Feature/Add Discord Alert Destination (getredash#6106)

* Add discord webhook

* Fix icon

* Boto3 dependency

* Add unit test for Discord webhook

* Add suggestions

* Apply suggestions from code review

Co-authored-by: Jun <junnplus@gmail.com>

* Misunderstood suggestion )

* Add suggestions

* Apply suggestions from code review

Co-authored-by: Jun <junnplus@gmail.com>

* Fix test

* Fix variables in strings

* Fix formatting using our pre-commit hook

---------

Co-authored-by: Jun <junnplus@gmail.com>
Co-authored-by: Justin Clift <justin@postgresql.org>

redash/destinations/discord.py

@@ -0,0 +1,70 @@
+import logging
+
+import requests
+
+from redash.destinations import BaseDestination, register
+from redash.models import Alert
+from redash.utils import json_dumps
+
+colors = {
+    # Colors are in a Decimal format as Discord requires them to be Decimals for embeds
+    Alert.OK_STATE: "2600544",  # Green Decimal Code
+    Alert.TRIGGERED_STATE: "12597547",  # Red Decimal Code
+    Alert.UNKNOWN_STATE: "16776960",  # Yellow Decimal Code
+}
+
+
+class Discord(BaseDestination):
+    @classmethod
+    def configuration_schema(cls):
+        return {
+            "type": "object",
+            "properties": {"url": {"type": "string", "title": "Discord Webhook URL"}},
+            "secret": ["url"],
+            "required": ["url"],
+        }
+
+    @classmethod
+    def icon(cls):
+        return "fa-discord"
+
+    def notify(self, alert, query, user, new_state, app, host, options):
+        # Documentation: https://birdie0.github.io/discord-webhooks-guide/discord_webhook.html
+        fields = [
+            {
+                "name": "Query",
+                "value": f"{host}/queries/{query.id}",
+                "inline": True,
+            },
+            {
+                "name": "Alert",
+                "value": f"{host}/alerts/{alert.id}",
+                "inline": True,
+            },
+        ]
+        if alert.options.get("custom_body"):
+            fields.append({"name": "Description", "value": alert.options["custom_body"]})
+        if new_state == Alert.TRIGGERED_STATE:
+            if alert.options.get("custom_subject"):
+                text = alert.options["custom_subject"]
+            else:
+                text = f"{alert.name} just triggered"
+        else:
+            text = f"{alert.name} went back to normal"
+        color = colors.get(new_state)
+        payload = {"content": text, "embeds": [{"color": color, "fields": fields}]}
+        headers = {"Content-Type": "application/json"}
+        try:
+            resp = requests.post(
+                options.get("url"),
+                data=json_dumps(payload),
+                headers=headers,
+                timeout=5.0,
+            )
+            if resp.status_code != 200 and resp.status_code != 204:
+                logging.error(f"Discord send ERROR. status_code => {resp.status_code}")
+        except Exception as e:
+            logging.exception("Discord send ERROR: %s", e)
+
+
+register(Discord)

redash/settings/__init__.py

@@ -355,6 +355,7 @@ def email_server_is_configured():
     "redash.destinations.email",
     "redash.destinations.slack",
     "redash.destinations.webhook",
+    "redash.destinations.discord",
     "redash.destinations.mattermost",
     "redash.destinations.chatwork",
     "redash.destinations.pagerduty",

tests/handlers/test_destinations.py

@@ -1,4 +1,8 @@
-from redash.models import NotificationDestination
+import json
+from unittest import mock
+
+from redash.destinations.discord import Discord
+from redash.models import Alert, NotificationDestination
 from tests import BaseTestCase
 
 
@@ -86,3 +90,54 @@ def test_post(self):
         d = NotificationDestination.query.get(d.id)
         self.assertEqual(d.name, data["name"])
         self.assertEqual(d.options["url"], data["options"]["url"])
+
+
+def test_discord_notify_calls_requests_post():
+    alert = mock.Mock(spec_set=["id", "name", "options", "render_template"])
+    alert.id = 1
+    alert.name = "Test Alert"
+    alert.options = {
+        "custom_subject": "Test custom subject",
+        "custom_body": "Test custom body",
+    }
+    alert.render_template = mock.Mock(return_value={"Rendered": "template"})
+    query = mock.Mock()
+    query.id = 1
+
+    user = mock.Mock()
+    app = mock.Mock()
+    host = "https://localhost:5000"
+    options = {"url": "https://discordapp.com/api/webhooks/test"}
+
+    new_state = Alert.TRIGGERED_STATE
+    destination = Discord(options)
+
+    with mock.patch("redash.destinations.discord.requests.post") as mock_post:
+        mock_response = mock.Mock()
+        mock_response.status_code = 204
+        mock_post.return_value = mock_response
+
+        destination.notify(alert, query, user, new_state, app, host, options)
+
+        expected_payload = {
+            "content": "Test custom subject",
+            "embeds": [
+                {
+                    "color": "12597547",
+                    "fields": [
+                        {"name": "Query", "value": f"{host}/queries/{query.id}", "inline": True},
+                        {"name": "Alert", "value": f"{host}/alerts/{alert.id}", "inline": True},
+                        {"name": "Description", "value": "Test custom body"},
+                    ],
+                }
+            ],
+        }
+
+        mock_post.assert_called_once_with(
+            "https://discordapp.com/api/webhooks/test",
+            data=json.dumps(expected_payload),
+            headers={"Content-Type": "application/json"},
+            timeout=5.0,
+        )
+
+        assert mock_response.status_code == 204