📣 NotifyGo - A Golang based notification service

A scalable, containerized microservice for sending notifications via Email, SMS, and WebSocket, built using GoFr – a Golang-based backend framework. This project is designed with clean 3-layer architecture and extensibility in mind.

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🚀 Features

• 📧 Email notifications via SMTP (MailHog)
• 📱 SMS notifications via Kannel gateway
• 🔔 WebSocket-based in-app alerts (real-time)
• 🧩 Dynamic message templating
• 🛠️ Unified API for triggering notifications
• 📦 Containerized with Docker Compose

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🛠 Setup Instructions

1. Clone the Repo

git clone https://github.com/Kake27/notifygo
cd notification-service

2. Set Environment Variables

Some default environmental variables have already been included in the code. In case any modification is needed, the environemental variables can be set as follows and used

SMTP_HOST=mailhog
SMTP_PORT=1025
SMTP_SENDER=[email protected]

KANNEL_URL=http://localhost:13013/cgi-bin/sendsms
KANNEL_USERNAME=test
KANNEL_PASSWORD=test123
KANNEL_SENDER=kannel

3. Start Services

Make sure docker is installed and then run

docker compose up --build

This will start:

• notification-service (your Go app)
• MailHog for email testing at localhost:8025
• GMail SMTP is used for sending the real emails
• Kannel for SMS delivery on port 13013

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📬 Sending Notifications

1. 📧 Send Email

POST /notify

{
  "type": "email",
  "to": "[email protected]",
  "subject": "This is a test subject",
  "message": "Hello from the Notification Service!"
}

MailHog will capture and display the email at: http://localhost:8025

2. 📱 Send SMS

POST /notify

{
  "type": "sms",
  "to": "+911234567890",
  "message": "This is a test SMS from the Notification Service!"
}

This uses the Kannel HTTP API behind the scenes for delivery. For now, the SMS is only being queued for delivery rather than actually being sent.

3. 🔔 Send Push Notification

POST /notify

{
  "type": "push",
  "to": "user123",
  "subject": "Important Update",
  "message": "You have a new notification!"
}

Note: The user must be connected via WebSocket to receive push notifications.

4. 🌐 WebSocket Connection

Connect to WebSocket endpoint for real-time push notifications:

ws://localhost:8000/ws/{userID}

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📄 Templates Management

The Notification Service supports templated messages with dynamic variables for notifications.
Templates are stored in PostgreSQL and can be created, deleted, and used dynamically via API endpoints or can be stored as .tmpl files in the store/templates/ folder.

1️⃣ Create a Template

Endpoint:

POST /template/create

Body:

{
  "name": "template_name",
  "content": "Hello {{.variable_name1}}, welcome to our platform! Your account ID is {{.variable_name2}}."
}

2️⃣ Delete a Template

Endpoint:

DELETE /template/delete/{template_name}

3️⃣ Using a Template in Notification

An example of using a template is: Endpoint:

POST /notify

Body:

{
  "type": "email",
  "to": "[email protected]",
  "template": "template_name",
  "vars": {
    "name": "John Doe",
    "account_id": "ACC12345"
  }
}

Altervatively, if the content is stored in a .tmpl file in the above mentioned directory, the name of the file may be passed in the "template:" field in the request body along with the variables.

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🧪 Testing Endpoints

Check if service is alive:

• GET /health → Returns whether the SMTP server for sending emails is online
• Basic test route: GET /greet → Returns "Hello World!" if the app is online.

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🧰 Tech Stack

• Language: Golang
• Framework: GoFr, Gorilla WebSocket
• Email Delivery: MailHog (for testing) and GMail SMTP (for actual sending)
• SMS Delivery: Kannel Gateway
• Push Notifications: WebSocket
• Containerization: Docker, Docker Compose
• Database: PostgreSQL (for template storage & management)