[PLUG] Browsers, Numeric IPs, and apache Virtual Hosts

[Martin A. Brown]

Greetz Keith,

 : Apache uses virtual hosts to support many different URLs on one 
 : machine on one IP address.  When you connect to apache with your 
 : browser, the browser provides enough information to Apache to 
 : give you the URL you want.
 : 
 : Question:  If the URL is not in the DNS system, and all you have 
 : is the IP address (say, 1.2.3.4) and the name of the virtual 
 : (say, foobar.example.org ), how do you use firefox (or other 
 : browser)

Many people would not agree that 'curl' is an acceptable other 
browser.  With that disclaimer, I will point out that, you can use 
the --header option to my curl (7.20.1) which will set the 'Host' 
header appropriately:

  curl \
    --trace-ascii diagnosis.txt \
    --header 'Host: linux-ip.net' \ 
    -- http://64.22.109.68/

This does several things:

  1. Connects via HTTP to 64.22.109.68
  2. Adds the HTTP header 'Host: linux-ip.net'
  3. Dumps the ASCII representation of the conversation to a file
     called diagnosis.txt.

It can be quite handy when you are dealing with HTTP services that 
require a bit of diagnostics.  I am not Swiss, however, my Swiss 
army CLI network knife is 'socat' where the HTTP CLI equivalent is 
curl.

 : to tell apache at 1.2.3.4 to serve the foobar.example.org 
 : content, or any of the other specific URLs served by virtual 
 : hosts on that machine?
 : 
 : The best way is to provide good DNS, of course, but that isn't 
 : available if all you control is a user account and a browser.

And also, I agree with Paul Heinlein.  Using /etc/hosts is one way 
to work around this sort of impoverished infrastructural 
environment, should you find yourself so constrained.

-Martin

-- 
Martin A. Brown
http://linux-ip.net/