NAME

       acngfs - Virtual file system for use with apt-cacher-ng

SYNOPSIS

       acngfs BaseURL MountPoint [ proxy=ProxyHost:ProxyPort ] [ cachedir=CachePath ] [ more_acng=settings] [FUSE Mount Options]

DESCRIPTION

       acngfs  is  a  FUSE  based  filesystem  which  represents  files downloadable via HTTP as part of a local
       filesystem. It has been developed for very specific purposes and is not intended to be a general  purpose
       HTTP filesystem.

       The main use case for acngfs is a situation where:

       •      The  files  must  not  be stored on extra space on the user's system (e.g. because of insufficient
              disk space to make a temporary copy of downloaded files)

       •      Local programs (e.g. apt, dpkg) need to read the packages from a local filesystem

       •      When reading, certain files might need to be fetched in background (or updated) and  this  process
              needs to be triggered somehow

       •      Network latency and speed are not relevant, e.g. accessing apt-cacher-ng via localhost connection

       •      The  proxy  service  can work efficiently with many requests for small data ranges (apt-cacher-ng,
              for example)

       •      Pattern matching on paths is sufficient to distinguish file and directory names

       If the apt-cacher-ng instance happens to run on the same system as acngfs  or  its  cache  repository  is
       mounted  via  fast  remote  file system, this cache repository can be optionally specified as alternative
       source path. In this cache, acngfs will attempt  to  read  files  directly  from  this  filesystem  where
       possible,  reducing  network  latency and avoiding additional load of apt-cacher-ng server. The directory
       levels of BaseURL and CachePath should match.

EXAMPLES

       Typical use may be to let apt/dpkg use package file like they are present  on  the  local  filesystem  so
       there is no need to download them. In sources.list, the source appears as a file:/ type URL, like:

       deb file:/var/local/acngfs_debian unstable main contrib

       and the filesystem backend is prepared with a command like:

       /usr/lib/apt-cacher-ng/acngfs http://ftp.uni-kl.de/debian proxy=cacheBox:3142 /var/local/acngfs_debian -o
       allow_root

       or for a locally installed apt-cacher-ng with common Debian cache repository  stored  in  /var/cache/apt-
       cacher-ng/debrep:

       /usr/lib/apt-cacher-ng/acngfs         http://ftp.uni-kl.de/debian         /var/cache/apt-cacher-ng/debrep
       proxy=localhost:3142 cachedir=/var/local/acngfs_debian -o allow_root

OPTIONS

       The command-line options supported by acngfs are:

       BaseURL
              Remote mirror to be used as real source, like http://ftp2.de.debian.org/debian. NOTE:  the  mirror
              subdirectory  part (like debian) should be added either to BaseURL or to the path in sources.list,
              not to both.

       ProxyURL
              Complete or simplified host and port specification of the proxy server, http://localhost:3142.

       CachePath
              Optional hint, a directory path pointing to the internal cache subdirectory of apt-cacher-ng where
              it  stores  data  downloaded  from  BaseURL.  For  more  details see apt-cacher-ng manual, chapter
              "Advanced configuration".

       mountpoint
              Directory representing the URL in the local filesytem.

       --help Print a help summary and additional FUSE application options

       FuseOptions
              Various options for the FUSE subsystem to control filesystem behaviour. See --help output and FUSE
              documentation for more details.

FILES

       /usr/lib/apt-cacher-ng/acngfs
              Executable binary documented in this manual page

NOTES

       Permissions  of the files are important when using mounting when sharing data with other users (including
       root!). To mount as user and let root use the package management tools (apt, dpkg), one may need  to  use
       FUSE options like in the following example:

       acngfs http://ftp.uni-kl.de/debian http://localhost:3142 /mnt/misc -o allow_root

       See FUSE documentation for details about file permissions representation.

BUGS

       Software is still experimental, use at your own risk!

       There  are  natural  limitations  on capabilities of the FS: no directory browsing is allowed (only blind
       descending), permissions of files are inherited from the mount point as well as other properties  of  the
       filesystem.

       Should  be used with apt-cacher-ng version 0.2pre2 or newer; otherwise it could flood log files with many
       requests from small file chunks.

SEE ALSO

       apt-cacher-ng(8), fusermount(1)

       For more information on Apt-Cacher NG, read the User Manual which can be  found  either  in  the  doc/pdf
       directory  of the software source package or installed in the documentation directory of apt-cacher-ng by
       your distribution.