This part of the backend handles device push notifications for registered users. It consumes messages from RabbitMQ, looks up user device tokens from a MySQL database, and sends notifications via Expo's API. Failed deliveries are retried or sent to a dead-letter queue.

Requirements

Python 3.12+
MySQL database
RabbitMQ
Python packages from requirements.txt

Configuration

Environment variables:

LOG_LEVEL (DEBUG, INFO, WARNING, ERROR, CRITICAL)
RABBITMQ_URL
MYSQL_HOST, MYSQL_USER, MYSQL_PASSWORD, MYSQL_DATABASE
API_ENDPOINT (Expo push API)

Metrics

Metrics are exposed on port 9000 for Prometheus, including:

MSG_PUBLISHED
MSG_FAILED
MSG_RETRY
Queue sizes