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)