Development Team/Chroot

Status

• Debian chroot construction has been automated: see puritan-sugar.tar.bz2 and its README -- Michael Stone 20:33, 1 August 2009 (UTC)
• Sugar continues to run happily in Squeeze chroots. --Michael Stone 16:30, 3 July 2009 (UTC)
• Sugar is now somewhat runnable from chroots. Jaunty and Squeeze have been tested recently; Fedora has not. --Michael Stone 22:21, 23 May 2009 (UTC)

Chroot Construction

There are lots of ways to create appropriate chroots; e.g. by hand, with debootstrap, with mock, etc.

Here are some ideas to help you get started:

Ubuntu jaunty chroot

With recent versions of debootstrap, in order to get a working chroot, you want something like:

export CHROOT=`pwd`/jaunty-root
sudo debootstrap --arch i386 jaunty $CHROOT http://ubuntu.media.mit.edu/ubuntu/
sudo chroot $CHROOT /bin/bash -l
mount -t proc proc /proc
mount -t devpts devpts /dev/pts

Debian squeeze chroot

With debootstrap, in order to get a working chroot, you want something like:

export CHROOT=`pwd`/sid-root
sudo debootstrap --arch i386 squeeze $CHROOT http://debian.lcs.mit.edu/debian
sudo chroot $CHROOT /bin/bash -l
# and some of the following:
mount -t tmpfs tmpfs $CHROOT/tmp
mount -t proc proc $CHROOT/proc
mount -t devpts devpts $CHROOT/dev/pts
mount -t selinuxfs selinux $CHROOT/selinux

Reference: http://www.debian.org/doc/manuals/reference/ch-tips.en.html

Note: you can use approx to cache packages across multiple runs for faster testing:

apt-get install approx
echo 'debian http://debian.lcs.mit.edu/debian' >> /etc/approx/approx.conf
/etc/init.d/approx restart
sudo debootstrap --arch i386 squeeze $CHROOT http://localhost:9999/debian

Fedora rawhide chroot

We will use febootstrap to construct our Fedora chroot. Install it with:

yum install febootstrap            # or
apt-get install febootstrap

(Note for Debian users -- Fedora 11 and up require versions of rpm built with fancy features. I have successfully run these instructions with rpm_4.7.1-4_i386, which, at the time, I built from sources in Debian Experimental.)

Then run it like so:

sudo febootstrap fedora-11 ./f11  -- sugar-0.84
sudo febootstrap fedora-12 ./f12  -- sugar-0.85.5, at the time of writing

Gentoo chroot

Well, if you are familiar with regular Gentoo installation process(by using Handbook instead of GUI stuff) you should know how to setup Gentoo chtoot :). Otherwise use these instructions.

• Firstly, you need Gentoo stage tarball. You can borrow it from any mirror (use releases/<platform>/current sub directory).

• Lets think you are using stage3-i686-20090623.tar.bz2, then:

mkdir chroot-gentoo
tar xjpf stage3-i686-20090623.tar.bz2 -C chroot-gentoo
mount -o bind /dev chroot-gentoo/dev
mount -o bind /proc chroot-gentoo/proc
chroot chroot-gentoo /bin/bash

• To install sugar, use sugar-overlay or setup sugar-jhbuild environment(with sugar-overlay you can install git packages as well).

Sugar Installation

jaunty chroot

sed -ie "s/main/main universe/" /etc/apt/sources.list
apt-get update

apt-get install locales
locale-gen "$LANG"
dpkg-reconfigure tzdata

apt-get install sugar sugar-activities

# install your development tools here
 
# patch (hopefully temporary) bugs
sed -ie '114i\\        if not favorites_settings.layout: favorites_settings.layout = favoriteslayout.RingLayout.key' /usr/lib/python2.6/dist-packages/jarabe/desktop/favoritesview.py

squeeze chroot

apt-get update
apt-get install locales
dpkg-reconfigure locales

# edit /etc/hosts

apt-get install education-desktop-sugar

# install your development tools here

# fix broken hippocanvas (Debian bug#522231)
echo "deb-src http://debian.lcs.mit.edu/debian squeeze main" >> /etc/apt/sources.list
# echo "deb-src http://localhost:9999/debian squeeze main" >> /etc/apt/sources.list
apt-get update
apt-get install apt-src devscripts
apt-src install python-hippocanvas
cd *hippo*
DEB_BUILD_OPTIONS=nostrip debuild -us -uc
cd ..
dpkg -i *hippo*.deb

User Accounts

For stupid reasons, it's necessary that Sugar run under a uid inside the chroot which exists as a real account outside the chroot. (Talk to the DBus people.)

Consequently, as root, run something like this both inside and outside the chroot:

groupadd -g 64002 sugar
useradd -m -u 64002 -g sugar -s /bin/bash sugar

D-Bus

Sugar wants to be able to use global state stored in both HAL and NetworkManager, both of which live on the system bus. Consequently, outside the chroot, we need to

sudo mount --bind /var/run/dbus $CHROOT/var/run/dbus

before entering the chroot. (Mock uses unshare() to enter a new mount-point namespace since this makes garbage collection of mountpoints much easier.)

X11

We need to point Sugar at an X server. One easy (but insecure) way to do this is to make a nested X server like so, outside the chroot:

Xephyr -ac :1 -screen 800x600x24 # 1024x768x24

See the talk page for more secure alternatives.

Running Sugar

Then, inside the chroot, you can happily run sugar as user 'sugar' with something like

sudo chroot $CHROOT /bin/bash -l
su sugar -
cd ~
ulimit -c unlimited
export DISPLAY=localhost:1
export DBUS_SESSION_BUS_ADDRESS=$(dbus-daemon --session --print-address --fork)
sugar

Then pull up the frame, switch to the home view, and launch some activities!

Cleaning Up

To correctly delete a chroot that you no longer need, kill all processes running in the chroot, and

sudo killall -u sugar
export CHROOT=/path/to/my/chroot  # important!
umount $CHROOT/var/run/dbus
umount $CHROOT/proc
umount $CHROOT/dev/pts
umount $CHROOT/tmp
rm -rf $CHROOT