MULTISTRAP(1) User Contributed Perl Documentation MULTISTRAP(1)
Name
multistrap - multiple repository bootstraps
Synopsis
multistrap [-a ARCH] [-d DIR] -f CONFIG_FILE
multistrap [--simulate] -f CONFIG_FILE
multistrap -?|-h|--help|--version
Options
-?|-h|--help|--version - output the help text and exit successfully.
--dry-run - collate all the configuration settings and output a bare summary.
--simulate - same as --dry-run
(The following options can also be set in the configuration file.)
-a|--arch - architecture of the packages to put into the multistrap.
-d|--dir - directory into which the bootstrap will be installed.
-f|--file - configuration file for multistrap [required]
-s|--shortcut - shortened version of -f for files in known locations.
--tidy-up - remove apt cache data, downloaded Packages files and the apt package cache. Same as cleanup=true.
--no-auth - allow the use of unauthenticated repositories. Same as noauth=true
--source-dir DIR - move the contents of var/cache/apt/archives/ from inside the chroot to the specified external directory, then add the
Debian source packages for each used binary. Same as retainsources=DIR If the specified directory does not exist, nothing is done. Requires
--tidy-up in order to calculate the full list of source packages, including dependencies.
Description
multistrap provides a debootstrap-like method based on apt and extended to provide support for multiple repositories, using a configuration
file to specify the relevant suites, architecture, extra packages and the mirror to use for each bootstrap.
The aim is to create a complete bootstrap / root filesystem with all packages installed and configured, instead of just the base system.
In most cases, users will need to create a configuration file for each different multistrap usage.
Example configuration:
[General]
arch=armel
directory=/opt/multistrap/
# same as --tidy-up option if set to true
cleanup=true
# same as --no-auth option if set to true
# keyring packages listed in each bootstrap will
# still be installed.
noauth=false
# extract all downloaded archives (default is true)
unpack=true
# whether to add the /suite to be explicit about where apt
# needs to look for packages. Default is false.
explicitsuite=false
# enable MultiArch for the specified architectures
# default is empty
multiarch=
# aptsources is a list of sections to be used
# the /etc/apt/sources.list.d/multistrap.sources.list
# of the target. Order is not important
aptsources=Debian
# the bootstrap option determines which repository
# is used to calculate the list of Priority: required packages
# and which packages go into the rootfs.
# The order of sections is not important.
bootstrap=Debian
[Debian]
packages=
source=http://ftp.uk.debian.org/debian
keyring=debian-archive-keyring
suite=lenny
This will result in a completely normal bootstrap of Debian lenny from the specified mirror, for armel in '/opt/multistrap/'. (This
configuration is retained in the package as /usr/share/multistrap/lenny.conf)
Specify a package to extend the multistrap to include that package and all dependencies of that package.
Specify more repositories for the bootstrap by adding new sections. Section names need to be listed in the bootstrap general option for
the packages to be included in the bootstrap.
Specify which repositories will be available to the final system at boot by listing the section names in the aptsources general option,
e.g. to exclude some internal sources or when using a local mirror when building the rootfs.
Section names are case-insensitive.
All dependencies are resolved only by apt, using all bootstrap repositories, to use only the most recent and most suitable dependencies.
Note that multistrap turns off Install-Recommends so if the multistrap needs a package that is only a Recommended dependency, the
recommended package needs to be specified in the packages line explicitly. See "Explicit suite specification" for more information on
getting specific packages from specific suites.
'Architecture' and 'directory' can be overridden on the command line. Some other general options also have command line options.
Shortcuts
In a similar manner to "debootstrap", "multistrap" supports referring to configuration files in known locations by shortcuts. When using
the "--shortcut" option, "multistrap" will look for files in /usr/share/multistrap and then /etc/multistrap.d/, appending a '.conf' suffix
to the specified shortcut.
These two commands are equivalent:
$ sudo multistrap -s sid
$ sudo multistrap -f /usr/share/multistrap/sid.conf
Note that "multistrap" will still fail if the configuration file itself does not set the directory or the architecture.
