domotz-remote-pawn/src/http/socketListener.js

Domotz Agent

/** This file is part of Domotz Agent.
 * Copyright (C) 2016  Domotz Ltd
 *
 * Domotz Agent is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Domotz Agent is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Domotz Agent.  If not, see <http://www.gnu.org/licenses/>.
 **/
/**
 * Created by Massimiliano Cuzzoli <mcuzzoli@domotz.com> on 26/08/15.
 *
 */
const MODULE_NAME = 'SOCKET LISTENER';

var factory = function (http, fs, requestHandler) {
    var httpSocketFile = process.env.DOMOTZ_HTTP_ON_UNIX_SOCKET_FILE;
    var server;

    server = http.createServer(function (request, response) {
        // Route on the user agent basis
        if (request.headers && request.headers['user-agent'].indexOf('domotz') === 0) {
            requestHandler.handleRequest(request, response);
            return;
        }
        console.warn('%s - Received invalid user agent: %s', MODULE_NAME, request.headers['user-agent']);
        response.writeHead(400);
        response.end();
    });

    server.on('error', function (err) {
        if (err.code === 'EADDRINUSE') {
            console.debug('%s - Removed existing unix socket: %s', MODULE_NAME, httpSocketFile);
            fs.unlink(httpSocketFile, function (exception) {
                if (exception) {
                    console.warn('%s - Error on unix socket unlink', MODULE_NAME);
                    throw exception;
                }
                console.debug('%s - Retry to listen on: %s', MODULE_NAME, httpSocketFile);
                server.listen(httpSocketFile);
            });
        }
    });

    return {
        socketName: httpSocketFile,
        listen: function listen() {
            console.info('%s - Created socket server for: %s. Start listening on: %s', MODULE_NAME, httpSocketFile, this.socketName);
            return server.listen(this.socketName);
        },
    };
};

module.exports.socketListener = factory;