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NAME

       approx - proxy server for Debian archive files

SYNOPSIS

       approx

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.

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
              Cache directory for archive files.

SEE ALSO

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

AUTHOR

       Eric Cooper <ecc@cmu.edu>

                                  March 2009