Notification service

System diagram

Description

Notification service allows you to send notifications to different channels.

Channels implemented:

1. SMS (implemented Twilio)
2. Email (implemented Mailjet)
3. Slack

The service is open for extensibility, and adding a new channel is a straightforward process, as well as adding implementations of providers (gateways).

The service is built on top of BeeORM, MySQL, Redis and Redis Streams. It guarantees at-least-once delivery due to the nature of Redis Streams - search for at-least-once.

Configuration

The service config file path is: ./config/config.yaml

How to run

1. cd docker ; ./build.sh ; cd ..
2. open your favorite MySQL GUI client and create 2 empty databases: "notification" and "notification_test" - the rest will be taken care of by the ORM when you start the apps
3. make consumer - this cron will consume notification events and send them, you can scale it using 2 approaches:
   • runmake consumer in new terminals
   • by running following code in consumer main.go in a for loop 5-10-20 times.

	consumerRunner.RunConsumerMany(
		consumerbeeorm.NotificationsDirtyConsumer(smsService, emailService, slackService),
		queue.OrmDirtyNotificationEntity,
		100,
	)

4. make notification-api - it fires up an HTTP server on 8080, you can change the port in the config file
5. open swagger doc
6. send request to "POST /v1/notification/send-async" with the following body (or change it how you want)

Request body

sms   // if you want to test sms, you need to create account in twilio and put the api keys in the config file
email // if you want to test email, you need to create account in mailjet nad put the api keys in the config file
slack // if you want to test slack, you need to create an organization and configure a bot, then put the boy key in the config file

JSON

{
   "email": {
      "from": "string",
      "from_name": "string",
      "reply_to": "string",
      "subject": "string",
      "template_data": [
         {
            "key": "string",
            "value": "string"
         }
      ],
      "template_name": "string",
      "to": "string"
   },
   "slack_message": {
      "bot_name": "string",
      "channel_name": "string",
      "message": "string"
   },
   "sms": {
      "mobile_number": "string",
      "text": "string"
   }
}

Stopping an app

It's important to stop the consumer and the HTTP server correctly. They expect signal syscall.SIGINT or syscall.SIGTERM. The easiest way to stop an app is to go to the terminal its running and Ctrl+C. Don't close a terminal without stopping the application first, as this will cause the application to continue running inside the docker container, and you need to restart docker in order to stop it.

Testing

Run the tests: make test

Run the tests with coverage: make test-cover

Linter and formatting

Run make format-check

Regenerating swagger (every time you change an API)

Run make generate-notification-api-doc