Initial clean commit

db.py

@@ -0,0 +1,76 @@
+import os
+import psycopg2
+from contextlib import contextmanager
+
+# Database configuration
+DB_HOST = os.environ.get("DB_HOST", "db")
+DB_NAME = os.environ.get("DB_NAME", "rss")
+DB_USER = os.environ.get("DB_USER", "rss")
+DB_PASS = os.environ.get("DB_PASS", "x")
+DB_PORT = os.environ.get("DB_PORT", "5432")
+DB_READ_HOST = os.environ.get("DB_READ_HOST", "db-replica")
+DB_WRITE_HOST = os.environ.get("DB_WRITE_HOST", "db")
+
+@contextmanager
+def get_conn():
+    """Get a database connection (Default: Primary/Write)."""
+    conn = None
+    try:
+        conn = psycopg2.connect(
+            host=DB_HOST,
+            database=DB_NAME,
+            user=DB_USER,
+            password=DB_PASS,
+            port=DB_PORT
+        )
+        yield conn
+    finally:
+        if conn:
+            conn.close()
+
+@contextmanager
+def get_read_conn():
+    """Get a read-only database connection (Replica)."""
+    conn = None
+    try:
+        try:
+            # Attempt to connect to Replica first
+            conn = psycopg2.connect(
+                host=DB_READ_HOST,
+                database=DB_NAME,
+                user=DB_USER,
+                password=DB_PASS,
+                port=DB_PORT,
+                connect_timeout=5
+            )
+        except (psycopg2.OperationalError, psycopg2.InterfaceError) as e:
+            # Fallback to Primary if Replica is down on initial connection
+            print(f"Warning: Replica unreachable ({e}), falling back to Primary for read.")
+            conn = psycopg2.connect(
+                host=DB_WRITE_HOST,
+                database=DB_NAME,
+                user=DB_USER,
+                password=DB_PASS,
+                port=DB_PORT
+            )
+        yield conn
+    finally:
+        if conn:
+            conn.close()
+
+@contextmanager
+def get_write_conn():
+    """Get a write database connection (Primary)."""
+    conn = None
+    try:
+        conn = psycopg2.connect(
+            host=DB_WRITE_HOST,
+            database=DB_NAME,
+            user=DB_USER,
+            password=DB_PASS,
+            port=DB_PORT
+        )
+        yield conn
+    finally:
+        if conn:
+            conn.close()