How to set up long polling on nginx?

F

fLipE2015-05-19 16:24:37

PHP

fLipE, 2015-05-19 16:24:37

I'm trying to organize a primitive messaging through long-polling using nginx.
I took this article as an example: habrahabr.ru/post/252349
Problem: I can’t add a subscriber to /sub/ - the browser swears:
GET localhost/sub/subscriber1 404 (Not Found)
Although, as I understand it, this path must be processed nginx.
nginx config:

http {
     server {
           listen 80 default;
           location ~ /\.ht {
               deny  all;
           }
           location / {
            proxy_pass http://127.0.0.1:8080;
           }
           location /channels-stats {
                # activate channels statistics mode for this location
                push_stream_channels_statistics;

                # query string based channel id
                push_stream_channels_path               $arg_id;
            }
            location /pub {
               # activate publisher (admin) mode for this location
               push_stream_publisher admin;

                # query string based channel id
                push_stream_channels_path               $arg_id;
            }
            location ~ /sub/(.*) {
                # activate subscriber (streaming) mode for this location
                push_stream_subscriber;

                # positional channel path
                push_stream_channels_path                   $1;
                push_stream_longpolling_connection_ttl    30s;
                push_stream_last_received_message_time  $arg_time; 
                push_stream_last_received_message_tag     $arg_tag;
            }
        }
    push_stream_shared_memory_size 32M;
    ...

Channel connection JS code:

var channelId = 'subscriber1'; 
var  last_etag=0; 
var  last_time=null;

function new_message() {
$.ajax({
        url: '/sub/' + channelId,
        type: "GET",
        dataType: 'json',
        beforeSend: function(xhr){xhr.setRequestHeader('Etag', last_etag);xhr.setRequestHeader('Last-Modified', last_time);},
        success: function(data, status, xhr) {
        last_etag =xhr.getResponseHeader('Etag'); 
        last_time =xhr.getResponseHeader('Last-Modified');
        console.log(data);
        setTimeout(new_message, 50);
        }
    })
}
new_message();

When executed in the terminal, you can see that the request to localhost/sub is sent to apache, which, accordingly, returns 404:

$ curl -s -v --no-buffer 'http://localhost/sub/my_channel_1'
* Hostname was NOT found in DNS cache
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 80 (#0)
> GET /sub/my_channel_1 HTTP/1.1
> User-Agent: curl/7.35.0
> Host: localhost
> Accept: */*
> 
< HTTP/1.1 404 Not Found
* Server nginx/1.2.6 is not blacklisted
< Server: nginx/1.2.6
< Date: Tue, 19 May 2015 13:35:12 GMT
< Content-Type: text/html; charset=iso-8859-1
< Content-Length: 288
< Connection: keep-alive
< 
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL /sub/my_channel_1 was not found on this server.</p>
<hr>
<address>Apache/2.4.7 (Ubuntu) Server at localhost Port 80</address>
</body></html>
* Connection #0 to host localhost left intact

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1 answer(s)

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_ _, 2015-05-19
@fLipE

Quote from the manual
First, matches are searched for in prefix locations, and only if nothing is found among them, then regexp.
So location / works for you instead of location ~ /sub/(.*) .
write like this

location / {
            location ~ /sub/(.*) {
                # activate subscriber (streaming) mode for this location
                push_stream_subscriber;

                # positional channel path
                push_stream_channels_path                   $1;
                push_stream_longpolling_connection_ttl    30s;
                push_stream_last_received_message_time  $arg_time; 
                push_stream_last_received_message_tag     $arg_tag;
            }

            proxy_pass http://127.0.0.1:8080;
}