Gentoo template creation

This page is about making a template cache for OpenVZ VE from Gentoo linux. The method is basically the same as described in article Slackware template creation.

Downloading stage3

We shall do the template from stage3 file. OpenVZ OS template should be an archive of root of the working system, but without the kernel and some files. You can download stage3 from the nearest mirror here: http://www.gentoo.org/main/en/mirrors.xml.

Create directory for the new VPS and unarchive stage3 there:

mkdir /vz/private/777
tar -xjf /root/stage3-i686-2006.0.tar.bz2 -C /vz/private/777

Creating VE config

Now you need to create the configuration file for the VE, 777.conf:

vzctl set 777 --applyconfig vps.basic --save

Editing config

Add to the /etc/vz/conf/777.conf:

DISTRIBUTION="gentoo"
OSTEMPLATE="gentoo"

Make /etc/mtab a symlink to /proc/mounts.

ln -s /proc/mounts /vz/private/777/etc/mtab

Editing /etc/fstab

echo "proc /proc proc defaults 0 0" > /vz/private/777/etc/fstab

We need only /proc to mounted at the boot time.

Editing inittab

Edit /etc/inittab, put a hashmark (#) before the lines containing:

c?:1235:respawn:/sbin/agetty 38400 tty? linux

This prevents from starting getty and login.

Editing /etc/shadow

Edit /vz/private/777/etc/shadow, change root's password in the first line to an exclamation mark (!):

root:!:10071:0:::::

This will disable the root login until the password changed with vzctl set 777 --userpasswd root:password.

Editing /etc/init.d/checkroot

We have to clean this script and make them dummy, because we don't need mount or check root.

cat > /etc/init.d/checkroot
#!/sbin/runscript
depend()
{
}
start()
{
}
end()
{
}

Editing /sbin/rc

Comment line number 141:

try mount -n ${mntcmd:--t sysfs sysfs /sys}

This prevents from attepting to mount /sys.

Setting up udev

Delete /lib/udev-state/devices.tar.bz2 and create some device nodes needed to enter VPS:

rm /lib/udev-state/devices.tar.bz2
mknod /lib/udev/devices/ttyp0 c 3 0
mknod /lib/udev/devices/ptyp0 c 2 0
mknod /lib/udev/devices/ptmx c 5 2

Testing

vzctl start 777
vzctl enter 777

You can check running services.

rc-status -a

All services in boot and default runlevels must be started. If everything all right, stop it

vzctl stop 777

Making distfiles и portage of the host system available in VPS.

To install software into VPS with portage you should mount /usr/portage into VPS with "bind" option. Do this after VPS starts:

mkdir /vz/root/777/usr/portage
mount -o bind /usr/portage /vz/root/777/usr/portage

If your /usr/portage/distfiles placed on the other partition do:

mount -o bind /usr/portage/distfiles /vz/root/777/usr/portage/distfiles

Now, to install package into VPS you just need enter there by chroot or vzctl enter and

emerge package_name

while you have all needed files in the /usr/portage/distfiles of host system.

For security reasons hold this directories mounted only while you are installing software into VPS.

Creating the cache file

cd /vz/private/777/
tar czf /vz/template/cache/gentoo.tar.gz *

Testing the new cache file

vzctl create 800 --ostemplate gentoo --ipadd 192.168.0.10 --hostname testvps

If created successfully, try to start it:

vzctl start 800

If it started, and you can ssh in, congratulations, you've got a working Gentoo template!