Implement Pushover emergency alert cancellation when check goes up

CHANGELOG.md

@@ -1,6 +1,11 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## v1.25.0 - Unreleased
+
+### Improvements
+- Implement Pushover emergency alert cancellation when check goes up
+
 ## v1.24.1 - 2021-11-10
 
 ### Bug Fixes

hc/api/tests/test_notify_pushover.py

@@ -8,8 +8,10 @@ from django.utils.timezone import now
 from hc.api.models import Channel, Check, Notification, TokenBucket
 from hc.test import BaseTestCase
 
+API = "https://api.pushover.net/1"
 
-class NotifyTestCase(BaseTestCase):
+
+class NotifyPushoverTestCase(BaseTestCase):
     def _setup_data(self, value, status="down", email_verified=True):
         self.check = Check(project=self.project)
         self.check.status = status
@@ -24,24 +26,27 @@ class NotifyTestCase(BaseTestCase):
         self.channel.checks.add(self.check)
 
     @patch("hc.api.transports.requests.request")
-    def test_pushover(self, mock_post):
+    def test_it_works(self, mock_post):
         self._setup_data("123|0")
         mock_post.return_value.status_code = 200
 
         self.channel.notify(self.check)
-        assert Notification.objects.count() == 1
+        self.assertEqual(Notification.objects.count(), 1)
 
         args, kwargs = mock_post.call_args
+        self.assertEqual(args[1], API + "/messages.json")
+
         payload = kwargs["data"]
         self.assertIn("DOWN", payload["title"])
+        self.assertEqual(payload["tags"], self.check.unique_key)
 
     @patch("hc.api.transports.requests.request")
-    def test_pushover_up_priority(self, mock_post):
+    def test_it_supports_up_priority(self, mock_post):
         self._setup_data("123|0|2", status="up")
         mock_post.return_value.status_code = 200
 
         self.channel.notify(self.check)
-        assert Notification.objects.count() == 1
+        self.assertEqual(Notification.objects.count(), 1)
 
         args, kwargs = mock_post.call_args
         payload = kwargs["data"]
@@ -63,3 +68,21 @@ class NotifyTestCase(BaseTestCase):
         self.channel.notify(self.check)
         n = Notification.objects.first()
         self.assertEqual(n.error, "Rate limit exceeded")
+
+    @patch("hc.api.transports.requests.request")
+    def test_it_cancels_emergency_notification(self, mock_post):
+        self._setup_data("123|2|0", status="up")
+        mock_post.return_value.status_code = 200
+
+        self.channel.notify(self.check)
+        self.assertEqual(Notification.objects.count(), 1)
+
+        self.assertEqual(mock_post.call_count, 2)
+
+        cancel_args, cancel_kwargs = mock_post.call_args_list[0]
+        expected = "/receipts/cancel_by_tag/%s.json" % self.check.unique_key
+        self.assertEqual(cancel_args[1], API + expected)
+
+        up_args, up_kwargs = mock_post.call_args_list[1]
+        payload = up_kwargs["data"]
+        self.assertIn("UP", payload["title"])

hc/api/transports.py

@@ -380,25 +380,36 @@ class Pushbullet(HttpTransport):
 
 class Pushover(HttpTransport):
     URL = "https://api.pushover.net/1/messages.json"
+    CANCEL_TMPL = "https://api.pushover.net/1/receipts/cancel_by_tag/%s.json"
 
     def notify(self, check):
         pieces = self.channel.value.split("|")
-        user_key, prio = pieces[0], pieces[1]
+        user_key, down_prio = pieces[0], pieces[1]
+
         # The third element, if present, is the priority for "up" events
-        if len(pieces) == 3 and check.status == "up":
-            prio = pieces[2]
+        up_prio = down_prio
+        if len(pieces) == 3:
+            up_prio = pieces[2]
 
         from hc.api.models import TokenBucket
 
         if not TokenBucket.authorize_pushover(user_key):
             return "Rate limit exceeded"
 
+        # If down events have the emergency priority,
+        # send a cancel call first
+        if check.status == "up" and down_prio == "2":
+            url = self.CANCEL_TMPL % check.unique_key
+            payload = {"token": settings.PUSHOVER_API_TOKEN}
+            self.post(url, data=payload)
+
         others = self.checks().filter(status="down").exclude(code=check.code)
         # list() executes the query, to avoid DB access while
         # rendering a template
         ctx = {"check": check, "down_checks": list(others)}
         text = tmpl("pushover_message.html", **ctx)
         title = tmpl("pushover_title.html", **ctx)
+        prio = up_prio if check.status == "up" else down_prio
 
         payload = {
             "token": settings.PUSHOVER_API_TOKEN,
@@ -407,6 +418,7 @@ class Pushover(HttpTransport):
             "title": title,
             "html": 1,
             "priority": int(prio),
+            "tags": check.unique_key,
         }
 
         # Emergency notification