jk_update(8)jk_updatejk_update(8)NAMEjk_update - a utility to update and cleanup a jail according to changes
on the real system
SYNOPSISjk_update-j <jail>
jk_update-c <section of configfile>
jk_update-v -d -k -j <jail> -s <file to skip> <dir to scan for
updates>
jk_update--verbose --dry-run --hardlink --jail=<jail> --skip=<file to
skip> <dir to scan for updates>
DESCRIPTIONjk_update will compare the files in a jail with the corresponding files
on the real system. If the corresponding file on the real system is
newer, and the file on the real system is different, the file from the
real system will be copied to the jail including any required libraries
just like jk_cp would do. Files that do not exist on the real system
will be deleted in the jail.
jk_update works well to pass security updates on the real system to a
jail. jk_update does not work well with larger upgrades on the real
system. In that case files are often replaced by other files in which
case jk_update will delete the old file but not copy the new file.
Avoid unwanted updates or cleanups
To avoid unwanted updates, or to avoid files being deleted, files or
directories can be skipped by jk_update, either by specifying them on
the commandline or by specifying them in the configfile.
Directories to include in the update
By default jk_update will scan /usr, /bin, /opt, and /lib for updates.
If one or more arguments is passed as directories to update, these
default directries are not scanned, unless they are part of the argu‐
ments. The default directories can also be set in the config file.
jk_update-j <jail> will scan <jail>/usr, <jail>/bin, <jail>/opt, and
<jail>/lib, while jk_update-j <jail> /bin will only scan <jail>/bin
EXAMPLE
An example configfile could look like this:
[/home/testchroot]
skips = /usr/bin/myscript
hardlinks = 1
directories = /usr, /bin, /lib
[/home/otherjail]
skips = /usr/share/firefox, /usr/bin/firefox, /usr/lib/firefox
where the options have the following meaning:
skips
the files and directories to skip
hardlinks
a boolean whether to use hardlinks (1) or copy the files (0)
directories
specifies the directories to include in the update.
WARNING
If you have changed files in the jail, it is recommended to do a "dry
run" first and see what jk_update will do. jk_update does now know if a
file is manually changed or not. If a file in the jail is older and
different from the file on the real system it is updated. If a file in
the jail does not have an equivalent on the real system it is deleted.
Use the skip option to exclude any files that you changed or added man‐
ually.
OPTIONS-v --verbose
Will give verbose output
-h --help
The help screen
-c <section in configfile> --configsection=<section in configfile>
The jail to update
-j <jail> --jail=<jail>
The jail to update
-d --dry-run
Do a "dry run". Show what will be done but don't do anything.
-k --hardlink
Try to create hardlinks instead of copying the files when updat‐
ing
-s <file to skip> --skip <file to skip>
Do not update this file. The argument can either be the path in
the jail or the path on the real system. In order to skip multi‐
ple files, use this option multiple times.
SEE ALSOjailkit(8)jk_check(8)jk_chrootlaunch(8)jk_chrootsh(8)jk_cp(8)jk_init(8)jk_jailuser(8)jk_list(8)jk_lsh(8)jk_procmailwrapper(8)jk_socketd(8)jk_uchroot(8)chroot(2)COPYRIGHT
Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Olivier
Sessink
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
JAILKIT 07-02-2010 jk_update(8)
