Do not throttle IPs of legitimate users (mozilla#3416)

Change IP throttling to never block legitimate users (identified by having at least 1 approved translation). For blocked IPs we now also log the username if the request is coming from an authenticated user. Log message is also changed a little so it's easier to search for all IPs with excessive requests (blocked and legitimate).

pontoon/base/middleware.py

@@ -99,8 +99,10 @@ def _throttle(self, request):
         return response
 
     def __call__(self, request):
+        response = self.get_response(request)
+
         if settings.THROTTLE_ENABLED is False:
-            return self.get_response(request)
+            return response
 
         ip = get_ip(request)
 
@@ -119,9 +121,21 @@ def __call__(self, request):
         if request_data:
             request_count, first_request_time = request_data
             if request_count >= self.max_count:
+                user = request.user
+
+                # Do not block IPs of legitimate users
+                if user.is_authenticated and user.has_approved_translations:
+                    log.info(f"Not blocking IP {ip} of user {user.username}")
+                    return response
+
                 # Block further requests for block_duration seconds
                 cache.set(blocked_key, True, self.block_duration)
-                log.error(f"Blocked IP {ip} for {self.block_duration} seconds")
+                username = (
+                    user.username if user.is_authenticated else "unauthenticated user"
+                )
+                log.error(
+                    f"Blocking IP {ip} of {username} for {self.block_duration} seconds"
+                )
                 return self._throttle(request)
             else:
                 # Increment the request count and update cache
@@ -134,5 +148,4 @@ def __call__(self, request):
             # Reset the count and timestamp if first request in the period
             cache.set(observed_key, (1, now), self.observation_period)
 
-        response = self.get_response(request)
         return response

pontoon/base/models/user.py

@@ -210,10 +210,14 @@ def user_status(self, locale):
 
 @property
 def contributed_translations(self):
-    """Filtered contributions provided by user."""
-    from pontoon.base.models.translation import Translation
+    """Contributions provided by user."""
+    return self.translation_set.all()
 
-    return Translation.objects.filter(user=self)
+
+@property
+def has_approved_translations(self):
+    """Return True if the user has approved translations."""
+    return self.translation_set.filter(approved=True).exists()
 
 
 @property
@@ -441,6 +445,7 @@ def latest_action(self):
 User.add_to_class("locale_role", user_locale_role)
 User.add_to_class("status", user_status)
 User.add_to_class("contributed_translations", contributed_translations)
+User.add_to_class("has_approved_translations", has_approved_translations)
 User.add_to_class("top_contributed_locale", top_contributed_locale)
 User.add_to_class("can_translate", can_translate)
 User.add_to_class("is_new_contributor", is_new_contributor)