Agnostic Push Notification Microservice

Welcome to our newest open-source software project - an agnostic push notification microservice! This service is developed using AWS Cloud Development Kit (CDK) and JavaScript, offering a highly flexible and efficient solution for managing push notifications in mobile applications.

This project is developed by HyperSense Software and it is distributed under an MIT License.

Our agnostic push notification microservice leverages the power of AWS services to provide a seamless experience. At its core, the API Gateway exposes endpoints that enable mobile apps to register Firebase tokens. With the help of AWS Cognito, secure access is ensured through the authorization of incoming requests.

This microservice is designed to handle various aspects of push notifications, including associating user IDs with their respective Firebase tokens, sending push notifications, maintaining read counts, managing notification lists, and offering other functionalities aimed at improving the push notification experience.

Another vital element of the microservice is an SQS queue that allows other microservices to send push notifications to users. By saving sent messages and maintaining logs using DynamoDB, the push notification microservice offers a reliable and efficient method for tracking notifications and ensuring smooth operation.

Microservice high-level diagram

Please find below a high-level diagram outlining the main components of this node.js microservice.

Setup and deploy

Some resources will need to be created, while others be provided

Firebase project

You will need to create a firebase project and generate a private key for it. It will be similar to:

{
  "type": "service_account",
  "project_id": "<project_id>",
  "private_key_id": "<private_key_id>",
  "private_key": "<private_key>",
  "client_email": "<client_email>",
  "client_id": "<client_id>",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "<client_x509_cert_url>"
}

AWS resources

Need to be provided

The following must be created manually or by other systems

• Secret Manager named AgnosticPushNotificationsSecret
  • must contain the key FIREBASE_KEY with the value set as the json key above
• User Pool

Will be created during deploy

The following will be created during deployment

• ApiGateway: AgnosticPushNotificationsEndpoint
• DynamoDb tables: agnostic_push_devices, agnostic_push_notifications, agnostic_push_notifications_log
• Lambda layer: AgnosticPushMicroserviceLayer
• Lambdas
• CloudWatch Log Groups
• Input and Output Queues

Environment variables for deployment

Authorizer pool

USER_POOL_ID=<enter your id>

Custom domain name setup

If they are not set the deploy will generate a warning, but will not fail. Certificate must be on the same region as the gateway. If you have a different setup, please make sure to change the gateway to EDGE instead of REGIONAL.

HOSTED_ZONE_ID=<enter your zone id>
ZONE_NAME=<your zone name>
CERTIFICATE_ARN=<certificate arn>
API_DOMAIN=<api domain/subdomain>

#Samples

Sample messages for queues

Stack variables

Setup TTL for logs and messages, this will remove messages after TTL expires APN_MESSAGE_DEFAULT_TTL preset to 30 * 24 * 60 * 60 sAPN_MESSAGE_LOG_DEFAULT_TTL preset to 86400

Messages for queues

Sending a notification

Templates are part of the code, check Template Param expiresAt is optional, if not sent default will be used.Input queue sample message:

{
    "requestId":"sample",
    "requestType":"send_message",
    "requestParams" : {
        "userId" :"4368d4ff-e8f5-4788-8e66-30418eafa5af",
        "templateId" : "hello_world",
        "expiresAt" : "1680268046.989",
        "templateParams" : {"USER_NAME":"Jane"}
    }
}

Output queue sample message

{
  "requestId":"sample2",
  "response":{
    "type":"default",
    "userId":"4368d4ff-e8f5-4788-8e66-30418eafa5af",
    "id":"94f11d92-9ecf-4cf8-8b3e-901e8227d8ac",
    "notificationPayload":{
      "userId":"4368d4ff-e8f5-4788-8e66-30418eafa5af",
      "templateId":"hello_world",
      "templateParams":{"USER_NAME":"Mirela"},
      "type":"default"
    },
    "texts":{
      "ios":{"title":"Hello Jane","body":"Glad to see an iOS fan"},
      "android":{"title":"Hello Jane","body":"I like android better"}
    },
    "createdAt":"1680268046.989",
    "status":"new",
    "systemStatus":"new"
  }
}

Getting a notification

Input queue sample message to get a notification, useful to check status

{
  "requestId":"sample_get",
  "requestType":"get_message",
  "requestParams" : {
    "notificationId":"bafb3597-6679-4fff-8928-18a17fede183"
  }
}

Output queue sample message to get a notification

{"requestId":"sample_get","response":{"id":"bafb3597-6679-4fff-8928-18a17fede183","createdAt":"1680267880.931","userId":"4368d4ff-e8f5-4788-8e66-30418eafa5af","status":"read","systemStatus":"new","notificationPayload":{"userId":"4368d4ff-e8f5-4788-8e66-30418eafa5af","templateId":"hello_world","templateParams":{"USER_NAME":"Mirela"},"type":"default"},"texts":{"ios":{"title":"Hello Mirela","body":"Glad to see an iOS fan"},"android":{"title":"Hello Mirela","body":"I like android better"}},"type":"default"}}

Removing a user

Input queue sample message to remove a user, will remove the devices for that user

{
  "requestId":"sample_remove",
  "requestType":"remove_user",
  "requestParams" : {
    "userId":"4368d4ff-e8f5-4788-8e66-30418eafa5af"
  }
}

Output queue sample message to get a notification