moleculer/src/transporters/redis.js

Fast & powerful microservices framework for Node.JS

/*
 * moleculer
 * Copyright (c) 2017 Ice Services (https://github.com/ice-services/moleculer)
 * MIT Licensed
 */

"use strict";

const Promise		= require("bluebird");
const Transporter 	= require("./base");

/**
 * Transporter for Redis
 * 
 * @class RedisTransporter
 * @extends {Transporter}
 */
class RedisTransporter extends Transporter {

	/**
	 * Creates an instance of RedisTransporter.
	 * 
	 * @param {any} opts
	 * 
	 * @memberOf RedisTransporter
	 */
	constructor(opts) {
		super(opts);
		
		if (typeof this.opts == "string")
			this.opts = { redis: this.opts };
		
		this.clientPub = null;
		this.clientSub = null;
	}

	/**
	 * Connect to the server
	 * 
	 * @memberOf RedisTransporter
	 */
	connect() {
		return new Promise((resolve, reject) => {
			let Redis;
			try {
				Redis = require("ioredis");
			} catch(err) {
				/* istanbul ignore next */
				this.broker.fatal("The 'ioredis' package is missing! Please install it with 'npm install ioredis --save' command!", err, true);
			}

			const clientSub = new Redis(this.opts.redis);
			this._clientSub = clientSub; // For tests

			clientSub.on("connect", () => {
				this.logger.info("Redis-sub connected!");

				const clientPub = new Redis(this.opts.redis);
				this._clientPub = clientPub; // For tests

				clientPub.on("connect", () => {
					this.clientSub = clientSub;
					this.clientPub = clientPub;

					this.logger.info("Redis-pub connected!");

					this.onConnected().then(resolve);
				});

				/* istanbul ignore next */
				clientPub.on("error", (e) => {
					this.logger.error("Redis-pub error", e);

					if (!this.connected)
						reject(e);
				});
				
				/* istanbul ignore next */
				clientPub.on("close", () => {
					this.connected = true;
					this.logger.warn("Redis-pub disconnected!");
				});					
			});

			clientSub.on("message", (topic, msg) => {
				const cmd = topic.split(".")[1];
				this.messageHandler(cmd, msg);
			});

			/* istanbul ignore next */
			clientSub.on("error", (e) => {
				this.logger.error("Redis-sub error", e);
			});

			/* istanbul ignore next */
			clientSub.on("close", () => {
				this.connected = true;
				this.logger.warn("Redis-sub disconnected!");
			});		
		
		});
	}

	/**
	 * Disconnect from the server
	 * 
	 * @memberOf RedisTransporter
	 */
	disconnect() {
		if (this.clientSub) {
			this.clientSub.disconnect();
			this.clientSub = null;
		}

		if (this.clientPub) {
			this.clientPub.disconnect();
			this.clientPub = null;
		}
	}

	/**
	 * Subscribe to a command
	 * 
	 * @param {String} cmd 
	 * @param {String} nodeID 
	 * 
	 * @memberOf RedisTransporter
	 */
	subscribe(cmd, nodeID) {
		this.clientSub.subscribe(this.getTopicName(cmd, nodeID));
	}

	/**
	 * Publish a packet
	 * 
	 * @param {Packet} packet
	 * 
	 * @memberOf RedisTransporter
	 */
	publish(packet) {
		const data = packet.serialize();
		this.clientPub.publish(this.getTopicName(packet.type, packet.target), data);
	}

}

module.exports = RedisTransporter;