Add Remote Settings to heartbeat monitoring

src/olympia/amo/monitors.py

@@ -197,3 +197,24 @@ def database():
                 monitor_log.critical(status)
 
     return status, None
+
+
+def remotesettings():
+    # check Remote Settings connection
+
+    from olympia.lib.remote_settings import RemoteSettings
+    from olympia.constants.blocklist import REMOTE_SETTINGS_COLLECTION_MLBF
+
+    client = RemoteSettings(
+        settings.REMOTE_SETTINGS_WRITER_BUCKET,
+        REMOTE_SETTINGS_COLLECTION_MLBF,
+    )
+
+    status = ''
+    try:
+        client.heartbeat()
+    except Exception as e:
+        status = f'Failed to contact Remote Settings server: {e}'
+        monitor_log.critical(status)
+
+    return status, None

src/olympia/amo/tests/test_monitor.py

@@ -1,3 +1,5 @@
+import json
+
 from django.conf import settings
 from django.test.utils import override_settings
 
@@ -77,3 +79,23 @@ def test_database(self):
             status, result = monitors.database()
         assert status == ''
         assert result is None
+
+    def test_remotesettings_success(self):
+        responses.add(
+            responses.GET,
+            f'{settings.REMOTE_SETTINGS_WRITER_URL}__heartbeat__',
+            status=200,
+            body=json.dumps({'check': True}),
+        )
+        obtained, _ = monitors.remotesettings()
+        assert obtained == ''
+
+    def test_remotesettings_fail(self):
+        responses.add(
+            responses.GET,
+            f'{settings.REMOTE_SETTINGS_WRITER_URL}__heartbeat__',
+            status=503,
+            body=json.dumps({'check': False}),
+        )
+        obtained, _ = monitors.remotesettings()
+        assert obtained == 'boom'

src/olympia/amo/views.py

@@ -44,6 +44,7 @@ def heartbeat(request):
         'rabbitmq',
         'signer',
         'database',
+        'remotesettings',
     ]
 
     for check in checks:

src/olympia/lib/remote_settings.py

@@ -42,6 +42,12 @@ def headers(self):
         b64 = b64encode(f'{self.username}:{self.password}'.encode()).decode()
         return {'Content-Type': 'application/json', 'Authorization': f'Basic {b64}'}
 
+    def heartbeat(self):
+        url = f'{settings.REMOTE_SETTINGS_WRITER_URL}__heartbeat__'
+        response = requests.get(url, headers=self.headers)
+        response.raise_for_status()
+        return response.json()
+
     def setup_test_server_auth(self):
         # check if the user already exists in remote setting's accounts
         host = settings.REMOTE_SETTINGS_WRITER_URL