Nginx how to proxy_pass to a proxy

nginx

I have a nginx server running. I want to issue some request to a corporate proxy and return the result to the client.

Let us say the client issues a request to http://ip:port/redirect/google.com, the server should issue the request to https://username:password@ip_proxy with the requested url as parameter.

I have found questions that are close to my problem:

http://serverfault.com/questions/732063/nginx-proxy-pass-reverse-proxying-behind-corporate-firewall
and
http://stackoverflow.com/questions/11865119/how-to-configure-nginx-behind-a-corporate-proxy

assume 205.100.100.100:80 is the proxy URI and
XXVzYTQzMjXXXDpCb25qXXyMQ== the credential for the proxy

one says we should rewrite the url and then pass it to proxy_pass directive

location ^~ /redirect/ {
        rewrite ^/redirect/(.*) https://google.com;
        proxy_pass_header on;
        proxy_set_header Proxy-Authorization "XXVzYTQzMjXXXDpCb25qXXyMQ==";
        proxy_pass https://205.100.100.100:80;
}

I think it does not work as intended cause it is showing as a redirection (http code 301)

Another one says that we should use the Host header and specify original url with it:

location ^~ /redirect/ {
        proxy_pass_header on;
        proxy_set_header Host "https://google.com";
        proxy_set_header Proxy-Authorization "XXVzYTQzMXXXpCb25XXyMQ==";
        proxy_pass https://205.100.100.100:80;
}

Doesn't work. They also say that a proxy read the url specified as an url parameter something like: http://proxy:port/url_requested so:

location /redirect { 
    rewrite ^/redirect/(.*)"http://205.100.100.100:80/https://google.com" break; 
    proxy_pass_header on;
    proxy_set_header Proxy-Authorization "XXVzYTQzMXXXpCb25XXyMQ==";
    proxy_pass http://corporate-proxy.mycorp.com:8080; 
}

Should work ?

As you can see I do not know how to specify the username, password to the proxy. I tried a Proxy-Authorization header with "XXVzYTQzMjXXXDpCb25qXXyMQ==" with no result.

I tried the http_upstream module too, no result. I cannot use proxy_pass http://user:pwd@205.100.100.100:80 because nginx use ":" for parsing the port, it gives me error specifying port.

How should I proceed ?

Maybe it comes from the entire configuration or they way I use the proxy? Don't know.

Best Answer

This isn't possible, nginx isn't able to talk to forward proxy.

See also this thread in the official mailing list: http://mailman.nginx.org/pipermail/nginx-devel/2013-March/003534.html

Related Solutions

Node.js + Nginx – What now

Nginx works as a front end server, which in this case proxies the requests to a node.js server. Therefore you need to setup an nginx config file for node.

This is what I have done in my Ubuntu box:

Create the file yourdomain.com at /etc/nginx/sites-available/:

vim /etc/nginx/sites-available/yourdomain.com

In it you should have something like:

# the IP(s) on which your node server is running. I chose port 3000.
upstream app_yourdomain {
    server 127.0.0.1:3000;
    keepalive 8;
}

# the nginx server instance
server {
    listen 80;
    listen [::]:80;
    server_name yourdomain.com www.yourdomain.com;
    access_log /var/log/nginx/yourdomain.com.log;

    # pass the request to the node.js server with the correct headers
    # and much more can be added, see nginx config options
    location / {
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_set_header X-NginX-Proxy true;

      proxy_pass http://app_yourdomain/;
      proxy_redirect off;
    }
 }

If you want nginx (>= 1.3.13) to handle websocket requests as well, add the following lines in the location / section:

proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";

Once you have this setup you must enable the site defined in the config file above:

cd /etc/nginx/sites-enabled/ 
ln -s /etc/nginx/sites-available/yourdomain.com yourdomain.com

Create your node server app at /var/www/yourdomain/app.js and run it at localhost:3000

var http = require('http');

http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Hello World\n');
}).listen(3000, "127.0.0.1");
console.log('Server running at http://127.0.0.1:3000/');

Test for syntax mistakes:

nginx -t

Restart nginx:

sudo /etc/init.d/nginx restart

Lastly start the node server:

cd /var/www/yourdomain/ && node app.js

Now you should see "Hello World" at yourdomain.com

One last note with regards to starting the node server: you should use some kind of monitoring system for the node daemon. There is an awesome tutorial on node with upstart and monit.

Nginx – How to configure Nginx behind a corporate proxy

Not sure how @tacos response can work - possibly something I'm missing but the only way I could sort of get this to work was by rewriting the url and passing on to the corporate proxy. This is shown below:

http {
  server {
    listen 80;
    location / {
          rewrite ^(.*)$ "http://www.externalsite.com$1" break;
          proxy_pass http://corporate-proxy.mycorp.com:8080;
    }
  }
}

This works, but does rewrite the url, not sure if this is important to the original use-case..

Best Answer

Related Solutions

Node.js + Nginx – What now

Nginx – How to configure Nginx behind a corporate proxy

Related Topic