docs: Remove HostnameAlreadyInUseBouncerError.docs_url.

Now that we introduced an URL for serving permalinks redirecting to
docs in #33444, the docs_url mechanism is no longer needed, as we can
have a URL that's safe to hard-code in register_server.py.

The HostnameAlreadyInUseBouncerError.docs_url has been merged in main
briefly enough, that this should be safe to remove.

zerver/lib/push_notifications.py

@@ -1534,9 +1534,8 @@ class PushNotificationsDisallowedByBouncerError(Exception):
 
 class HostnameAlreadyInUseBouncerError(JsonableError):
     code = ErrorCode.HOSTNAME_ALREADY_IN_USE_BOUNCER_ERROR
-    docs_url = "https://zulip.readthedocs.io/en/latest/production/mobile-push-notifications.html#moving-your-registration-to-a-new-server"
 
-    data_fields = ["hostname", "docs_url"]
+    data_fields = ["hostname"]
 
     def __init__(self, hostname: str) -> None:
         self.hostname: str = hostname

zerver/management/commands/register_server.py

@@ -237,7 +237,6 @@ that registration and saving the updated secret in
                 "code" in content_dict
                 and content_dict["code"] == "HOSTNAME_ALREADY_IN_USE_BOUNCER_ERROR"
             ):
-                docs_url = content_dict["docs_url"]
                 print(
                     "--------------------------------\n"
                     "The hostname is already in use by another server. If you control the hostname \n"
@@ -247,7 +246,7 @@ that registration and saving the updated secret in
                     "\n"
                     "For more information, see: \n"
                     "\n"
-                    f"{docs_url}"
+                    "<https://zulip.com/doc-permalinks/registration-transfer>"
                 )
                 raise CommandError
 

zerver/tests/test_home.py

@@ -1515,5 +1515,12 @@ class TestDocRedirectView(ZulipTestCase):
             "https://zulip.readthedocs.io/en/latest/production/mobile-push-notifications.html#why-a-push-notification-service-is-necessary",
         )
 
+        result = self.client_get("/doc-permalinks/registration-transfer")
+        self.assertEqual(result.status_code, 302)
+        self.assertEqual(
+            result["Location"],
+            "https://zulip.readthedocs.io/en/latest/production/mobile-push-notifications.html#moving-your-registration-to-a-new-server",
+        )
+
         result = self.client_get("/doc-permalinks/invalid-doc-id")
         self.assertEqual(result.status_code, 404)

zerver/tests/test_push_notifications.py

@@ -48,7 +48,6 @@ from zerver.lib.exceptions import JsonableError
 from zerver.lib.push_notifications import (
     APNsContext,
     DeviceToken,
-    HostnameAlreadyInUseBouncerError,
     InvalidRemotePushDeviceTokenError,
     UserPushIdentityCompat,
     b64_to_hex,
@@ -5386,7 +5385,6 @@ class PushBouncerSignupTest(ZulipTestCase):
         result = self.client_post("/api/v1/remotes/server/register", request)
         self.assert_json_error(result, "A server with hostname example.com already exists")
         self.assertEqual(result.json()["code"], "HOSTNAME_ALREADY_IN_USE_BOUNCER_ERROR")
-        self.assertEqual(result.json()["docs_url"], HostnameAlreadyInUseBouncerError.docs_url)
 
     def test_register_contact_email_validation_rules(self) -> None:
         zulip_org_id = str(uuid.uuid4())

zerver/views/home.py

@@ -273,6 +273,7 @@ def doc_permalinks_view(request: HttpRequest, doc_id: str) -> HttpResponse:
         "usage-statistics": "https://zulip.readthedocs.io/en/latest/production/mobile-push-notifications.html#uploading-usage-statistics",
         "basic-metadata": "https://zulip.readthedocs.io/en/latest/production/mobile-push-notifications.html#uploading-basic-metadata",
         "why-service": "https://zulip.readthedocs.io/en/latest/production/mobile-push-notifications.html#why-a-push-notification-service-is-necessary",
+        "registration-transfer": "https://zulip.readthedocs.io/en/latest/production/mobile-push-notifications.html#moving-your-registration-to-a-new-server",
     }
 
     redirect_url = DOC_PERMALINK_MAP.get(doc_id)