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Script to create a user-mode linux machine using interactive questions
#!/bin/sh
### functions
f() { echo "Failed."; exit; }
setup_net()
{
echo "Configuring network"
while :; do
echo -n "IP address of the UML machine (e.g. 192.168.0.100) > "
read nw_ip
if [ "x$nw_ip" != "x" ]; then
break
fi
done
while :; do
echo -n "Network (e.g. 192.168.0.0) > "
read nw_network
if [ "x$nw_network" != "x" ]; then
break
fi
done
while :; do
echo -n "Broadcast address (e.g. 192.168.0.255) > "
read nw_bcast
if [ "x$nw_bcast" != "x" ]; then
break
fi
done
while :; do
echo -n "Netmask (e.g. 255.255.255.0) > "
read nw_netmask
if [ "x$nw_netmask" != "x" ]; then
break
fi
done
while :; do
echo -n "Your internet gateway (e.g. 192.168.0.1) > "
read nw_gw
if [ "x$nw_gw" != "x" ]; then
break
fi
done
while :; do
echo -n "Host interface (e.g. tap1) > "
read nw_if
if [ "x$nw_if" != "x" ]; then
break
fi
done
echo ""
echo "You entered:"
echo " IP address: $nw_ip"
echo " Network: $nw_network"
echo " Broadcast address: $nw_bcast"
echo " Netmask: $nw_netmask"
echo " Gateway: $nw_gw"
echo " Host interface: $nw_if"
while :; do
echo -n "Is this correct? [y/n]: "
read nw_ok
case "$nw_ok" in
y | yes)
break
;;
n | no)
setup_net
return
break
;;
*)
echo "Please enter 'y' or 'n'"
esac
done
}
### our script begins here
if [ "`id -u`" != "0" ]; then
echo "I won't run as user. I need root."
exit 1
fi
if [ "x$1" = "x" ]; then
echo "Enter the name of the UML machine or press CTRL+C to abort:"
echo -n "> "
read name
fi
if [ "x$name" = "x" ]; then
echo "Aborting."
exit 1
fi
echo
echo ==============================
echo Creating file system
echo ==============================
echo
if [ "x$1" = "x" ]; then
echo "Enter the size of your root partition in MB"
echo -n "> "
read size
fi
if [ "x$size" = "x" ]; then
echo "Aborting."
exit 1
fi
mkdir $name || f
# print this so the user does not think that the script is hanging
echo dd if=/dev/zero of=$name/root_fs count=$size bs=1M
dd if=/dev/zero of=$name/root_fs count=$size bs=1M || f
/sbin/mke2fs -F $name/root_fs || f
mkdir $name/install || f
mount -o loop $name/root_fs $name/install || f
echo
echo ==============================
echo Installing the base system
echo ==============================
echo
debootstrap wheezy $name/install http://ftp.us.debian.org/debian || f
echo
echo ==============================
echo Configuring the base system
echo ==============================
echo
echo '# /etc/fstab: static file system information.
#
# <file system> <mount point> <type> <options> <dump> <pass>
/dev/ubd0 / ext2 defaults 0 0
proc /proc proc defaults 0 0' \
> $name/install/etc/fstab
echo '# /etc/inittab: init(8) configuration.
# $Id: inittab,v 1.91 2002/01/25 13:35:21 miquels Exp $
# The default runlevel.
id:2:initdefault:
# Boot-time system configuration/initialization script.
# This is run first except when booting in emergency (-b) mode.
si::sysinit:/etc/init.d/rcS
# What to do in single-user mode.
~:S:wait:/sbin/sulogin
# /etc/init.d executes the S and K scripts upon change
# of runlevel.
#
# Runlevel 0 is halt.
# Runlevel 1 is single-user.
# Runlevels 2-5 are multi-user.
# Runlevel 6 is reboot.
l0:0:wait:/etc/init.d/rc 0
l1:1:wait:/etc/init.d/rc 1
l2:2:wait:/etc/init.d/rc 2
l3:3:wait:/etc/init.d/rc 3
l4:4:wait:/etc/init.d/rc 4
l5:5:wait:/etc/init.d/rc 5
l6:6:wait:/etc/init.d/rc 6
# Normally not reached, but fallthrough in case of emergency.
z6:6:respawn:/sbin/sulogin
# What to do when CTRL-ALT-DEL is pressed.
ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now
# Action on special keypress (ALT-UpArrow).
#kb::kbrequest:/bin/echo "Keyboard Request--edit /etc/inittab to let this work."
