acngfs(8)

1acngfs(8)                        Eduard Bloch                        acngfs(8)
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NAME

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

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

12       acngfs  is  a FUSE based filesystem which represents files downloadable
13       via HTTP as part of a local filesystem. It has been developed for  very
14       specific  purposes  and  is  not  intended to be a general purpose HTTP
15       filesystem.
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17       The main use case for acngfs is a situation where:
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19       •      The files must not be stored on extra space on the user's system
20              (e.g.  because  of  insufficient  disk space to make a temporary
21              copy of downloaded files)
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23       •      Local programs (e.g. apt, dpkg) need to read the packages from a
24              local filesystem
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26       •      When  reading,  certain  files might need to be fetched in back‐
27              ground (or updated) and this process needs to be triggered some‐
28              how
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30       •      Network  latency and speed are not relevant, e.g. accessing apt-
31              cacher-ng via localhost connection
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33       •      The proxy service can work efficiently with  many  requests  for
34              small data ranges (apt-cacher-ng, for example)
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36       •      Pattern  matching on paths is sufficient to distinguish file and
37              directory names
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39       If the apt-cacher-ng instance happens to run on the same system as  ac‐
40       ngfs  or  its  cache repository is mounted via fast remote file system,
41       this cache repository can be optionally specified as alternative source
42       path.  In  this  cache, acngfs will attempt to read files directly from
43       this filesystem where possible, reducing network latency  and  avoiding
44       additional  load  of  apt-cacher-ng  server.  The  directory  levels of
45       BaseURL and CachePath should match.
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EXAMPLES

48       Typical use may be to let apt/dpkg  use  package  file  like  they  are
49       present  on  the local filesystem so there is no need to download them.
50       In sources.list, the source appears as a file:/ type URL, like:
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52       deb file:/var/local/acngfs_debian unstable main contrib
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54       and the filesystem backend is prepared with a command like:
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56       /usr/lib/apt-cacher-ng/acngfs               http://ftp.uni-kl.de/debian
57       proxy=cacheBox:3142 /var/local/acngfs_debian -o allow_root
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59       or  for  a  locally  installed  apt-cacher-ng  with common Debian cache
60       repository stored in /var/cache/apt-cacher-ng/debrep:
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62       /usr/lib/apt-cacher-ng/acngfs               http://ftp.uni-kl.de/debian
63       /var/cache/apt-cacher-ng/debrep  proxy=localhost:3142 cachedir=/var/lo‐
64       cal/acngfs_debian -o allow_root
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OPTIONS

67       The command-line options supported by acngfs are:
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69       BaseURL
70              Remote mirror to be used as real source, like http://ftp2.de.de‐
71              bian.org/debian.  NOTE:  the  mirror subdirectory part (like de‐
72              bian) should be added either  to  BaseURL  or  to  the  path  in
73              sources.list, not to both.
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75       ProxyURL
76              Complete  or simplified host and port specification of the proxy
77              server, http://localhost:3142.
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79       CachePath
80              Optional hint, a directory path pointing to the  internal  cache
81              subdirectory  of  apt-cacher-ng  where it stores data downloaded
82              from BaseURL. For more details see apt-cacher-ng manual, chapter
83              "Advanced configuration".
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85       mountpoint
86              Directory representing the URL in the local filesytem.
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88       --help Print a help summary and additional FUSE application options
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90       FuseOptions
91              Various options for the FUSE subsystem to control filesystem be‐
92              haviour. See --help output and FUSE documentation for  more  de‐
93              tails.
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FILES

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

100       Permissions of the files are important when using mounting when sharing
101       data with other users (including root!). To mount as user and let  root
102       use  the package management tools (apt, dpkg), one may need to use FUSE
103       options like in the following example:
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105       acngfs http://ftp.uni-kl.de/debian http://localhost:3142  /mnt/misc  -o
106       allow_root
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108       See  FUSE  documentation for details about file permissions representa‐
109       tion.
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BUGS

112       Software is still experimental, use at your own risk!
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114       There are natural limitations on capabilities of the FS:  no  directory
115       browsing  is  allowed (only blind descending), permissions of files are
116       inherited from the mount point as  well  as  other  properties  of  the
117       filesystem.
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119       Should  be  used with apt-cacher-ng version 0.2pre2 or newer; otherwise
120       it could flood log files with many requests from small file chunks.
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