rework tunnel logic

Refactoring to make things a bit saner and easier to debug.
This commit is contained in:
Roman Shtylman
2013-12-05 11:26:19 -05:00
parent 1c2757e604
commit 3354c4c6e3
2 changed files with 153 additions and 128 deletions

279
client.js
View File

@@ -2,28 +2,119 @@ var net = require('net');
var url = require('url');
var EventEmitter = require('events').EventEmitter;
var after = require('after');
var request = require('request');
var debug = require('debug')('localtunnel:client');
// request upstream url and connection info
var request_url = function(params, cb) {
request(params, function(err, res, body) {
if (err) {
return cb(err);
}
// manages groups of tunnels
var TunnelCluster = function(opt) {
if (!(this instanceof TunnelCluster)) {
return new TunnelCluster(opt);
}
cb(null, body);
});
var self = this;
self._opt = opt;
EventEmitter.call(self);
};
var connect = function(opt) {
TunnelCluster.prototype.__proto__ = EventEmitter.prototype;
// establish a new tunnel
TunnelCluster.prototype.open = function() {
var self = this;
var opt = self._opt || {};
var remote_host = opt.remote_host;
var remote_port = opt.remote_port;
var local_host = opt.local_host;
var local_port = opt.local_port;
debug('establishing tunnel %s:%s <> %s:%s', local_host, local_port, remote_host, remote_port);
// connection to localtunnel server
var remote = net.connect({
host: remote_host,
port: remote_port
});
remote.once('error', function(err) {
// emit connection refused errors immediately, because they
// indicate that the tunnel can't be established.
if (err.code === 'ECONNREFUSED') {
self.emit('error', new Error('connection refused: ' + remote_host + ':' + remote_port + ' (check your firewall settings)'));
}
else {
self.emit('error', err);
}
setTimeout(function() {
self.emit('dead');
}, 1000);
});
function conn_local() {
debug('connecting locally to %s:%d', local_host, local_port);
remote.pause();
// connection to local http server
var local = net.connect({
host: local_host,
port: local_port
});
function remote_close() {
self.emit('dead');
local.unpipe();
local.end();
};
remote.once('close', remote_close);
local.on('error', function(err) {
local.end();
remote.removeListener('close', remote_close);
if (err.code !== 'ECONNREFUSED') {
return local.emit('error', err);
}
// retrying connection to local server
setTimeout(conn_local, 1000);
});
local.once('connect', function() {
debug('connected locally');
remote.resume();
remote.pipe(local).pipe(remote);
// when local closes, also get a new remote
local.once('close', function(had_error) {
remote.unpipe();
local.unpipe();
remote.end();
debug('local connection closed [%s]', had_error);
});
});
}
// tunnel is considered open when remote connects
remote.once('connect', function() {
self.emit('open');
});
remote.once('connect', conn_local);
};
var init = function(opt, cb) {
var ev = new EventEmitter();
// local host
var local_host = opt.local_host;
// local port
var local_port = opt.port;
var params = {
path: '/',
json: true
};
var base_uri = opt.host + '/';
@@ -33,134 +124,68 @@ var connect = function(opt) {
// no subdomain at first, maybe use requested domain
var assigned_domain = opt.subdomain;
// connect to upstream given connection parameters
var tunnel = function (remote_host, remote_port, dead) {
var remote_opt = {
host: remote_host,
port: remote_port
};
var local_opt = {
host: local_host,
port: local_port
};
var remote_attempts = 0;
(function conn(conn_had_error) {
if (conn_had_error) {
return;
}
// we need a new tunnel
if (++remote_attempts >= 3) {
return dead();
}
// connection to localtunnel server
var remote = net.connect(remote_opt);
remote.once('error', function(err) {
// emit connection refused errors immediately, because they
// indicate that the tunnel can't be established.
if (err.code === 'ECONNREFUSED') {
ev.emit('error', new Error('connection refused: ' + remote_host + ':' + remote_port + ' (check your firewall settings)'));
}
else {
remote.emit('error', err);
}
// retrying connection to local server
setTimeout(conn, 1000);
});
function recon_local() {
remote.pause();
remote_attempts = 0;
// connection to local http server
var local = net.connect(local_opt);
local.once('error', function(err) {
if (err.code !== 'ECONNREFUSED') {
local.emit('error', err);
}
// retrying connection to local server
setTimeout(recon_local, 1000);
});
local.once('connect', function() {
remote.resume();
remote.pipe(local).pipe(remote, {end: false});
});
local.once('close', function(had_error) {
if (had_error) {
return;
}
recon_local();
});
}
remote.once('close', conn);
remote.once('connect', recon_local);
})();
};
var params = {
path: '/',
json: true
};
// where to quest
params.uri = base_uri + ((assigned_domain) ? assigned_domain : '?new');
function init_tunnel() {
// get an id from lt server and setup forwarding tcp connections
request_url(params, function(err, body) {
(function get_url() {
request(params, function(err, res, body) {
if (err) {
ev.emit('error', new Error('tunnel server not available: ' + err.message + ', retry 1s'));
ev.emit('error', new Error('tunnel server offline: ' + err.message + ', retry 1s'));
// retry interval for id request
return setTimeout(function() {
init_tunnel();
}, 1000);
return setTimeout(get_url, 1000);
}
// our assigned hostname and tcp port
var port = body.port;
var host = upstream.hostname;
// store the id so we can try to get the same one
assigned_domain = body.id;
var max_conn = body.max_conn_count || 1;
// after all our tunnels die, we ask for new ones
// this might happen if the upstream server dies
var dead = after(max_conn, function() {
init_tunnel();
cb(null, {
remote_host: upstream.hostname,
remote_port: body.port,
name: body.id,
url: body.url,
max_conn: max_conn
});
for (var count = 0 ; count < max_conn ; ++count) {
tunnel(host, port, dead);
}
ev.emit('url', body.url);
});
}
init_tunnel();
})();
return ev;
};
module.exports.connect = connect;
module.exports.connect = function(opt) {
var client = init(opt, function(err, info) {
// for backwards compatibility
// old localtunnel modules had server and client code in same module
// so to keep .client working we expose it here
module.exports.client = module.exports;
info.local_host = opt.local_host;
info.local_port = opt.port;
var tunnels = TunnelCluster(info);
// only emit the url the first time
tunnels.once('open', function() {
client.emit('url', info.url);
});
var tunnel_count = 0;
// track open count
tunnels.on('open', function(tunnel) {
tunnel_count++;
debug('tunnel open [total: %d]', tunnel_count);
});
// when a tunnel dies, open a new one
tunnels.on('dead', function() {
tunnel_count--;
debug('tunnel dead [total: %d]', tunnel_count);
tunnels.open();
});
// establish as many tunnels as allowed
for (var count = 0 ; count < info.max_conn ; ++count) {
tunnels.open();
}
});
return client;
};

View File

@@ -10,7 +10,7 @@
"dependencies": {
"request": "2.11.4",
"optimist": "0.3.4",
"after": "0.8.1"
"debug": "0.7.4"
},
"devDependencies": {},
"bin": {