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Kimihito
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Jun 02, 2014

Linerate : HTTP response modification

Hello,

I am trying to catch cliResp to replace its 'Server' header with proxyhost. And bind it to servResp to send it to a client. My script below does not work. I get fpm.on listener is triggered. But when it receives response, I do not see fp.on is kicked in, so no header modification is done. What is wrong with it ?

"use strict";
var fpm = require('lrs/forwardProxyModule');
var os = require('os');
var proxyhost = os.hostname();

fpm.on('exist', 'myForwardProxy', function (fp) {
    console.log('fpm.on');
    fp.on('response', function onResp(servResp, cliResp, next) {
            cliResp.bindHeaders(servResp);
            cliResp.setHeader("Server", proxyhost);
            cliResp.pipe(servResp);
            console.log('response modified');
            next();
    });
});

Thanks, Kimihito.

1 Reply

  • I have got it working.

    "use strict";
    var fpm = require('lrs/forwardProxyModule');
    var os = require('os');
    var proxyhost = os.hostname();
    var processRequest = function(servReq, servResp, next){
        servReq.on('response', function processResponse(cliResp){
                cliResp.bindHeaders(servResp);
                servResp.setHeader("Server", proxyhost);
                cliResp.pipe(servResp);
                console.log('response modified');
        });
        next();
    }
    var createCallback = function(fp) {
        fp.on('request', processRequest);
    };
    fpm.on('exist', 'myForwardProxy', createCallback);
    

    Curl from client. 'Server' is modified from 'Apache/2.2.22 (Debian)' to 'myLinerate'. It is placed in the end of response header. It actually looks removing and adding, instead of 'modifying'.

    root@debian1:~ curl http://172.16.0.1 -v
    * About to connect() to 172.16.0.1 port 80 (0)
    *   Trying 172.16.0.1...
    * connected
    * Connected to 172.16.0.1 (172.16.0.1) port 80 (0)
    > GET / HTTP/1.1
    > User-Agent: curl/7.26.0
    > Host: 172.16.0.1
    > Accept: */*
    > 
    * additional stuff not fine transfer.c:1037: 0 0
    * HTTP 1.1 or later with persistent connection, pipelining supported
    < HTTP/1.1 200 OK
    < Date: Mon, 02 Jun 2014 06:48:03 GMT
    < Last-Modified: Tue, 27 May 2014 05:41:18 GMT
    < ETag: "21a0a-c8-4fa5b251ef22b"
    < Accept-Ranges: bytes
    < Content-Length: 200
    < Vary: Accept-Encoding
    < Content-Type: text/html
    < X-Pad: avoid browser bug
    < Server: myLinerate
    < 
    It works! This is debian server 
    This is the default web page for this server.
    The web server software is running but no content has been added, yet.
    
    * Connection 0 to host 172.16.0.1 left intact
    * Closing connection 0
    root@debian1:~ 
    

    Without the script, it was...

    < HTTP/1.1 200 OK
    < Date: Mon, 02 Jun 2014 06:43:48 GMT
    < Server: Apache/2.2.22 (Debian)
    < Last-Modified: Tue, 27 May 2014 05:41:18 GMT
    < ETag: "21a0a-c8-4fa5b251ef22b"
    < Accept-Ranges: bytes
    < Content-Length: 200
    < Vary: Accept-Encoding
    < Content-Type: text/html
    < X-Pad: avoid browser bug
    <