Index of /pandora/schroot

Name	Last modified	Size	Description

Parent Directory		-
man/	2012-06-22 17:54	-
README.html	2012-06-22 17:52	5.6K	schroot for the Pandora
schroot-1.5.4-1-pand2.tar.gz	2012-06-22 17:36	870K
schroot-1.5.4-1-pand1.tar.gz	2012-06-16 06:05	872K
debootstrap-1.0.40-pand1.tar.gz	2012-06-15 02:35	58K

schroot for the Pandora

This is a nearly full port of the schroot-Debian package. The following features are disabled:

block-device support
lvm-snapshot support
btrfs-snapshot support

But those are probably not really useful on the Pandora anyway.

As I don't think a PND is the best option for a system utility, the package has to be installed in /opt.

'schroot' has many features. It can use image files, setup overlay filesystems on entering, keep important files (resolv.conf, /etc/passwd, etc.) in sync, mount a fixed directory structure or execute a custom script upon entering a chroot and manage many different chroots.

If you want to get more information read the man-pages (they are also included in the packages although there is no 'man' command on the Pandora) or visit http://wiki.debian.org/Schroot or http://wiki.ubuntuusers.de/schroot for more details.

I also configured the package so that it mounts and unmounts everything under /media (e.g. your SD-Cards) in the chroot automatically. Unfortunately the subtree mount options on the Pandora are broken and so filesystems that were already mounted when you entered a chroot will not be automatically unmounted. If you want to eject an SD-Card that was mounted when you entered the chroot you will have to manually unmount it in the chroot first.

Changelog

schroot-1.5.4-1-pand1.tar.gz: Initial release.
schroot-1.5.4-1-pand2.tar.gz: Should now work without the pandora-mediabind.sh script installed (although automatic SD-card (un)mounting will not work within the chroots).; If no /media directory is present in the chroot, it will be created. (Fixes issue with missing /media directory in fresh squeeze chroots.); Copying of the nssdatabase files will now skip files that are not present on the host. (Fixes issue with /etc/networks not being installed on the Pandora by default.)

Installation

Create the directory where you want to install schroot and possibly debootstrap. Let's say you want to install it in /media/SDCard/opt. Create the directory and a symlink from /opt:

$ mkdir /media/SDCard/opt
$ sudo ln -s /media/SDCard/opt /

If your OS is already on an SD-Card, you can create /opt as a regular directory, of course.

IMPORTANT:The location where schroot is to be installed must be a proper filesystem with working permissions as the executable needs the setuid bit set. So best use ext4/3/2. FAT will not work. I don't know about NTFS, but I doubt it.

Unpack the tar-archive in /opt. This has to be done with root priviledges as the schroot executable has the setuid flag set:

$ cd /opt
$ sudo tar xfvz /tmp/schroot-1.5.4-1-pand2.tar.gz

Now install the startup script that makes the automatic (un)mounting possible (don't overlook the '.' at the end of the second command):

$ sudo cp /opt/schroot/etc/init.d/pandora-mediabind.sh /etc/init.d
$ sudo update-rc.d pandora-mediabind.sh start 2 S .

If you also want to install debootstrap:

$ cd /opt
$ tar xfvz /tmp/debootstrap-1.0.40-pand1.tar.gz

Now reboot your Pandora and that's it.

Optional comfort feature:

To setup your PATH variable and to get a nice indication in which chroot you are, you can add the following two lines at the end of your ~/.profile file with your favourite text editor:

export PATH=$PATH:/opt/schroot/bin
export PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '

Usage

Here is a very brief introduction to get a basic working Debian squeeze chroot in "/media/SDCard/chroot/squeeze". You will need at least 250MB of free disk space. More is recommended if you actually want to install something useful.

$ sudo -i
# mkdir -p /media/SDCard/chroot/squeeze
# cat > /opt/schroot/etc/schroot/chroot.d/squeeze << EOF
[squeeze]
description=Debian squeeze Installation
aliases=default
type=directory
directory=/media/SDCard/chroot/squeeze
users=<YOURUSERNAME>
root-groups=root
profile=pandora
personality=linux
preserve-environment=true
EOF
# /opt/debootstrap/sbin/debootstrap --arch=armel squeeze /media/SDCard/chroot/squeeze

Now wait. And wait. And wait some more. It took me about 33 minutes with an ext4 partition on a Class 6 card. After the process is finished you will have a working but very spartanic chroot in /media/SDCard/chroot/squeeze.

The next step should be to get sudo installed:

$ sudo /opt/schroot/bin/schroot -c squeeze apt-get update
$ sudo /opt/schroot/bin/schroot -c squeeze aptitude install sudo

Now you can enter a chroot as your regular user just by typing "schroot -c squeeze" (if you have set up your PATH correctly). You can even omit the "-c squeeze" if you followed the example and have an "aliases=default" line in your chroot description.

You can also start programs directly in a chroot:

$ schroot apt-cache search mplayer
$ schroot sudo aptitude install mplayer
$ schroot mplayer /media/SDCard/video.avi

It is also possible to associate filetypes with programs in a chroot.