Repositories
"aptsources" lists the sections which should be used to create the /etc/apt/sources.list.d/multistrap.list apt sources in the final system.
Not all "aptsources" have to appear in the "bootstrap" section if you have some internal or local sources which are not accessible to the
installed root filesystem.
"bootstrap" lists the sections which will be used to create the multistrap itself. Only packages listed in "bootstrap" will be downloaded
and unpacked by multistrap.
Make sure "bootstrap" lists all sections you need for apt to be able to find all the packages to be unpacked for the multistrap.
(Older versions of multistrap supported the same option under the "debootstrap" name - this spelling is still supported but new
configuration files should be "bootstrap" instead.
General settings:
'arch' can be overridden on the command line using the "--arch" option.
'directory' specifies the top level directory where the bootstrap will be created - it is not packed into a .tgz once complete.
'bootstrap' lists the Sections which will be used to specify the packages which will be downloaded (and optionally unpacked) into the
bootstrap.
'aptsources' lists the Sections which will be used to specify the apt sources in the final system, e.g. if you need to use a local
repository to generate the rootfs which will not be available to the device at runtime, list that section in "bootstrap" but not in
"aptsources".
If you want a package to be in the rootfs, it must be specified in the "bootstrap" list under General.
The order of section names in either list is not important.
As with debootstrap, multistrap will continue after errors, as long as the configuration file can be correctly parsed.
multistrap also implements the machine:variant support originally used in Emdebian Crush, although in a different implementation. Using the
cascading configuration support, particular machine:variant combinations can be supported by simple changes on the command line.
Setting "tarballname" to true also packs up the final filesystem into a tarball.
Note that multistrap ignores any unrecognised options in the config file - this allows for backwards-compatible behaviour as well as
overloading the multistrap config files to support other tools (like pbuilder). Use the "--simulate" option to see the combined
configuration settings.
However, if the config file itself cannot be parsed, multistrap will abort. Check that the config file has a key and a value for each line,
other than comments. Values must all on the same line as the key.
Section settings
[Debian]
packages=
source=http://ftp.uk.debian.org/debian
keyring=debian-archive-keyring
suite=lenny
The section name (in [] brackets) needs to be unique for this configuration file and any configuration files which this file includes.
Section names are case insensitive (all comparisons happen after conversion to lower case).
'packages' is the list of packages to be added when this Section is listed in "bootstrap" - all package names must be listed on a single
line or the file will fail to parse. One alternative is to define your list of packages as multiple groups with packages separated on a
functional / dependency basis, e.g. base, Xorg, networking etc. and list each group under 'bootstrap'.
bootstrap=base networking
[base]
packages=udev mtd-utils
source=http://www.emdebian.org/grip
keyring=emdebian-archive-keyring
suite=lenny
[networking]
packages=netbase ifupdown iproute net-tools samba
source=http://www.emdebian.org/grip
keyring=emdebian-archive-keyring
suite=lenny
As a special case, "multistrap" also supports multiple packages keys per section, one line for each. Other keys cannot be repeated in this
manner.
[Emdebian]
packages=udev mtd-utils netbase ifupdown iproute
packages=busybox net-tools samba
source=http://www.emdebian.org/grip
keyring=emdebian-archive-keyring
suite=lenny
'source' is the apt source to use for this Section. To use a local source on the same machine, ensure you use "copy://" not "file://", so
that apt is told to copy the packages into the rootfs instead of assuming it can try to download them later - because that "later" will
never actually happen.
'keyring' lists the package which contains the key used by the source listed in this Section. If no keyring is specified, the "noauth"
option must be set to true. See Secure Apt.
'suite' is the suite to use from this source. Note that this should be the suite, not the codename.
Suites change from time to time: (oldstable, stable, testing, sid) The codename (etch, lenny, squeeze, sid) does not change.
