parsed_db.hostname, parsed_db.username, parsed_db.password,
+        parsed_db.path[1:], parsed_db.port)
+
 @contextlib.contextmanager
 def database_connection(sql_uri) -> Iterator[DbConnection]:
     """Connect to MySQL database."""
@@ -18,7 +28,7 @@ def database_connection(sql_uri) -> Iterator[DbConnection]:
                              port=port or 3306)
     try:
         yield connection
-    except Exception as _exc: # TODO: Make the Exception class less general
+    except mdb.Error as _mdb_err:
         logging.debug(traceback.format_exc())
         connection.rollback()
     finally:
diff --git a/gn_auth/auth/db/redis.py b/gn_auth/auth/db/redis.py
new file mode 100644
index 0000000..fdf1d6f
--- /dev/null
+++ b/gn_auth/auth/db/redis.py
@@ -0,0 +1,22 @@
+"""Connections for Redis."""
+import logging
+import traceback
+import contextlib
+from typing import Iterator
+
+from redis import Redis, RedisError, ConnectionError as RedisConnectionError
+
+@contextlib.contextmanager
+def connection(redis_uri) -> Iterator[Redis]:
+    """Connection to redis"""
+    rconn = Redis.from_url(redis_uri, decode_responses=True)
+    try:
+        if not rconn.ping():
+            raise RedisConnectionError("Could not connect to Redis.")
+        yield rconn
+    except RedisError as _rerr:
+        logging.debug(traceback.format_exc())
+        raise
+    finally:
+        rconn.disconnect()
+        rconn.close()
diff --git a/gn_auth/auth/db/sqlite3.py b/gn_auth/auth/db/sqlite3.py
index 3d94832..be9eb2f 100644
--- a/gn_auth/auth/db/sqlite3.py
+++ b/gn_auth/auth/db/sqlite3.py
@@ -6,6 +6,8 @@ from typing import Any, Callable, Iterator
 
 import traceback
 
+from flask import current_app
+
 from .protocols import DbCursor, DbConnection
 
 @contextlib.contextmanager