APPROX(8)						      System Manager's Manual							 APPROX(8)

NAME

       approx - proxy server for Debian archive files

SYNOPSIS

       approx [OPTION]...

DESCRIPTION

       approx responds to HTTP requests made by apt-get(8).  It maintains a cache of Debian archive files that have been previously downloaded, so
       that it can respond with a local copy when possible.  If a file not in the cache is requested, approx will download it from a remote Debian
       repository and deliver the contents to the client, simultaneously caching it for future use.

       Over  time,  the approx server cache will grow to contain multiple, unneeded versions of Debian packages.  The approx-gc(8) program removes
       these from the cache.

OPTIONS

       -c file, --config file
	      Specify an additional configuration file.  May be used multiple times.

USAGE

       approx is invoked by inetd(8).

EXAMPLES

       Suppose that a client machine's /etc/apt/sources.list file contains the following lines:

	      deb     http://apt:9999/debian	testing main
	      deb     http://apt:9999/security	testing/updates main
	      deb-src http://apt:9999/debian	unstable main

       In this example, apt is the hostname of the approx server machine on the local network.	Each distribution, such as "debian" or "security",
       is mapped to a remote repository in the approx server's configuration file.

       For example, the approx.conf file on the approx server might contain the lines

	      debian   http://ftp.debian.org/debian
	      security http://security.debian.org

       The mapping scheme is very simple.  If the approx.conf file contains the line

	      repository     http://remote-host/initial/path

       then any request to the approx server of the form

	      http://approx-server/repository/rest/of/URL

       is rewritten to

	      http://remote-host/initial/path/rest/of/URL

       when there is a "cache miss", and that file is cached as

	      /var/cache/approx/repository/rest/of/URL

       (Note  that  the repository name on the left-hand side is not included in the rewritten URL unless it is explicitly mentioned in the right-
       hand side's initial path.)

FILES

       /etc/approx/approx.conf
	      Configuration file for approx and related programs.

       /var/cache/approx
	      Default cache directory for archive files.

SEE ALSO

       approx.conf(5), inetd(8), approx-import(8), approx-gc(8), apt-get(8), sources.list(5)

AUTHOR

       Eric Cooper <ecc@cmu.edu>

								     May 2011								 APPROX(8)