As of April 10, 2018, Google has deprecated the Google Cloud Messaging (GCM) service. The GCM server and client APIs are deprecated and will be removed as of April 11, 2019. Migrate GCM apps to Firebase Cloud Messaging (FCM), which inherits the reliable and scalable GCM infrastructure, plus many new features.
The Mattermost Push Notification Service version 5.8+ uses FCM to send Push notifications for Android.
Go to the Firebase Console and select the project you’ve created. Once in the dashboard, go to the project settings and select CLOUD MESSAGING.
Look for the value of the Server Key and copy it.
Open the mattermost-push-proxy.json file in the
mattermost-push-proxy/config directory and replace the value for the “AndroidApiKey” setting with the Server Key you just copied.
Restart your Mattermost Push Notification Service, and notifications should be sent using FCM.
$ sudo service mattermost-push-proxy restart
Test push notifications are being delivered as expected.
Make sure your firewall allows connections to the Firebase servers
fcm-xmpp.googleapis.com on ports:
80 TCP HTTP client connection 443 TCP HTTP client connection over SSL 5222 TCP XMPP client connection 5223 TCP XMPP client connection over SSL