GET webhooks support custom headers too. Can override the User-Agent header.

hc/api/models.py

@@ -311,8 +311,8 @@ class Channel(models.Model):
             return parts[0]
 
         doc = json.loads(self.value)
-        return doc["url_down"]
-        
+        return doc.get("url_down")
+
 
     @property
     def url_up(self):
@@ -322,7 +322,7 @@ class Channel(models.Model):
             return parts[1] if len(parts) > 1 else ""
 
         doc = json.loads(self.value)
-        return doc["url_up"]
+        return doc.get("url_up")
 
     @property
     def post_data(self):
@@ -332,16 +332,16 @@ class Channel(models.Model):
             return parts[2] if len(parts) > 2 else ""
 
         doc = json.loads(self.value)
-        return doc["post_data"]
+        return doc.get("post_data")
 
     @property
     def headers(self):
         assert self.kind == "webhook"
         if not self.value.startswith("{"):
-            return ""
+            return {}
 
         doc = json.loads(self.value)
-        return doc["headers"]
+        return doc.get("headers", {})
 
     @property
     def slack_team(self):

hc/api/tests/test_notify.py

@@ -147,43 +147,73 @@ class NotifyTestCase(BaseTestCase):
 
     @patch("hc.api.transports.requests.request")
     def test_webhooks_handle_json_value(self, mock_request):
-        self._setup_data("webhook", '{"url_down": "http://foo.com", '
-            '"url_up": "", "post_data": "", "headers": ""}')
+        definition = {"url_down": "http://foo.com"}
+        self._setup_data("webhook", json.dumps(definition))
         self.channel.notify(self.check)
 
-        headers = {
-            "User-Agent": "healthchecks.io"
-        }
+        headers = {"User-Agent": "healthchecks.io"}
         mock_request.assert_called_with(
-            "get", "http://foo.com", headers=headers,
-            timeout=5)
+            "get", "http://foo.com", headers=headers, timeout=5)
 
     @patch("hc.api.transports.requests.request")
     def test_webhooks_handle_json_up_event(self, mock_request):
-        self._setup_data("webhook", '{"url_down": "", '
-            '"url_up": "http://bar", "post_data": "", "headers": ""}', status="up")
+        definition = {"url_up": "http://bar"}
+
+        self._setup_data("webhook", json.dumps(definition), status="up")
+        self.channel.notify(self.check)
+
+        headers = {"User-Agent": "healthchecks.io"}
+        mock_request.assert_called_with(
+            "get", "http://bar", headers=headers, timeout=5)
+
+    @patch("hc.api.transports.requests.request")
+    def test_webhooks_handle_post_headers(self, mock_request):
+        definition = {
+            "url_down": "http://foo.com",
+            "post_data": "data",
+            "headers": {"Content-Type": "application/json"}
+        }
+
+        self._setup_data("webhook", json.dumps(definition))
         self.channel.notify(self.check)
 
         headers = {
-            "User-Agent": "healthchecks.io"
+            "User-Agent": "healthchecks.io",
+            "Content-Type": "application/json"
         }
         mock_request.assert_called_with(
-            "get", "http://bar", headers=headers,
-            timeout=5)
+            "post", "http://foo.com", data=b"data", headers=headers, timeout=5)
 
     @patch("hc.api.transports.requests.request")
-    def test_webhooks_handle_headers(self, mock_request):
-        self._setup_data("webhook", '{"url_down": "http://foo.com", '
-            '"url_up": "", "post_data": "data", '
-            '"headers": {"Content-Type": "application/json"}}')
+    def test_webhooks_handle_get_headers(self, mock_request):
+        definition = {
+            "url_down": "http://foo.com",
+            "headers": {"Content-Type": "application/json"}
+        }
+
+        self._setup_data("webhook", json.dumps(definition))
         self.channel.notify(self.check)
 
         headers = {
-            "User-Agent": "healthchecks.io", 
+            "User-Agent": "healthchecks.io",
             "Content-Type": "application/json"
         }
         mock_request.assert_called_with(
-            "post", "http://foo.com", data=b"data", headers=headers, timeout=5)
+            "get", "http://foo.com", headers=headers, timeout=5)
+
+    @patch("hc.api.transports.requests.request")
+    def test_webhooks_allow_user_agent_override(self, mock_request):
+        definition = {
+            "url_down": "http://foo.com",
+            "headers": {"User-Agent": "My-Agent"}
+        }
+
+        self._setup_data("webhook", json.dumps(definition))
+        self.channel.notify(self.check)
+
+        headers = {"User-Agent": "My-Agent"}
+        mock_request.assert_called_with(
+            "get", "http://foo.com", headers=headers, timeout=5)
 
     def test_email(self):
         self._setup_data("email", "[email protected]")

hc/api/transports.py

@@ -80,11 +80,11 @@ class HttpTransport(Transport):
     def _request(cls, method, url, **kwargs):
         try:
             options = dict(kwargs)
+            options["timeout"] = 5
             if "headers" not in options:
                 options["headers"] = {}
-
-            options["timeout"] = 5
-            options["headers"]["User-Agent"] = "healthchecks.io"
+            if "User-Agent" not in options["headers"]:
+                options["headers"]["User-Agent"] = "healthchecks.io"
 
             r = requests.request(method, url, **options)
             if r.status_code not in (200, 201, 204):
@@ -96,10 +96,10 @@ class HttpTransport(Transport):
             return "Connection failed"
 
     @classmethod
-    def get(cls, url):
+    def get(cls, url, **kwargs):
         # Make 3 attempts--
         for x in range(0, 3):
-            error = cls._request("get", url)
+            error = cls._request("get", url, **kwargs)
             if error is None:
                 break
 
@@ -166,14 +166,12 @@ class Webhook(HttpTransport):
         assert url
 
         url = self.prepare(url, check, urlencode=True)
+        headers = self.channel.headers
         if self.channel.post_data:
             payload = self.prepare(self.channel.post_data, check)
-            headers = {}
-            if self.channel.headers:
-                headers = self.channel.headers
             return self.post(url, data=payload.encode("utf-8"), headers=headers)
         else:
-            return self.get(url)
+            return self.get(url, headers=headers)
 
 
 class Slack(HttpTransport):