Catching ECONNREFUSED in node.js with http.request? - node.js

Question

I'm trying to catch ECONNREFUSED errors when using a HTTP client in node.js. I'm making requests like this:
var http = require('http');
var options = { host: 'localhost', port: '3301', path: '/', method: 'GET' };
http.request(options).on('response', function (res) {
// do some stuff
});
I can't figure out how to catch this error:
Error: connect ECONNREFUSED
at errnoException (net.js:614:11)
at Object.afterConnect [as oncomplete] (net.js:605:18)
If I do request.on('error', function () {});, it doesn't catch it. If I do it like this:
var req = request.on(etc)
req.on('error', function blah () {});
Then I get TypeError: Object false has no method 'on'.
Do I really have to do a top-level uncaught error thing to deal with this? At the moment whatever I do my whole process quits out.
Edit: I found some blog posts on how to do it by creating a connection object, calling request on that, and then binding to errors on the connection object, but doesn't that make the entire http.request() shortcut useless?

Answer 1

Any reason you're not using http://nodejs.org/docs/v0.6.5/api/http.html#http.request as your base? Try this:
var req = http.request(options, function(res) {
// Bind 'data', 'end' events here
});
req.on('error', function(error) {
// Error handling here
});
req.end();

Answer 2

Each call to http.request() returns its self.
So try it like this...
http.request(options.function(){}).on('error',function(){}).end();

Answer 3

I've got a solution for this, having tried all the suggestions on this (and many other) pages.
My client needs to detect a turnkey product that runs embedded windows. The client is served from a different machine to the turnkey.
The turnkey can be in 3 states:
turned off
booted into windows, but not running the turnkey app
running the turnkey app
My client sends a 'find the turnkey product' GET message to my nodejs/express service, which then tries to find the turnkey product via http.request. The behavior for each of the 3 use cases are;
timeout
ECONNREFUSED - because the windows embedded phase of the turnkey is
refusing connections.
normal response to request (happy day scenario)
The code below handles all 3 scenarios. The trick to catching the ECONNREFUSED event was learning that its handler binds to the socket event.
var http = require('http');
var express = require('express');
var url = require('url');
function find (req, res) {
var queryObj = url.parse(req.url, true).query;
var options = {
host: queryObj.ip, // client attaches ip address of turnkey to url.
port: 1234,
path: '/some/path',
}; // http get options
var badNews = function (e) {
console.log (e.name + ' error: ', e.message);
res.send({'ok': false, 'msg': e.message});
}; // sends failure messages to log and client
// instantiate http request object and fire it
var msg = http.request(options, function (response) {
var body = '';
response.on ('data', function(d) {
body += d;
}); // accumulate response chunks
response.on ('end', function () {
res.send({'ok': true, 'msg': body});
console.log('sent ok');
}); // done receiving, send reply to client
response.on('error', function (e) {
badNews(e);
}); // uh oh, send bad news to client
});
msg.on('socket', function(socket) {
socket.setTimeout(2000, function () { // set short timeout so discovery fails fast
var e = new Error ('Timeout connecting to ' + queryObj.ip));
e.name = 'Timeout';
badNews(e);
msg.abort(); // kill socket
});
socket.on('error', function (err) { // this catches ECONNREFUSED events
badNews(err);
msg.abort(); // kill socket
});
}); // handle connection events and errors
msg.on('error', function (e) { // happens when we abort
console.log(e);
});
msg.end();
}

Answer 4

For those not using DNS (you can also use request instead of get by simply replacing get with request like so: http.request({ ... })):
http.get({
host: '127.0.0.1',
port: 443,
path: '/books?author=spongebob',
auth: 'user:p#ssword#'
}, resp => {
let data;
resp.on('data', chunk => {
data += chunk;
});
resp.on('end', () => console.log(data));
}).on('error', err => console.log(err));