zilencer: Clean up logic around mobile push notifications signup.

This fixes exceptions when sending PMs in development (where we were
trying to connect to the localhost push bouncer, which we weren't
authorized for, but even if we were, it wouldn't work, since there's
no APNS/GCM certs).

At the same time, we also set and order of operations that ensures one
has the opportunity to adjust the server URL before submitting
anything to us.

docs/production/mobile-push-notifications.md

@@ -18,20 +18,20 @@ support forwarding push notifications to a central push notification
 forwarding service.  You can enable this for your Zulip server as
 follows:
 
-1. If you're running Zulip 1.8.1 or newer, you can run `manage.py
-   register_server` from `/home/zulip/deployments/current`.  This
-   command will print the registration data it would send to the
-   mobile push notifications service, ask you to accept the terms of
-   service, and if you accept, register your server.  Otherwise, see
-   the [legacy signup instructions](#legacy-signup).
-
 1. Uncomment the `PUSH_NOTIFICATION_BOUNCER_URL =
    'https://push.zulipchat.com'` line in your `/etc/zulip/settings.py`
    file (i.e. remove the `#` at the start of the line), and
    [restart your Zulip server](../production/maintain-secure-upgrade.html#updating-settings).
    If you installed your Zulip server with a version older than 1.6,
    you'll need to add the line (it won't be there to uncomment).
 
+1. If you're running Zulip 1.8.1 or newer, you can run `manage.py
+   register_server` from `/home/zulip/deployments/current`.  This
+   command will print the registration data it would send to the
+   mobile push notifications service, ask you to accept the terms of
+   service, and if you accept, register your server.  Otherwise, see
+   the [legacy signup instructions](#legacy-signup).
+
 1. If you or your users have already set up the Zulip mobile app,
    you'll each need to log out and log back in again in order to start
    getting push notifications.

zerver/management/commands/register_server.py

@@ -32,7 +32,8 @@ def add_arguments(self, parser: ArgumentParser) -> None:
                             help="Automatically rotate your server's zulip_org_key")
 
     def handle(self, **options: Any) -> None:
-        check_config()
+        if not settings.DEVELOPMENT:
+            check_config()
 
         if not options['agree_to_terms_of_service'] and not options["rotate_key"]:
             raise CommandError(
@@ -43,6 +44,13 @@ def handle(self, **options: Any) -> None:
             raise CommandError("Missing zulip_org_id; run scripts/setup/generate_secrets.py to generate.")
         if not settings.ZULIP_ORG_KEY:
             raise CommandError("Missing zulip_org_key; run scripts/setup/generate_secrets.py to generate.")
+        if settings.PUSH_NOTIFICATION_BOUNCER_URL is None:
+            if settings.DEVELOPMENT:
+                settings.PUSH_NOTIFICATION_BOUNCER_URL = (settings.EXTERNAL_URI_SCHEME +
+                                                          settings.EXTERNAL_HOST)
+            else:
+                raise CommandError("Please uncomment PUSH_NOTIFICATION_BOUNCER_URL "
+                                   "in /etc/zulip/settings.py (remove the '#')")
 
         request = {
             "zulip_org_id": settings.ZULIP_ORG_ID,
@@ -77,7 +85,6 @@ def handle(self, **options: Any) -> None:
         if response.json()['created']:
             print("You've successfully register for the Mobile Push Notification Service!\n"
                   "To finish setup for sending push notifications:")
-            print("- Uncomment PUSH_NOTIFICATION_BOUNCER_URL in /etc/zulip/settings.py (remove the '#')")
             print("- Restart the server, using /home/zulip/deployments/current/scripts/restart-server")
             print("- Return to the documentation to learn how to test push notifications")
         else:

zproject/dev_settings.py

@@ -87,4 +87,3 @@
 
 # Set this True to send all hotspots in development
 ALWAYS_SEND_ALL_HOTSPOTS = False  # type: bool
-PUSH_NOTIFICATION_BOUNCER_URL = EXTERNAL_URI_SCHEME + EXTERNAL_HOST