management: Add a command to send initial welcome bot messages.

zerver/management/commands/send_welcome_bot_message.py

@@ -0,0 +1,21 @@
+from argparse import ArgumentParser
+from typing import Any
+
+from zerver.lib.management import ZulipBaseCommand
+from zerver.lib.onboarding import send_initial_pms
+
+
+class Command(ZulipBaseCommand):
+    help = """Sends the initial welcome bot message."""
+
+    def add_arguments(self, parser: ArgumentParser) -> None:
+        self.add_user_list_args(
+            parser,
+            help="Email addresses of user(s) to send welcome bot messages to.",
+            all_users_help="Send to every user on the realm.",
+        )
+        self.add_realm_args(parser)
+
+    def handle(self, *args: Any, **options: str) -> None:
+        for user_profile in self.get_users(options, self.get_realm(options), is_bot=False):
+            send_initial_pms(user_profile)