# What to do when the power fails/returns.
pf::powerwait:/etc/init.d/powerfail start
pn::powerfailnow:/etc/init.d/powerfail now
po::powerokwait:/etc/init.d/powerfail stop
# /sbin/getty invocations for the runlevels.
#
# The "id" field MUST be the same as the last
# characters of the device (after "tty").
#
# Format:
# <id>:<runlevels>:<action>:<process>
#
# Note that on most Debian systems tty7 is used by the X Window System,
# so if you want to add more getty'\''s go ahead but skip tty7 if you run X.
#
0:1235:respawn:/sbin/getty 38400 console linux
#1:2345:respawn:/sbin/getty 38400 tty1
#2:23:respawn:/sbin/getty 38400 tty2
#3:23:respawn:/sbin/getty 38400 tty3
#4:23:respawn:/sbin/getty 38400 tty4
#5:23:respawn:/sbin/getty 38400 tty5
#6:23:respawn:/sbin/getty 38400 tty6
# Example how to put a getty on a serial line (for a terminal)
#
#T0:23:respawn:/sbin/getty -L ttyS0 9600 vt100
#T1:23:respawn:/sbin/getty -L ttyS1 9600 vt100
# Example how to put a getty on a modem line.
#
#T3:23:respawn:/sbin/mgetty -x0 -s 57600 ttyS3' > $name/install/etc/inittab
echo $name > $name/install/etc/hostname
# set up apt
cp /etc/apt/sources.list $name/install/etc/apt/sources.list || f
# install SSH
while :; do
echo -n "Do you want to install SSH? [y/n]: "
read nw_config
case "$nw_config" in
y | yes)
chroot $name/install apt-get -y update || f
chroot $name/install apt-get -y install ssh || f
break
;;
n | no)
break
;;
*)
echo "Please enter 'y' or 'n'"
esac
done
# network
while :; do
echo -n "Do you want to configure the network? [y/n]: "
read nw_config
case "$nw_config" in
y | yes)
nw_config=1
break
;;
n | no)
nw_config=0
break
;;
*)
echo "Please enter 'y' or 'n'"
esac
done
if [ "$nw_config" = "1" ]; then
setup_net
echo '# Used by ifup(8) and ifdown(8). See the interfaces(5) manpage or
# /usr/share/doc/ifupdown/examples for more information.
auto lo
iface lo inet loopback
# eth0
auto eth0
iface eth0 inet static
address '$nw_ip'
netmask '$nw_netmask'
network '$nw_network'
broadcast '$nw_bcast'
gateway '$nw_gw > $name/install/etc/network/interfaces
fi
echo
echo ==============================
echo Create root password
echo ==============================
echo
chroot $name/install su - root -c "usermod -p `mkpasswd` root"
# clean up
umount $name/install
rmdir $name/install
echo
echo ==============================
echo Creating start script
echo ==============================
echo
while :; do
echo -n "Enter the amount of memory for the UML machine in MB: "
read mem
test $mem && break
done
if [ "$nw_config" = "1" ]; then
echo '#!/bin/sh
MEMORY="'$mem'M"
HOST_IFACE="'$nw_if'"
linux mem=$MEMORY eth0=tuntap,$HOST_IFACE' > $name/run
else
echo '#!/bin/sh
MEMORY="'$mem'M"
linux mem=$MEMORY' > $name/run
fi
chmod +x $name/run
echo
echo ==============================
echo Finished
echo ==============================
echo
echo To launch UML, type:
echo cd $name
echo ./run
echo
echo Have a lot of fun!
echo
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