Secure Apt
To use authenticated apt repositories, multistrap needs to be able to install an appropriate keyring package from the existing apt sources
outside the multistrap environment into the destination system. Unfortunately, keyring packages cannot be downloaded from the repositories
specified in the multistrap configuration - this is because "apt" needs the keyring to be updated before being able to use repositories not
previously known.
If relevant packages exist, specify them in the 'keyring' option for each repository. multistrap will then check that apt has already
installed this package so that the repository can be authenticated before any packages are downloaded from it.
Note that all repositories to be used with multistrap must be authenticated or apt will fail. Similarly, secure apt can only be disabled
for all repositories (by using the --no-auth command line option or setting the general noauth option in the configuration file), even if
only one repository does not have a suitable keyring available.
The keyring package(s) will also be installed inside the multistrap environment to match the installed apt sources for the multistrap.
State
multistrap is stateless - if the directory exists, it will simply proceed as normal and apt will try to pick up where it left off.
Root Filesystem Configuration
multistrap unpacks the downloaded packages but other stages of system configuration are not attempted. Examples include:
/etc/inittab
/etc/fstab
/etc/hosts
/etc/securetty
/etc/modules
/etc/hostname
/etc/network/interfaces
/etc/init.d
/etc/dhcp3
Any device-specific device nodes will also need to be created using MAKEDEV or "device-table.pl" - a helper script that can work around
some of the issues with MAKEDEV. device-table.pl requires a device table file along the lines of the one in the mtd-utils source package.
See /usr/share/doc/multistrap/examples/device_table.txt
Once multistrap has successfully created the basic file and directory layout, other device-specific scripts are needed before the
filesystem can be packaged up and installed onto the target device.
Once installed, the packages themselves need to be configured using the package maintainer scripts and "dpkg --configure -a", unless this
is a native multistrap.
For "dpkg" to work, /proc and /sysfs must be mounted (or mountable), /dev/pts is also recommended.
See also: http://wiki.debian.org/Multistrap
Environment
To configure the unpacked packages (whether in native or cross mode), certain environment variables are needed:
Debconf needs to be told to accept that user interaction is not desired:
DEBIAN_FRONTEND=noninteractive DEBCONF_NONINTERACTIVE_SEEN=true
Perl needs to be told to accept that no locales are available inside the chroot and not to complain:
LC_ALL=C LANGUAGE=C LANG=C
Then, dpkg can configure the packages:
chroot method (PATH = top directory of chroot):
DEBIAN_FRONTEND=noninteractive DEBCONF_NONINTERACTIVE_SEEN=true
LC_ALL=C LANGUAGE=C LANG=C chroot /PATH/ dpkg --configure -a
at a login shell:
# export DEBIAN_FRONTEND=noninteractive DEBCONF_NONINTERACTIVE_SEEN=true
# export LC_ALL=C LANGUAGE=C LANG=C
# dpkg --configure -a
(As above, dpkg needs /proc and /sysfs mounted first.)
Native mode - multistrap
multistrap was not intended for native support, it was developed for cross architecture support. In order for multiple repositories to be
used, multistrap only unpacks the packages selected by apt.
In native mode, various post-multistrap operations are likely to be needed that debootstrap would do for you:
1. copy /etc/hosts into the chroot
2. clean the environment to unset LANGUAGE, LC_ALL and LANG
to silence nuisance perl warnings that obscure other errors
(An alternative to unset the localisation variables is to add locales to your multistrap configuration file in the 'packages' option.
A native multistrap can be used directly with chroot, so "multistrap" runs "dpkg --configure -a" at the end of the multistrap process,
unless the ignorenativearch option is set to true in the General section of the configuration file.
Daemons in chroots
Depending on which system you using to provide the packages for "multistrap", native chroots should generally not allow daemons to start
inside the chroot. Use the /usr/share/multistrap/chroot.sh as your "setupscript" or include that script in your own setup script.
setupscript=/usr/share/multistrap/chroot.sh
chroot.sh copes with systems using sysvinit and upstart.
