veggiemonk/echoServer.js

## echoServer.js
'use strict';
/**
 * HELP! I am not the author of this, I don't remember where I got this file, it was in es5 at the time.
 * If you know who the author is, please get in touch with me to set the record straight.
 * Thank you and thank to the anonymous original author!
 */

const VERSION = '0.1.0';


let http = require( 'http' );
let dns = require( 'dns' );
let port = process.env.PORT || parseInt( process.argv[ 2 ], 10 ) || 3246;
let echoes = [];
let total = 0;
let live = 0;
let up = new Date().toUTCString();
//replay a single echo
let getEcho = function ( id, res ) {
	res.writeHead( 200, {
		'Content-Type': 'application/json'
	} );
	res.end( JSON.stringify( echoes[ id ], null, 2 ) );
};
//get metadata for all echoes
let getEchos = function ( res ) {
	res.writeHead( 200, {
		'Content-Type': 'application/json'
	} );
	let ips = {};
	let methods = {};
	let stats = {
		live: live,
		total: total,
		totalLength: 0,
		methods: methods,
		ips: ips
	};
	echoes.forEach( function ( echo ) {
		let id = echo.domains || echo.ip;
		if ( !ips[ id ] ) ips[ id ] = [];
		ips[ id ].push( echo.meta.num );
		if ( !methods[ echo.method ] ) methods[ echo.method ] = 0;
		methods[ echo.method ]++;
		stats.totalLength += parseInt( echo.headers[ 'content-length' ], 10 ) || 0;
	} );
	//compress id lists
	for ( let id in ips ) {
		let range = null;
		ips[ id ] = ips[ id ].reduce( function ( nums, num, i, arr ) {
			let lastIndex = arr.length - 1;
			let hasNext = i + 1 <= lastIndex;
			let increments = hasNext && arr[ i + 1 ] === num + 1;
			if ( hasNext && increments ) {
				if ( !range ) range = [ num ];
				return nums;
			} else if ( range ) {
				range.push( num );
				nums.push( range );
				range = null;
				return nums;
			}
			nums.push( num );
			return nums;
		}, [] );
	}
	res.end( JSON.stringify( stats ), null, 2 );
};
//special endpoint for xdomain
let getProxy = function ( xdomain, res ) {
	res.writeHead( 200, {
		'Content-Type': 'text/html'
	} );
	res.end( '<!DOCTYPE HTML>\n' + '<script src="' + ( xdomain || '//rawgit.com/jpillora/xdomain/gh-pages/dist/0.6/xdomain.js' ) + '" master="*"></script>' );
};
//create the server!
http.createServer( function ( req, res ) {
	//special actions
	if ( req.url === '/favicon.ico' ) {
		return res.end();
	} else if ( /^\/echo\/(\d+)\/?/.test( req.url ) ) {
		return getEcho( RegExp.$1, res );
	} else if ( /^\/echoes/.test( req.url ) ) {
		return getEchos( res );
	} else if ( /^\/proxy\.html(\?src=(.+))?$/.test( req.url ) ) {
		return getProxy( RegExp.$2, res );
	}
	//do echo
	let num = echoes.length;
	let ip = req.headers[ 'x-forwarded-for' ] || req.connection.remoteAddress;
	let status = 200;
	if ( /\/status\/(\d{3})/.test( req.url ) ) status = parseInt( RegExp.$1, 10 );
	let delay = 0;
	if ( /\/delay\/(\d{1,5})/.test( req.url ) ) delay = parseInt( RegExp.$1, 10 );
	let host = 'http://' + req.headers[ 'host' ];
	let referer = /^(https?:\/\/[^\/]+)/.test( req.headers[ 'referer' ] ) ? RegExp.$1 : '*';
	let headers = {
		'content-type': 'application/json',
		'echo-server-version': VERSION,
		'cache-control': 'no-cache'
	};
	//apply cors when needed
	if ( host !== referer ) {
		headers[ 'access-control-allow-credentials' ] = true;
		headers[ 'access-control-allow-origin' ] = referer;
		if ( req.headers[ 'access-control-request-method' ] ) headers[ 'access-control-allow-methods' ] = req.headers[ 'access-control-request-method' ];
		if ( req.headers[ 'access-control-request-headers' ] ) headers[ 'access-control-allow-headers' ] = req.headers[ 'access-control-request-headers' ];
		headers[ 'access-control-max-age' ] = 0;
	}
	total++;
	live++;
	//wipe heroku headers
	for ( let k in req.headers )
		if ( /^x-/.test( k ) ) delete req.headers[ k ];
	let data = {
		ip: ip,
		domains: null, //unset
		time: Date.now(),
		method: req.method,
		url: req.url,
		body: '',
		headers: req.headers,
		meta: {
			up: up,
			num: num,
			live: live,
			status: status,
			delay: delay
		}
	};
	//echoes fall off the front
	if ( echoes.length >= 100 ) echoes.unshift();
	//push onto the back
	echoes.push( data );
	req.on( 'data', function ( buffer ) {
		data.body += buffer.toString();
	} );
	let send = function () {
		//send after has domains AND request ended
		if ( data.domains === null || !req.ended ) return;

