Re-implement FCM relay after introducing firebase (#1121)

This PR changes how `FCMRelayView` handles push notifications from OSS
instances, also changing how the mobile app backend sends push
notifications.

engine/apps/mobile_app/fcm_relay.py

@@ -1,29 +1,72 @@
-# from firebase_admin.messaging import Message
-# from fcm_django.models import FCMDevice
+import logging
+
+from fcm_django.models import FCMDevice
+from firebase_admin.messaging import APNSConfig, APNSPayload, Aps, ApsAlert, CriticalSound, Message
 from rest_framework import status
 from rest_framework.response import Response
 from rest_framework.views import APIView
 
-REQUIRED_FIELDS = {"registration_ids", "notification", "data"}
+logger = logging.getLogger(__name__)
+logger.setLevel(logging.DEBUG)
 
 
-# TODO: update thie
 class FCMRelayView(APIView):
+    # TODO: use public API authentication (then it would be required to connect to a cloud instance to use the app)
+    authentication_classes = []
+    permission_classes = []
+
     def post(self, request):
         """
-        This view accepts requests from OSS instances of Grafana OnCall and forwards these requests to FCM.
-        Requests will be sent with the FCM_API_KEY configured in server settings
-        (see PUSH_NOTIFICATIONS_SETTINGS in settings/base.py)
+        This view accepts push notifications from OSS instances and forwards these requests to FCM.
+        Requests to this endpoint come from OSS instances: apps.mobile_app.tasks.send_push_notification_to_fcm_relay
         """
 
-        if not REQUIRED_FIELDS.issubset(request.data.keys()):
+        try:
+            token = request.data["token"]
+            data = request.data["data"]
+        except KeyError:
             return Response(status=status.HTTP_400_BAD_REQUEST)
 
-        # registration_ids = request.data["registration_ids"]
-        # data = {
-        #     **request.data["data"],
-        #     **request.data["notification"],
-        # }
+        message = Message(token=token, data=data, apns=get_apns(request.data))
 
-        # return FCMDevice.objects.send_message(Message(), False, ["registration_ids"])
-        return "TODO:"
+        logger.debug(f"Sending message to FCM: {message}")
+        result = FCMDevice(registration_id=token).send_message(message)
+        logger.debug(f"FCM response: {result}")
+
+        return Response(status=status.HTTP_200_OK)
+
+
+def get_apns(data):
+    """
+    Create APNSConfig object from JSON payload from OSS instance.
+    """
+    aps = data.get("apns", {}).get("payload", {}).get("aps", {})
+    if not aps:
+        return None
+
+    thread_id = aps.get("thread-id")
+    badge = aps.get("badge")
+
+    alert = aps.get("alert")
+    if isinstance(alert, dict):
+        alert = ApsAlert(**alert)
+
+    sound = aps.get("sound")
+    if isinstance(sound, dict):
+        sound = CriticalSound(**sound)
+
+    # remove all keys from "aps" so it can be used for custom_data
+    for key in ["thread-id", "badge", "alert", "sound"]:
+        aps.pop(key, None)
+
+    return APNSConfig(
+        payload=APNSPayload(
+            aps=Aps(
+                thread_id=thread_id,
+                badge=badge,
+                alert=alert,
+                sound=sound,
+                custom_data=aps,
+            )
+        )
+    )

engine/apps/mobile_app/tasks.py

@@ -1,3 +1,7 @@
+import json
+import logging
+
+import requests
 from celery.utils.log import get_task_logger
 from django.conf import settings
 from fcm_django.models import FCMDevice
@@ -6,10 +10,12 @@ from firebase_admin.messaging import APNSConfig, APNSPayload, Aps, ApsAlert, Cri
 from apps.alerts.models import AlertGroup
 from apps.mobile_app.alert_rendering import get_push_notification_message
 from apps.user_management.models import User
+from common.api_helpers.utils import create_engine_url
 from common.custom_celery_tasks import shared_dedicated_queue_retry_task
 
 MAX_RETRIES = 1 if settings.DEBUG else 10
 logger = get_task_logger(__name__)
+logger.setLevel(logging.DEBUG)
 
 
 @shared_dedicated_queue_retry_task(autoretry_for=(Exception,), retry_backoff=True, max_retries=MAX_RETRIES)
@@ -71,8 +77,6 @@ def notify_user_async(user_pk, alert_group_pk, notification_policy_pk, critical)
 
     alert_body = f"Status: {status_verbose}, alerts: {alerts_count_str}"
 
-    # TODO: we should update this to check if FCM_RELAY is set and conditionally make a call here..
-
     message = Message(
         token=device_to_notify.registration_id,
         data={
@@ -109,10 +113,25 @@ def notify_user_async(user_pk, alert_group_pk, notification_policy_pk, critical)
         ),
     )
 
-    logger.info(f"Sending push notification with message: {message}; thread-id: {thread_id};")
+    logger.debug(f"Sending push notification with message: {message}; thread-id: {thread_id};")
 
-    fcm_response = device_to_notify.send_message(message)
+    if settings.LICENSE == settings.OPEN_SOURCE_LICENSE_NAME:
+        response = send_push_notification_to_fcm_relay(message)
+        logger.debug(f"FCM relay response: {response}")
+    else:
+        response = device_to_notify.send_message(message)
+        # NOTE: we may want to further handle the response from FCM, but for now lets simply log it out
+        # https://firebase.google.com/docs/cloud-messaging/http-server-ref#interpret-downstream
+        logger.debug(f"FCM response: {response}")
 
-    # NOTE: we may want to further handle the response from FCM, but for now lets simply log it out
-    # https://firebase.google.com/docs/cloud-messaging/http-server-ref#interpret-downstream
-    logger.info(f"FCM response was: {fcm_response}")
+
+def send_push_notification_to_fcm_relay(message):
+    """
+    Send push notification to FCM relay on cloud instance: apps.mobile_app.fcm_relay.FCMRelayView
+    """
+    url = create_engine_url("mobile_app/v1/fcm_relay", override_base=settings.GRAFANA_CLOUD_ONCALL_API_URL)
+
+    response = requests.post(url, json=json.loads(str(message)))
+    response.raise_for_status()
+
+    return response