parse forwarded headers for ip

util/request.py

@@ -21,6 +21,10 @@ def get_request_ip():
     if os.getenv("TEST", "false").lower() == "true":
         remote_addr = request.headers.get("X-Override-Remote-Addr-For-Testing", remote_addr)
 
+    if request.headers.get("X-Forwarded-For"):
+        # first ip address in the list of forwarded ips is the client's
+        return request.headers.get("X-Forwarded-For").split(",")[0].strip()
+
     return remote_addr
 
 

util/test/test_request.py

@@ -0,0 +1,52 @@
+import os
+import unittest
+from unittest.mock import MagicMock, patch
+
+from flask import Flask
+from werkzeug.test import EnvironBuilder
+from werkzeug.wrappers import Request
+
+from util.request import get_request_ip
+
+
+class TestGetRequestIP(unittest.TestCase):
+    def setUp(self):
+        self.app = Flask(__name__)
+        self.app_context = self.app.app_context()
+        self.app_context.push()
+
+    def tearDown(self):
+        self.app_context.pop()
+
+    def _create_request(self, remote_addr=None, headers=None):
+        """Helper method to create a test request"""
+        builder = EnvironBuilder(headers=headers or {})
+        env = builder.get_environ()
+        if remote_addr:
+            env["REMOTE_ADDR"] = remote_addr
+        return Request(env)
+
+    def test_x_forwarded_for_single_ip(self):
+        """Test getting IP from X-Forwarded-For with single IP"""
+        headers = {"X-Forwarded-For": "203.0.113.195"}
+        with patch("util.request.request", self._create_request(headers=headers)):
+            self.assertEqual(get_request_ip(), "203.0.113.195")
+
+    def test_x_forwarded_for_multiple_ips(self):
+        """Test getting IP from X-Forwarded-For with multiple IPs"""
+        headers = {"X-Forwarded-For": "203.0.113.195, 70.41.3.18, 150.172.238.178"}
+        with patch("util.request.request", self._create_request(headers=headers)):
+            # Should return first IP (client's IP)
+            self.assertEqual(get_request_ip(), "203.0.113.195")
+
+    def test_empty_x_forwarded_for(self):
+        """Test with empty X-Forwarded-For header"""
+        headers = {"X-Forwarded-For": ""}
+        with patch(
+            "util.request.request", self._create_request(remote_addr="192.168.1.1", headers=headers)
+        ):
+            self.assertEqual(get_request_ip(), "192.168.1.1")
+
+
+if __name__ == "__main__":
+    unittest.main()