amqpsnoop/lib/amqpsnoop.js

snoop AMQP messages

#!/usr/bin/env node

/*
 * amqpsnoop.js: snoop AMQP traffic
 *
 * Copyright 2011 Joyent. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

var mod_amqp = require('amqp');
var mod_getopt = require('posix-getopt');
var mod_util = require('util');
var mod_vm = require('vm');

var aq_usage_message = [
    'usage: amqpsnoop [-h host] [-r routekey] [-f filter...] [-x exchange]',
    '',
    'Snoops AMQP messages sent to routekey <routekey> using broker <host>.',
    'All messages must be JSON-encoded objects.  The following options may ',
    'be specified:',
    '',
    '    -h host        hostname of AMQP broker to use (default: localhost)',
    '',
    '    -r routekey    routekey to bind to (default: "#")',
    '',
    '    -f filter      filter expression to invoke on each message',
    '                   Multiple filters may be specified.  Each one is a ',
    '                   chunk of JavaScript code to be executed with each ',
    '                   message bound to variable "msg".  The message is ',
    '                   only printed if all filters return true.',
    '',
    '    -o format      output messages with the given format',
    '                   Valid values are "inspect" (uses util.inspect, the)',
    '                   default), "json" and "json0" (JSON with no ',
    '                   indentation).',
    '',
    '    -x exchange    exchange name (default: "amq.topic")',
    '',
    'Example: using broker 10.99.99.5, show all AMQP messages sent to any ',
    'routing key starting with "ca." and whose "ca_subtype" member is not ',
    '"ping":',
    '',
    '    amqpsnoop -h 10.99.99.5 -r "ca.#" -f \'msg.ca_subtype != "ping"\''
].join('\n');

var aq_broker = { host: 'localhost' };	/* AMQP configuration */
var aq_routekey = '#';			/* routing key to listen to */
var aq_exchange = 'amq.topic';		/* exchange name */
var aq_filters = [];

var aq_queuename;			/* local queue name */
var aq_amqp;				/* amqp connection */
var aq_queue;				/* local queue */

var aq_outputters = {
	'inspect': function (msg) {
		console.log(mod_util.inspect(msg, false, null));
	},
	'json': function (msg) {
		console.log(JSON.stringify(msg, null, 2));
	},
	'json0': function (msg) {
		console.log(JSON.stringify(msg, null, 0));
	}
};
var aq_outputter = aq_outputters['inspect'];	/* outputter function */


function main()
{
	aqParseOptions();

	aq_queuename = 'amqpsnoop.' + Math.random() * 10000000;
	aq_amqp = mod_amqp.createConnection(aq_broker);
	aq_amqp.on('ready', function () {
		aq_queue = aq_amqp.queue(aq_queuename,
		    { exclusive: true }, function () {
			aq_queue.bind(aq_exchange, aq_routekey);
			aq_queue.subscribe(aqReceiveMessage);
		    });
	});
}

function aqUsage()
{
	console.error(aq_usage_message);
	process.exit(1);
}

function aqParseOptions()
{
	var parser, cc;

	parser = new mod_getopt.BasicParser('f:r:h:o:x:', process.argv);
	while ((cc = parser.getopt()) !== undefined) {
		if (cc['error'])
			aqUsage();

		switch (cc['option']) {
		case 'h':
			aq_broker['host'] = cc['optarg'];
			break;

		case 'r':
			aq_routekey = cc['optarg'];
			break;

		case 'f':
			aq_filters.push(
			    mod_vm.createScript(cc['optarg']));
			break;

		case 'o':
			aq_outputter = aq_outputters[cc['optarg']];
			if (aq_outputter === undefined) {
				console.error('unknown output format: %s',
					      cc['optarg']);
				aqUsage();
			}
			break;

		case 'x':
			aq_exchange = cc['optarg'];
			break;
		}
	}
}

function aqReceiveMessage(msg)
{
	var ii;

	for (ii = 0; ii < aq_filters.length; ii++) {
		if (!(aqFilterApply(aq_filters[ii], msg)))
			return;
	}

	aq_outputter(msg);
}

function aqFilterApply(script, msg)
{
	try {
		return (script.runInNewContext({ msg: msg }));
	} catch (ex) {
		console.error('ERROR applying filter: %s', ex.message);
		return (false);
	}
}

main();