See also
http://people.debian.org/~hmh/invokerc.d-policyrc.d-specification.txt
Cascading configuration
To support multiple variants of a basic (common) configuration, "multistrap" allows configuration files to include other (more general)
configuration files. i.e. the most detailed / specific configuration file is specified on the command line and that file includes another
file which is shared by other configurations.
Base file:
/usr/share/multistrap/crosschroot.conf
Variations:
/usr/share/multistrap/armel.conf
Specifying just the armel.conf file will get the rest of the settings from crosschroot.conf so that common changes only need to be made in
a single file.
It is strongly recommended that any changes to the configuration files involved in any particular cascade are tested using the "--simulate"
option to multistrap which will output a summary of the options that have been set once the cascade is complete. Note that multistrap does
not warn you if a configuration file contains an unrecognised option (for future compatibility with backported configurations), so a simple
typo can result in an option not being set.
Machine:variant support
The old packages.conf variables from emsandbox can all be converted into "multistrap" configuration variables. The machine:variant support
in "multistrap" concentrates on the scripts, config.sh and setup.sh
Note: machine:variant support is likely to be replaced by the hook functionality described below.
Once "multistrap" has unpacked the downloaded packages, the "setup.sh" can be called, passing the location and architecture of the root
filesystem, so that other fine tuning can take place. At this stage, any operations inside a foreign architecture rootfs must not try to
execute any binaries within the rootfs. As the final stage of the multistrap process, "config.sh" is copied into the root directory of the
rootfs.
One advantage of using machine:variant support is that the entire rootfilesystem can be managed by a single call to multistrap - this is
useful when building root filesystems in userspace.
To enable machine:variant support, specify the path to the scripts to be called in the variant configuration file (General section):
[General]
include=/path/to/general.conf
setupscript=/path/to/setup.sh
configscript=/path/to/config.sh
Restricting package selection
"multistrap" includes Required packages by default, the current list of packages on your own machine can be seen using:
grep-available -FPriority 'required' -sPackage
(The actual list is calculated from the downloaded Packages files and may differ from the output of "grep-available".)
If the OmitRequired option is set to true, these packages will not be added - whilst useful, this option can easily lead to a useless
rootfs. Only the packages specified manually in the configuration files will be used in the calculations - dependencies of those packages
will be added but no others.
Adding Priority: important packages
"multistrap" can imitate "debootstrap" by automatically adding all packages from all sections where the downloaded Packages file lists the
package as Priority: important. The default is not to add such packages unless individually included in a "packages=" option in a section
specified in the "bootstrap" general option. To add all such packages, set the addimportant option to true in the general section.
addimportant=true
Priority: important can only operate for all sections listed in the "bootstrap" option. This may cause some confusion when mixing suites.
It is not possible to enable addimportant and omitrequired in the same configuration. "multistrap" will exit with error code 7 if any
configuration results in addimportant and omitrequired both being set to true. (This includes the effects of including other configuration
files.)
Recommends behaviour
The Debian default behaviour after the Lenny release was to consider recommended packages as extra packages to be installed when any one
package is selected. Recommended packages are those which the maintainer considers that would be present on "most" installations of that
package and allowing Recommends means allowing Recommends of recommended packages and so on.
The multistrap default is to turn recommends OFF.
Set the allowrecommends option to true in the General section to use typical Debian behaviour.
Default release
If your system specifies a default-release for apt, this can cause problems when trying to create a bootstrap which does not include the
default suite. To counter this, "multistrap" sets a wildcard for the Default Release within the bootstrap. See also: apt preferences.
Explicit suite specification
Sometimes, apt needs to be told to get a particular package from a particular suite, ignoring a more recent version in another suite in the
same set of sources.
"multistrap" can operate with and without the explicit suite option, the default is to let apt use the most recent version from the
collection of specified bootstrap sources.
Explicit suite specification has no effect on the final installed system - if your aptsources includes a repository which in turn includes
a newer version of the package(s) specified explicitly, the next "apt-get upgrade" on the device will bring in the newer version.
