fix: make bank proxy retry on failure

proxies/bank_service/bank.py

@@ -1,14 +1,44 @@
 from django.conf import settings
 import requests
+from requests.adapters import HTTPAdapter
+from urllib3.util.retry import Retry
 from rest_framework import status
 from rest_framework.response import Response
 
 BANK_URL = settings.BANK_URL
 
 
+# Configure retry strategy
+def get_retry_session(retries=5, backoff_factor=0.3,
+                      status_forcelist=(500, 502, 503, 504)):
+    """
+    Create a requests session with retry capabilities.
+
+    Args:
+        retries (int): Number of total retries to allow.
+        backoff_factor (float): A backoff factor to apply between attempts.
+        status_forcelist (tuple): HTTP status codes to retry on.
+
+    Returns:
+        requests.Session: A configured session with retry capabilities
+    """
+    retry_strategy = Retry(
+        total=retries,
+        status_forcelist=status_forcelist,
+        allowed_methods=["GET", "POST"],  # Only retry these methods
+        backoff_factor=backoff_factor
+    )
+    adapter = HTTPAdapter(max_retries=retry_strategy)
+    session = requests.Session()
+    session.mount("http://", adapter)
+    session.mount("https://", adapter)
+    return session
+
+
 def _get(url, params):
     try:
-        response = requests.get(
+        session = get_retry_session()
+        response = session.get(
             url,
             params=params,
             timeout=10
@@ -17,14 +47,15 @@ def _get(url, params):
         return response.json()
     except requests.RequestException as e:
         return Response(
-            {"error": f"Failed to process: {str(e)}"},
+            {"error": f"Failed to process GET request after retries: {str(e)}"},
             status=status.HTTP_500_INTERNAL_SERVER_ERROR
         )
 
 
 def _post(url, payload):
     try:
-        response = requests.post(
+        session = get_retry_session()
+        response = session.post(
             url,
             json=payload,
             timeout=10
@@ -33,7 +64,7 @@ def _post(url, payload):
         return response.json()
     except requests.RequestException as e:
         return Response(
-            {"error": f"Failed to process: {str(e)}"},
+            {"error": f"Failed to process POST request after retries: {str(e)}"},
             status=status.HTTP_500_INTERNAL_SERVER_ERROR
         )
 
@@ -43,9 +74,9 @@ def request_transfer(sender_id: str, receiver_id: str, funds: dict):
     Send a transfer request to the transfer API endpoint.
 
     Args:
-        sender_id (str): UUID of the receiver
+        sender_id (str): UUID of the sender
         receiver_id (str): UUID of the receiver
-        currency_amounts (dict): Dictionary of currency names and amounts
+        funds (dict): Dictionary of currency names and amounts
 
     Returns:
         dict: Response from the transfer API or Response object with error