AnyEvent:WebSocket produces 'No such device or address' error

meep has asked for the wisdom of the Perl Monks concerning the following question:

First time poster. Learning Perl and have made good progress but I'm stumped by a problem I've encountered when attempting to implement WebSockets....

I have a WebSocket server application built in Node-Red sitting behind an Apache reverse-proxy configuration. (The server is very simple, responding only to 'Ping' commands with an 'OK' response.)

Using the 'Simple Websocket Client' extension for Google Chrome, I can successfully open the server URL, send the 'Ping' request and receive the 'OK' response, so I know that the server setup works.

However, attempting to implement the same in PERL via AnyEvent:Socket, I consistently receive a 'No such device or address' error.p>

The relevant section of my PERL code looks like this;

sub sockInit{

use AnyEvent::WebSocket::Client 0.12;
use URI

my $client = AnyEvent::WebSocket::Client->new( );

 
    my $uri = URI->new('ws://mydomain.com/ws/test');

    $client->connect($uri)->cb(sub {
 
      our $connection = eval { shift->recv };
         if($@) {
          # handle error...
          myDebug($@);
          return;
     }
   
    # send a message through the websocket...
    # $connection->send('ping');
   
   });

  }
[download]

Ultimately, this fails in this section of AnyEvent/WebSocket/Client.pm (around line 90);

#AnyEvent::Socket::tcp_connect $uri->host, $uri->port, sub {
    AnyEvent::Socket::tcp_connect $uri->as_string, 80, sub {
    my $fh = shift;
    unless($fh)
    {
      $done->croak("unable to connect to ".$uri->as_string." $!");
      return;
    }
[download]

(I've made some small edits there to get around issues with $uri->host and $uri->port not existing for URI::_generic which is what ws protocol comes through as. I've also extened the croak message to include the uri)

Here's what it typically generates;

 unable to connect to ws://mydomain.com/ws/test No such device or addr
+ess at /usr/share/squeezeboxserver/Plugins/Alexa/HabProxy.pm line 201
+.
[download]

(This code runs inside a plugin I'm writing for the Logitech SqueezeServer platform)

The relevant part of my Apache hosts config includes these libes in <VirtualHost *.80>

ProxyPass /ws ws://127.0.0.1:1880/ws
ProxyPassReverse  /ws ws://127.0.0.1:1880/ws
[download]

As noted, I know this to be working. Ultimately, I need this to work with user authentication in Apache against a DB and with WSS: but I've simplified extensively here to see if I can track down why my Perl implementation might be failing but it works fine in other clients.

I've learned a lot from this site so far, hopefully someone can help me out with my first problem for which my Google Fu cannot product an answer.

Comment on AnyEvent:WebSocket produces 'No such device or address' error Select or Download Code

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Re: AnyEvent:WebSocket produces 'No such device or address' error by Corion (Patriarch) on Mar 27, 2017 at 15:02 UTC
`AnyEvent::Socket::tcp_connect` likely only wants a hostname or an IP address, not an URI. Maybe you can try the following: `AnyEvent::Socket::tcp_connect 'mydomain.com', 80, sub { my $fh = shift; unless($fh) { $done->croak("unable to connect to ".$uri->as_string." $!"); return; }` [download] This is somewhat the first step, because AnyEvent::Socket doesn't speak whatever protocol websockets layer on top of TCP.	[reply] [d/l] [select]
Re^2: AnyEvent:WebSocket produces 'No such device or address' error by meep (Initiate) on Mar 27, 2017 at 16:51 UTC
Thanks for the response. On foot of your suggestion, I've tried multiple hardcoded variants of the hostname and raw IP address there instead of the passed-in URI but to no avail.	[reply]
Re^3: AnyEvent:WebSocket produces 'No such device or address' error by Corion (Patriarch) on Mar 27, 2017 at 17:01 UTC
Maybe you can reduce your code to a short, self-contained example that we can use to reproduce your problem. I'm not sure where in the layers upon layers of protocol modules the problem lies, so something, maybe using AnyEvent::WebSocket that tries to access a public accessible websocket machine can help us see better what happens.	[reply]
Re: AnyEvent:WebSocket produces 'No such device or address' error by Anonymous Monk on Mar 27, 2017 at 22:38 UTC
Use Mojolicious instead. Set up a real API that returns JSON. `$ perl -Mojo -E 'a("/hello" => {json => {hello => 'world'}})->start' d +aemon` [download] Boom! `xD`	[reply] [d/l]