Render the payload_url of the Webhook with Jinja2

- Update markdown documentation
- Expand on the help text for the Webhook model

netbox/extras/models/models.py

@@ -68,7 +68,8 @@ class Webhook(ChangeLoggedModel):
     payload_url = models.CharField(
         max_length=500,
         verbose_name='URL',
-        help_text="A POST will be sent to this URL when the webhook is called."
+        help_text='This URL will be called using the HTTP method defined when the webhook is called. '
+                  'Jinja2 template processing is supported with the same context as the request body.'
     )
     enabled = models.BooleanField(
         default=True
@@ -176,6 +177,12 @@ class Webhook(ChangeLoggedModel):
         else:
             return json.dumps(context, cls=JSONEncoder)
 
+    def render_payload_url(self, context):
+        """
+        Render the payload URL.
+        """
+        return render_jinja2(self.payload_url, context)
+
 
 @extras_features('webhooks', 'export_templates')
 class CustomLink(ChangeLoggedModel):

netbox/extras/webhooks_worker.py

@@ -67,7 +67,7 @@ def process_webhook(webhook, model_name, event, data, snapshots, timestamp, user
     # Prepare the HTTP request
     params = {
         'method': webhook.http_method,
-        'url': webhook.payload_url,
+        'url': webhook.render_payload_url(context),
         'headers': headers,
         'data': body.encode('utf8'),
     }