Difference between revisions of "Development Team/Chroot"

Revision as of 11:04, 23 May 2009

Sugar ought to be easy to run from chroots. For a variety of silly reasons, this isn't yet the case, but it might be soon. Ping Michael with questions.

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 sid chroot

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

export CHROOT=`pwd`/sid-root
sudo debootstrap --arch i386 sid $CHROOT http://debian.lcs.mit.edu/debian
sudo chroot $CHROOT /bin/bash -l
# and some of the following:
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

Fedora rawhide chroot

With mock, it would be more like:

mock -r fedora-devel-i386 --init
mock -r fedora-devel-i386 --shell

Sugar Installation

jaunty chroot

sed -ie "s/main/main universe/" /etc/apt/sources.list
apt-get update
apt-get install sugar sugar-activities
# install your development tools here

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

See the talk page for more secure alternatives.

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.)

User Account

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

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

 su sugar -
 export DISPLAY=:1
 export DBUS_SESSION_BUS_ADDRESS=$(dbus-daemon --session --print-address --fork)
 sugar

@@ Line 64: / Line 64: @@
 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, run something like this ''both'' inside and outside the chroot:
+Consequently, ''as root'', run something like this ''both'' inside and outside the chroot:
    groupadd -g 64002 sugar