Push Notification Relay Server for Frappe Apps

This repo was created to enable push notifications for Frappe Apps such as Raven.

Getting Started

To be able to run this application, you will need to do the following:

1. Clone this project and create a virtual environment python -m venv env
2. Install all requirements pip install -r requirements.txt
3. Create a Firebase Project & get Service Account credentials Link
4. Run this command on the shell

export GOOGLE_APPLICATION_CREDENTIALS="/home/frappe/relay-server/{service-account-file_name}.json"

6. Follow Register you app under Step 1 given in the Firebase documentation and obtain the FIREBASE_CONFIG JSON object. Save it to my_secrets.py.
7. Follow this StackOverflow Link to generate a VAPID key. Save it to my_secrets.py
8. Generate API_KEY & API_SECRET and add the API_SECRET value to the my_secrets.py.
9. Finally, your my_secrets.py should like this

API_SECRET = 'tIUAGguQH-xajbkcjsd-lsd'
VAPID_PUBLIC_KEY = "Bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
FIREBASE_CONFIG = {
  "apiKey": "AIzaSyC3UVxbCkUv3l4PpyWkQZGEuwOds76sdUgk0",
  "authDomain": "xxxxxxxx-frappe.firebaseapp.com",
  "projectId": "xxxxxxxxx-frappe",
  "storageBucket": "xxxxxxxxx-frappe.appspot.com",
  "messagingSenderId": "815115xxx703",
  "appId": "1:815115xxx703:web:e89fcdadfcf8df09e4852",
  "measurementId": "G-XXXXXXXXXG"
}

10. Change the USER_DEVICE_MAP key values to {project_name}_{site_name} where project_name could be raven or hrms & site_name as your site name while setting up the Frappe bench.
11. Run the application
12. Add the API_SECRET & API_KEY in ERPNext Push Notification settings and then enable the Push Notification Relay option.

Running the Application

gunicorn app:app -c gunicorn.conf.py

Run a Systemd Service

• Create a Systemd service file at /etc/systemd/system/push-relay.service and copy the following and replace the paths/filenames accordingly :

# /etc/systemd/system/push-relay.service
[Unit]
Description=Gunicorn instance to server Frappe Push Notification Relay Server
After=network.target

[Service]
User=frappe
Group=www-data
WorkingDirectory=/home/frappe/relay-server
Environment="PATH=/home/frappe/relay-server/env/bin"
Environment="GOOGLE_APPLICATION_CREDENTIALS=/home/frappe/relay-server/{service-account-file_name}.json"
ExecStart=/home/frappe/relay-server/env/bin/gunicorn app:app -c /home/frappe/relay-server/gunicorn.conf.py

[Install]
WantedBy=multi-user.target

• Run the following commands

  sudo systemctl daemon-reload
  sudo systemctl enable push-relay
  sudo systemctl start push-relay

Fix CORS issue [ localhost ] :

• In case you are running Frappe instance on localhost, then perform the following steps to avoid CORS issues

  • Run the following commands

     pip install flask-cors

  • app.py [add line 8 & 10]

      7    from my_secrets import API_SECRET, FIREBASE_CONFIG, VAPID_PUBLIC_KEY, BADGE_ICON
    + 8    from flask_cors import CORS
    
      9    app = Flask(__name__)
    + 10   CORS(app, resources={r"/*": {"origins": "*"}})  # This will allow all origins
    
      11   firebase_app = firebase_admin.initialize_app()
      12   basic_auth = HTTPBasicAuth()

  • firebase_admin/_messaging_encoder.py [ comment line : 507, 508 ]

      506    link = result.get('link')
    - 507    # if link is not None and not link.startswith('https://'):
    - 508        # raise ValueError('WebpushFCMOptio ns.link must be a HTTPS URL.') 
      509    return result

  • Restart bench and gunicorn server