Node-http-proxy: Must provide a proper URL as target : options are empty for some reason

[mbret]

I'm using a simple proxy for web and socket and for some reason some of my request throw errors.

instead of having an object with { target: .., forward: ... } I got an empty withouth these two key. However I do have the "secure" key that I set while creating proxy object and I do have "prependPath".

Ex:
For most of my sockets request I have usually:

{ target:
   Url {
     protocol: 'https:',
     slashes: true,
     auth: null,
     host: 'localhost:3001',
     port: '3001',
     hostname: 'localhost',
     hash: null,
     search: null,
     query: null,
     pathname: '/',
     path: '/',
     href: 'https://localhost:3001/' },
  forward:
   Url {
     protocol: null,
     slashes: null,
     auth: null,
     host: null,
     port: null,
     hostname: null,
     hash: null,
     search: '?EIO=3&transport=polling&t=1483089414416-48&sid=CyuT-vFAV_iKoec5AAAC',
     query: 'EIO=3&transport=polling&t=1483089414416-48&sid=CyuT-vFAV_iKoec5AAAC',
     pathname: '/socket.io/',
     path: '/socket.io/?EIO=3&transport=polling&t=1483089414416-48&sid=CyuT-vFAV_iKoec5AAAC',
     href: '/socket.io/?EIO=3&transport=polling&t=1483089414416-48&sid=CyuT-vFAV_iKoec5AAAC' },
  secure: false,
  prependPath: true }

For some other I only got
{ secure: false, prependPath: true }

which is why the module throw error because of this check

if (!options.target && !options.forward) {
   return this.emit('error', new Error('Must provide a proper URL as target'));
}

Here is what I do on my server side

app.locals.proxy = httpProxy.createProxyServer({
      secure: false
});

app.all("/remote-api/*", function(req, res) {
    req.app.locals.proxy.web(req, res, { target: req.app.locals.system.config.sharedApiUrl, forward: req.url });
});

server.on('upgrade', function (req, socket, head) {
    app.locals.proxy.ws(req, socket, head);
});

My stack is pretty simple and as I said, all my web request are ok, pretty much all sockets too. Only some of them fails.

[mbret]

After some digging, only the web socket request from wss:// are in cause. What is strange is that my web page is working, connected and receiving socket connection. Also when I use a dedicated proxy server (instead of my actual server) it works without any problem. So I think I'm missing some configuration with the socket proxying part ?

[jcrugzz]

@mbret its because for your web proxy requests, you specify your target, you do not do the same for the ws proxy requests on the upgrade event. Add a 4th argument to the function that is an object that specifies { target: req.app.locals.system.config.sharedApiUrl })

Your example should look like:

app.locals.proxy = httpProxy.createProxyServer({
      secure: false
});

app.all("/remote-api/*", function(req, res) {
    req.app.locals.proxy.web(req, res, { target: req.app.locals.system.config.sharedApiUrl });
});

server.on('upgrade', function (req, socket, head) {
    app.locals.proxy.ws(req, socket, head,  { target: req.app.locals.system.config.sharedApiUrl });
});

[mbret]

Of course I did not -_-

Thanks a lot @jcrugzz. To be honest I'm a bit stupid because some of my socket request pass through http and so inside the req.app.locals.proxy.web. So I naively thought that my app.locals.proxy.ws was okay like this. Don't know if you get what I mean but whatever, thank you :)

[jcrugzz]

yea if it was using the socket.io longpolling those would have worked, but if it upgraded, then the issues began. No problem and good luck

[guyonroche]

@jcrugzz A great thank you for your efforts on this module!
Just a comment - is it worth changing the README.md file to reflect the above advice?
I had exactly the same code as @mbret as I'd copied it from the example in the readme, encountered the same error and after a quick googling, ended up here...