问题
I know how to send messages from Firebase cloud messaging portal to an android device. But my server runs on Google Cloud, I do gcloud app deploy from my local machine and the app logic gets deployed on Google Cloud. Now, I want to send notifications, based on the data stored as Entities in GCP Datastore, to an Android App.
Notification messages can be sent from Firestore-Cloud Messaging portal to an Android device, if I could harness this Firestore Cloud Messaging API in my GCP logic, then my problem will be solved.
I'm trying to look for any examples or POC's.
回答1:
you can use Cloud Functions to add such custom functionality... for example: https://android.jlelse.eu/serverless-notifications-with-cloud-functions-for-firebase-685d7c327cd4
and there are Cloud Datastore Callbacks, which can be used as event triggers. most relevant for Cloud Functions might be the Google Cloud Datastore Node.js Client - in order to connect to the Datastore. here's one of my examples, it is written in AppScript (similar to Node.js), which also connects to a Cloud Datastore, with the service account JSON loaded from Google Drive.
however, in this case the Datastore would need to subsequently trigger an HTTP Trigger or Pub/Sub Trigger and the code behind that trigger could get more data from the Datastore or directly send the Firebase notification.
in Cloud Function there are just triggers for Cloud Storage, while the Pub/Sub (publish/subscribe) triggers can be used for just anything. The Datastore would need to publish whatever event (add/edit/update/delete) - while a Cloud Functions script would need to subscribe these events.
using Firebase as backend might be less effort, because data-change events/triggers are being supported out-of-the-box, without any HTTP interaction or Pub/Sub communication involved.
来源：https://stackoverflow.com/questions/51451436/how-do-i-send-notifications-from-google-cloudgcp-via-firebase-to-an-android-ap