@stoplight/moleculer/src/middlewares/debugging/transit-logger.js

Fast & powerful microservices framework for Node.JS

/*
 * moleculer
 * Copyright (c) 2019 MoleculerJS (https://github.com/moleculerjs/moleculer)
 * MIT Licensed
 */

"use strict";

const _ = require("lodash");
const kleur = require("kleur");
const fs = require("fs");
const path = require("path");
const { makeDirs } = require("../../utils");

module.exports = function TransitLoggerMiddleware(opts) {
	opts = _.defaultsDeep(opts, {
		logger: null,
		logLevel: "info",
		logPacketData: false,

		folder: null,
		extension: ".json",

		colors: {
			receive: "grey",
			send: "grey"
		},

		packetFilter: ["HEARTBEAT"]
	});

	let logger;
	let nodeID;

	let targetFolder;

	function saveToFile(filename, payload) {
		const data = JSON.stringify(
			payload,
			payload instanceof Error ? Object.getOwnPropertyNames(payload) : null,
			4
		);
		fs.writeFile(path.join(targetFolder, filename), data, () => {
			/* Silent error */
		});
	}

	const coloringSend =
		opts.colors && opts.colors.send
			? opts.colors.send.split(".").reduce((a, b) => a[b] || a()[b], kleur)
			: s => s;
	const coloringReceive =
		opts.colors && opts.colors.receive
			? opts.colors.receive.split(".").reduce((a, b) => a[b] || a()[b], kleur)
			: s => s;

	let logFn;

	return {
		name: "TransitLogger",
		created(broker) {
			logger = opts.logger || broker.getLogger("debug");
			nodeID = broker.nodeID;

			if (opts.folder) {
				targetFolder = path.join(opts.folder, nodeID);
				makeDirs(targetFolder);
			}

			logFn = opts.logLevel ? logger[opts.logLevel] : null;
		},

		transitPublish(next) {
			return packet => {
				// Packet filtering
				if (opts.packetFilter.includes(packet.type)) {
					return next(packet);
				}

				const payload = packet.payload;

				// Logging to logger
				if (logFn) {
					logFn(
						coloringSend(
							`=> Send ${packet.type} packet to '${packet.target || "<all nodes>"}'`
						)
					);
					if (opts.logPacketData) {
						logFn("=>", payload);
					}
				}

				if (targetFolder) {
					saveToFile(
						`${Date.now()}-send-${packet.type}-to-${packet.target || "all"}${
							opts.extension
						}`,
						payload
					);
				}

				return next(packet);
			};
		},

		transitMessageHandler(next) {
			return (cmd, packet) => {
				// Packet filtering
				if (opts.packetFilter.includes(cmd)) {
					return next(cmd, packet);
				}

				const payload = packet.payload;

				if (logFn) {
					logFn(coloringReceive(`<= Receive ${cmd} packet from '${payload.sender}'`));
					if (opts.logPacketData) {
						logFn("<=", packet.payload);
					}
				}

				if (targetFolder) {
					saveToFile(
						`${Date.now()}-receive-${cmd}-from-${payload.sender}${opts.extension}`,
						payload
					);
				}

				return next(cmd, packet);
			};
		}
	};
};