Web-server – how do i set up a minimal webserver, that serves only one page on all requests

web-server

A minimal webserver on port 80 would be

python -m SimpleHTTPServer 80

but I would like to show only one page all the time called maintenance.html, no matter what page was requested.

The url in the browser should still stay the url, that the visitor requested, but no error page.

Best Answer

Giving this answer for the entertainment value mostly, but you could use any super-server (xinetd might do the job, too) and make it run a simple script for every request on port 80. The script would wait for a blank line on standard input and then print a prepared static response. Not sure how much more lightweight you can get.

For example, if using DJB's tcpserver (I find it easy to use for such trivial tasks) you can do:

$ tcpserver 127.0.0.1 1080 sh -c 'awk "/^\r*$/ { exit }"; cat answer'

And in the answer file you can have:

HTTP/1.0 200
Date: Fri, 02 Nov 2012 16:05:54 GMT
Content-Length: 15
Content-Type: text/html; charset=utf-8

This is a test

You can get as creative as you want.

And here is how I test it:

$ wget -q -O - http://localhost:1080/
This is a test

UPDATE: For anyone seriously considering this, for a realistic use of tcpserver you are better off starting it like this:

tcpserver -H -R -l $HOSTNAME -u $(id -u nobody) -g $(id -g nobody) 0.0.0.0 80 sh -c 'awk "/^\r*$/ { exit }"; cat answer'

By default tcpserver looks up information about the incoming connection and -H (do not look up the remote name in DNS) and -R (do not look up remote info with ident) will speed up responding to incoming connections. -u and -g will drop the privileges after receiving the connection on port 80, and you will have to start it as root to be able to listen on port 80.

And of course, make sure nothing else is listening on port 80.