NAME
acngfs - Virtual file system for use with apt-cacher-ng
SYNOPSIS
acngfs BaseURL ProxyHost MountPoint [ -o 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:
+o 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)
+o Local programs (e.g. apt, dpkg) need to read the packages from a
local filesystem
+o When reading, certain files might need to be fetched in
background (or updated) and this process needs to be triggered
somehow
+o Network latency and speed are not relevant, e.g. accessing apt-
cacher-ng via localhost connection (with the current
implementation, this is very important since all data is
transfered twice internally, for technical reasons).
+o The proxy service can work efficiently with many requests for
small data ranges (apt-cacher-ng, for example)
+o Pattern matching on paths is sufficient to distinguish file and
directory names
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
localhost:3142 /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.
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
reading is allowed (only 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 will flood log files with many requests of 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.