		let buff = new Buffer( JSON.stringify( data, null, 2 ) );
		let length = buff.length;
		headers[ 'content-length' ] = length;
		//write header
		res.writeHead( status, headers );

		function end( buff ) {
			if ( buff ) res.write( buff );
			res.end();
			live--;
		}
		//write all now
		if ( delay === 0 ) return end( buff );
		//with delay, write out 10 chunks over 10 time intervals
		let d = Math.ceil( delay / 10 );
		let l = Math.ceil( length / 10 );
		( function sendChunk() {
			let b = buff.slice( 0, l );
			if ( b.length === 0 ) return end();
			res.write( b );
			buff = buff.slice( l );
			setTimeout( sendChunk, d );
		}() );
	};
	//attempt a reverse lookup on the remote ip
	try {
		dns.reverse( ip, function ( err, domains ) {
			data.domains = domains ? domains.length === 1 ? domains[ 0 ] : domains.length >= 2 ? domains : undefined : undefined;
			send();
		} );
	} catch ( err ) {
		data.domains = undefined;
		send();
	}
	//
	req.on( 'end', function () {
		req.ended = true;
		send();
	} );
} ).listen( port, '0.0.0.0', function () {
	console.log( 'listening on ' + port + '...' ); //eslint-disable-line
} );
	'use strict';
	/**
	* HELP! I am not the author of this, I don't remember where I got this file, it was in es5 at the time.
	* If you know who the author is, please get in touch with me to set the record straight.
	* Thank you and thank to the anonymous original author!
	*/

	const VERSION = '0.1.0';


