init comment-service

services/comment-service/comment_service/postgres/service.py

@@ -0,0 +1,41 @@
+import logging
+
+from databases import Database
+
+from comment_service.models.config import Config
+from comment_service.events.producer import CommentEventProducer
+from comment_service.postgres.repository import ServiceDBRepository
+
+
+async def connect_database(config: Config) -> Database:
+    """Opens a connection to the database.
+    
+    Args:
+        config (Config): The app configuration.
+
+    Returns:
+        A connected databases.Database instance
+
+    """
+    db = Database(config.postgres_dsn)
+    try:
+        await db.connect()
+    except Exception:
+        logging.error("failed to connect to postgresql database")
+        raise
+    
+    return db
+
+
+async def create_db_repository(config: Config, event_producer: CommentEventProducer) -> ServiceDBRepository:
+    """Create the database repository.
+    
+    Open a database connection and instantialise the
+    database repository.
+
+    Returns:
+        ServiceDBRepository
+    
+    """
+    db = await connect_database(config)
+    return ServiceDBRepository(db, event_producer)