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NATS Messaging

The CREDEBL platform utilizes NATS for message-driven data exchange between its microservices. NATS serves as a lightweight and high-performance “message-oriented middleware,” allowing services to communicate seamlessly in real-time.

Why NATS?

NATS enables CREDEBL platform services to exchange data effectively by breaking down communication into discrete messages. With NATS, application developers can:

  • Build distributed and scalable client-server applications effortlessly.
  • Store and distribute data in real time, making it adaptable across various environments, languages, cloud providers, and on-premises systems.

Setting Up a NATS Server

Follow the steps below to set up a NATS server for the CREDEBL platform using a configuration file and Docker.

Create the NATS Configuration File (nats-server.conf)

The configuration file defines how the NATS server operates, including port assignments and WebSocket support.

port: 4222
max_payload: 4194304  # 4 MB in bytes
websocket {
  port: 443
  no_tls: true
}
  • port: The main port for NATS communication is set to 4222.
  • max_payload: Sets the maximum message payload size to 4 MB.
  • websocket: Enables WebSocket support on port 443 without TLS (for unsecured communication).

Create the docker-compose.yml File

The docker-compose.yml file will define the NATS service, map the necessary ports, and bind the configuration file.

version: '3'
services:
  nats:
    container_name: nats
    image: nats
    command: ["-c", "/nats-server.conf"]
    ports:
      - '4222:4222'
      - '6222:6222'
      - '8222:8222'
    volumes:
      - ./nats-server.conf:/nats-server.conf:ro
  • container_name: Sets the name of the container to nats.
  • image: Uses the official NATS Docker image.
  • command: Passes the NATS configuration file to the container at startup.
  • ports: Exposes three key ports:
    • 4222: Main NATS client communication port.
    • 6222: Routing port for NATS clusters.
    • 8222: HTTP monitoring port for server statistics and health checks.
  • volumes: Mounts the nats-server.conf configuration file into the container as read-only (ro).

Start the NATS Server

To start the NATS server, run the following command from the directory containing the docker-compose.yml file:

docker compose up

This command will bring up the NATS container, configured to handle messaging for the CREDEBL platform’s microservices.