Also, when specifying packages to get from a specific suite, apt will also try and ensure that the dependencies for that package are also
from the same suite and this can cause apt to be unable to resolve the complete set of dependencies. In this situation, being explicit
about one package selection may require being explicit about some (not necessarily all) of the dependencies of that package as well.
When using this support in Lenny, ensure that each section uses the suite (oldstable, stable, testing, sid) and not the codename (etch,
lenny, squeeze, sid) in the "suite" configuration item as the version of apt in Lenny and previous cannot use the codename.
To test, on Lenny, try:
$ sudo apt-get install apt/stable
Compare with
$ sudo apt-get install apt/lenny
When using explicitsuite, take care in using stable-proposed-updates or other temporary locations - if the package migrates into another
suite and is removed from the temporary suite (as with *-proposed-updates), multistrap will not be able to find the package.
Explicit suite handling can be very hard to get right. In general, it is best to create a small bootstrap chroot of your native arch, then
chroot into it, add the relevant apt sources and work out exactly what commands are necessary to get the correct mix of packages. Avoid
specifying explicit versions to sort out problems, work with suites only. Apt preferences / pinning may be useful here, see Apt
preferences.
Apt preferences
If a suitable file is listed in the aptpreferences option of the General section of the configuration file, this file will be copied into
the apt preferences directory of the bootstrap before apt is first used.
When an apt preferences file is provided, the "Default-Release" behaviour of "multistrap" is disabled.
As with other external scripts and files, the content of the apt preferences file is beyond the scope of this manpage. "multistrap" does
not try to verify the supplied file other than ensuring that it can be read.
Omitting deb-src listings
Some multistrap environments do not need access to the Debian sources of packages being installed, typically this is required when
preparing a build (or cross-build) chroot using multistrap.
To turn off this additional source (and save both download time and apt-cache size), use the omitdebsrc field in each Section.
[Baked]
packages=
source=http://www.emdebian.org/baked
keyring=emdebian-archive-keyring
suite=testing
omitdebsrc=true
omitdebsrc is necessary when using packages from debian-ports where packages do not have sources, except "unreleased".
fakeroot
Foreign architecture bootstraps can operate under "fakeroot" ("multistrap" is designed to do as much as it can within a single call to make
this easier) but the configuration stage which normally happens with a native architecture bootstrap requires "chroot" and "chroot" itself
will not operate under "fakeroot".
Therefore, if "multistrap" detects that "fakeroot" is in use, native mode configuration is skipped with a reminder warning.
The same problem applies to "apt-get install" and therefore the installation of the keyring package on the host system is also skipped if
fakeroot is detected.
Handling problematic packages
Sometimes, a particular package will fail to even unpack properly if other packages have not already been unpacked. This can happen if dpkg
diversions are not setup correctly or if the package Pre-Depends on an executable in another package.
Multistrap offers two ways to handle these problems. A package can be listed as "reinstall" or as "additional". Each section in the
"multistrap" configuration file can have a single "reinstall" or "additional" listing or both.
Reinstall means that the package will be downloaded and unpacked as normal - alongside all the other packages, but will then be reinstalled
at the end by running the "preinst" maintainer script with the "upgrade" argument. "dpkg" will then continue the rest of the configuration
of that package.
Additional adds a second round of "apt-get install" to the multistrap process - after the initial unpacking. The additional package will
then be downloaded and unpacked. If running natively, the additional package is downloaded, unpacked and configured after all the rest of
the packages have been downloaded, unpacked and configured.
Neither "reinstall" nor "additional" should be seen as more than just workarounds and wishlist bugs should be filed in Debian against
packages which require the use of these mechanisms (or the packages which would prevent the particular package from operating normally).
Debconf preseeding
Adding a debconf seed can help in configuring packages to a particular setting instead of the package default when running the
configuration non-interactively. See http://www.debian-administration.org/articles/394 for information on how to create seed files.
