nagios-plugins: Add websocket checking to nagios message sending test.

- Add websocket client to create connection with SockJS websocket server.
  It contains callback method to launch after connection setup.
- Add '--websocket' parameter to 'check_send_receive_time' script to
  check websocket connection.
- Add testing  websocket connection to production installation checking.
- Add cronjob to launch websocket connection nagios test.

This makes it possible for Zulip Nagios monitoring to check for
problems impacting the websockets sending code path, which is what all
web users use.

puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_send_receive_time

@@ -53,6 +53,11 @@ parser.add_option('--insecure',
 parser.add_option('--munin',
                   dest='munin',
                   action='store_true')
+
+parser.add_option('--websocket',
+                  dest='websocket',
+                  action='store_true')
+
 (options, args) = parser.parse_args()
 
 if not options.nagios and not options.munin:
@@ -83,6 +88,7 @@ os.environ['DJANGO_SETTINGS_MODULE'] = "zproject.settings"
 django.setup()
 
 from zerver.models import get_user_profile_by_email
+from zerver.tornado.websocket_client import WebsocketClient
 from django.conf import settings
 
 states = {
@@ -120,6 +126,11 @@ def get_zulips():
         last_event_id = max(last_event_id, int(event['id']))
     return [event['message'] for event in res['events']]
 
+
+def send_message_via_websocket(websocket_client, recepient_email, content):
+    # type: (WebsocketClient, str, str) -> None
+    websocket_client.send_message('website', 'private', 'no topic', "", recepient_email, content)
+
 if "staging" in options.site and settings.NAGIOS_STAGING_SEND_BOT is not None and \
         settings.NAGIOS_STAGING_RECEIVE_BOT is not None:
     sender = get_user_profile_by_email(settings.NAGIOS_STAGING_SEND_BOT)
@@ -154,12 +165,19 @@ except Exception:
 msg_to_send = str(random.getrandbits(64))
 time_start = datetime.datetime.now()
 
-send_zulip(zulip_sender, {
-    "type": 'private',
-    "content": msg_to_send,
-    "subject": "time to send",
-    "to": recipient.email,
-    })
+if options.websocket:
+    client = WebsocketClient(host_url=options.site, sockjs_url='/sockjs/366/v8nw22qe/websocket',
+                             run_on_start=send_message_via_websocket, sender_email=sender.email,
+                             recepient_email=recipient.email, content=msg_to_send,
+                             validate_ssl=not options.insecure)
+    client.run()
+else:
+    send_zulip(zulip_sender, {
+        "type": 'private',
+        "content": msg_to_send,
+        "subject": "time to send",
+        "to": recipient.email,
+        })
 
 msg_content = [] # type: List[str]
 

puppet/zulip_ops/files/cron.d/check_send_receive_time

@@ -4,4 +4,4 @@ USER=zulip
 STATE_FILE=/var/lib/nagios_state/check_send_receive_state
 
 * * * * * zulip /usr/lib/nagios/plugins/zulip_app_frontend/check_send_receive_time --nagios --site=https://$(/home/zulip/deployments/current/scripts/get-django-setting NAGIOS_BOT_HOST) >/dev/null
-
+* * * * * zulip /usr/lib/nagios/plugins/zulip_app_frontend/check_send_receive_time --nagios --websocket --site=https://$(/home/zulip/deployments/current/scripts/get-django-setting NAGIOS_BOT_HOST) >/dev/null