	let http = require( 'http' );
	let dns = require( 'dns' );
	let port = process.env.PORT \|\| parseInt( process.argv[ 2 ], 10 ) \|\| 3246;
	let echoes = [];
	let total = 0;
	let live = 0;
	let up = new Date().toUTCString();
	//replay a single echo
	let getEcho = function ( id, res ) {
	res.writeHead( 200, {
	'Content-Type': 'application/json'
	} );
	res.end( JSON.stringify( echoes[ id ], null, 2 ) );
	};
	//get metadata for all echoes
	let getEchos = function ( res ) {
	res.writeHead( 200, {
	'Content-Type': 'application/json'
	} );
	let ips = {};
	let methods = {};
	let stats = {
	live: live,
	total: total,
	totalLength: 0,
	methods: methods,
	ips: ips
	};
	echoes.forEach( function ( echo ) {
	let id = echo.domains \|\| echo.ip;
	if ( !ips[ id ] ) ips[ id ] = [];
	ips[ id ].push( echo.meta.num );
	if ( !methods[ echo.method ] ) methods[ echo.method ] = 0;
	methods[ echo.method ]++;
	stats.totalLength += parseInt( echo.headers[ 'content-length' ], 10 ) \|\| 0;
	} );
	//compress id lists
	for ( let id in ips ) {
	let range = null;
	ips[ id ] = ips[ id ].reduce( function ( nums, num, i, arr ) {
	let lastIndex = arr.length - 1;
	let hasNext = i + 1 <= lastIndex;
	let increments = hasNext && arr[ i + 1 ] === num + 1;
	if ( hasNext && increments ) {
	if ( !range ) range = [ num ];
	return nums;
	} else if ( range ) {
	range.push( num );
	nums.push( range );
	range = null;
	return nums;
	}
	nums.push( num );
	return nums;
	}, [] );
	}
	res.end( JSON.stringify( stats ), null, 2 );
	};
	//special endpoint for xdomain
	let getProxy = function ( xdomain, res ) {
	res.writeHead( 200, {
	'Content-Type': 'text/html'
	} );
	res.end( '<!DOCTYPE HTML>\n' + '<script src="' + ( xdomain \|\| '//rawgit.com/jpillora/xdomain/gh-pages/dist/0.6/xdomain.js' ) + '" master="*"></script>' );
	};
	//create the server!
	http.createServer( function ( req, res ) {
	//special actions
	if ( req.url === '/favicon.ico' ) {
	return res.end();
	} else if ( /^\/echo\/(\d+)\/?/.test( req.url ) ) {
	return getEcho( RegExp.$1, res );
	} else if ( /^\/echoes/.test( req.url ) ) {
	return getEchos( res );
	} else if ( /^\/proxy\.html(\?src=(.+))?$/.test( req.url ) ) {
	return getProxy( RegExp.$2, res );
	}
	//do echo
	let num = echoes.length;
	let ip = req.headers[ 'x-forwarded-for' ] \|\| req.connection.remoteAddress;
	let status = 200;
	if ( /\/status\/(\d{3})/.test( req.url ) ) status = parseInt( RegExp.$1, 10 );
	let delay = 0;
	if ( /\/delay\/(\d{1,5})/.test( req.url ) ) delay = parseInt( RegExp.$1, 10 );
	let host = 'http://' + req.headers[ 'host' ];
	let referer = /^(https?:\/\/[^\/]+)/.test( req.headers[ 'referer' ] ) ? RegExp.$1 : '*';
	let headers = {
	'content-type': 'application/json',
	'echo-server-version': VERSION,
	'cache-control': 'no-cache'
	};
	//apply cors when needed
	if ( host !== referer ) {
	headers[ 'access-control-allow-credentials' ] = true;
	headers[ 'access-control-allow-origin' ] = referer;
	if ( req.headers[ 'access-control-request-method' ] ) headers[ 'access-control-allow-methods' ] = req.headers[ 'access-control-request-method' ];
	if ( req.headers[ 'access-control-request-headers' ] ) headers[ 'access-control-allow-headers' ] = req.headers[ 'access-control-request-headers' ];
	headers[ 'access-control-max-age' ] = 0;
	}
	total++;
	live++;
	//wipe heroku headers
	for ( let k in req.headers )
	if ( /^x-/.test( k ) ) delete req.headers[ k ];
	let data = {
	ip: ip,
	domains: null, //unset
	time: Date.now(),
	method: req.method,
	url: req.url,
	body: '',
	headers: req.headers,
	meta: {
	up: up,
	num: num,
	live: live,
	status: status,
	delay: delay
	}
	};
	//echoes fall off the front
	if ( echoes.length >= 100 ) echoes.unshift();
	//push onto the back
	echoes.push( data );
	req.on( 'data', function ( buffer ) {
	data.body += buffer.toString();
	} );
	let send = function () {
	//send after has domains AND request ended
	if ( data.domains === null \|\| !req.ended ) return;

	let buff = new Buffer( JSON.stringify( data, null, 2 ) );
	let length = buff.length;
	headers[ 'content-length' ] = length;
	//write header
	res.writeHead( status, headers );

	function end( buff ) {
	if ( buff ) res.write( buff );
	res.end();
	live--;
	}
	//write all now
	if ( delay === 0 ) return end( buff );
	//with delay, write out 10 chunks over 10 time intervals
	let d = Math.ceil( delay / 10 );
	let l = Math.ceil( length / 10 );
	( function sendChunk() {
	let b = buff.slice( 0, l );
	if ( b.length === 0 ) return end();
	res.write( b );
	buff = buff.slice( l );
	setTimeout( sendChunk, d );
	}() );
	};
	//attempt a reverse lookup on the remote ip
	try {
	dns.reverse( ip, function ( err, domains ) {
	data.domains = domains ? domains.length === 1 ? domains[ 0 ] : domains.length >= 2 ? domains : undefined : undefined;
	send();
	} );
	} catch ( err ) {
	data.domains = undefined;
	send();
	}
	//
	req.on( 'end', function () {
	req.ended = true;
	send();
	} );
	} ).listen( port, '0.0.0.0', function () {
	console.log( 'listening on ' + port + '...' ); //eslint-disable-line
	} );