Multiple seed files can be specified using the debconfseed field in the [General] section, separated by spaces:
debconfseed=seed1 seed2
Files which do not exist or which cannot be opened will be silently ignored. Check the results of the parsing using the "--simulate" option
to "multistrap".
Hooks
If a hook directory is specified in the General section of the "multistrap" configuration file, the hook scripts which are executable will
be run from outside the multistrap directory at the following stages:
download hooks
Executed before unpacking is started, immediately after the packages have been downloaded. Download hooks are executable scripts in the
specified hook directory with a filename beginning with download.
native hooks
Native hook scripts are executed only in native mode, immediately before starting the configuration of the downloaded packages and again
upon completion of the package configuration. Native hooks will be called the absolute path and the current progress state, start or end.
Native scripts are executable scripts in the specified hook directory with a filename beginning with native.
completion hooks
Executed immediately before the tarball is created or "multistrap" exits if not configured to create a tarball.
Completion scripts are executable scripts in the specified hook directory with a filename beginning with "completion".
Hooks are passed the absolute path to the directory which will be the top level directory of the chroot or multistrap system. Hooks which
cannot be resolved using realpath or which are not executable will be ignored.
All hooks of one type are sorted into alphabetical order before being run.
Note that "multistrap" does not rollback the effects of hooks in the case of errors. However, "multistrap" will report the accumulated
errors as warnings. If a hook exits non-zero, the exit value is converted to a positive number and added to the total warning count,
reported at the end of the operation.
Output
"multistrap" can produce a lot of output - informational messages appear on STDOUT, errors and warnings on STDERR. Calls to "apt" and
"dpkg" respect the same pattern, so it is simple to trim the combined "multistrap" output to just the errors, if desired.
"multistrap" accumulates error states from non-fatal processes within the operation and reports these as warnings on STDERR as well as
exiting with the accumulated error count. This includes hooks which report non-zero exit values.
Bugs
As "multistrap" gets more complex, bugs will creep into the package. Please report all bugs to the Debian BTS using the "reportbug" tool
and please attach all configuration files. If your configuration needs to access local or private apt repositories, please check your
configuration with the latest version of "multistrap" in Debian using the "--simulate" option and include that report in your bug report.
The "--simulate" option output is regularly expanded to help users debug problems in the configuration files.
Please also check (and update) the Multistrap wiki at http://wiki.debian.org/Multistrap and the Multistrap webpage content at
http://www.emdebian.org/multistrap/ before filing bugs. Various people on the debian-embedded@lists.debian.org mailing list and #emdebian
IRC channel on irc.oftc.net can also help if your config file does not parse correctly. You would need to put the "--simulate" output on a
pastebin website and put the URL in your message.
MultiArch support
Multiarch support is experimental - please report issues and file bugs with full details of your setup, the full multistrap config file and
the errors reported.
"multistrap" overrides the existing multiarch support of the external system so that a MultiArch aware system can still create a non-
MultiArch chroot from repositories which do not support all of the architectures supported by the external dpkg.
If multiarch is enabled within the multistrap chroot, "multistrap" writes out the list into /var/lib/dpkg/arch inside the chroot.
For multiple architectures, specify the option once and use a space separated list for the architecture list. Ensure you include what will
be the host architecture of the chroot.
See also http://wiki.debian.org/Multiarch/
[General]
...
multiarch=i386 armel armhf
Each Section will install packages from the base architecture unless the "Architecture" option is specified for particular sections.
[Foreign]
packages=libgcc1 libc6
architecture=armel
source=http://ftp.uk.debian.org/debian
keyring=debian-archive-keyring
suite=sid
In the "--simulate" output, the architecture(s) specified in the MultiArch option will be listed under the "Foreign architectures" listing.
Packages for a specific architecture will be listed as the package name followed by a colon followed by the architecture.
libgcc1:armel libc6:armel
perl v5.14.2 2012-04-20 MULTISTRAP(1)