Pyromania: /* Final Cleanup */

2014-05-11T05:31:13Z

Final Cleanup

← Older revision		Revision as of 21:31, 10 May 2014
Line 220:		Line 220:

	====Final Cleanup====		====Final Cleanup====

			Set a hostname.

	Remove /etc/udev/rules.d/70-persistent-net.rules so that network comes up clean when the image is booted for the first time.		Remove /etc/udev/rules.d/70-persistent-net.rules so that network comes up clean when the image is booted for the first time.

	Remove SSH host keys so that new ones get generated on first boot.		Remove SSH host keys so that new ones get generated on first boot.

			Set a root password.

	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
			echo 'saucy' > /etc/hostname
	rm /etc/udev/rules.d/70-persistent-net.rules		rm /etc/udev/rules.d/70-persistent-net.rules
	rm /etc/ssh/ssh_host_*		rm /etc/ssh/ssh_host_*
			passwd root
	</syntaxhighlight>		</syntaxhighlight>

Pyromania: /* Ubuntu 13.10 */

2014-05-11T05:29:52Z

Ubuntu 13.10

@@ Line 96: / Line 96: @@
 auto eth0
 iface eth0 inet dhcp
 </syntaxhighlight>

Pyromania at 00:33, 10 May 2014

2014-05-10T00:33:52Z

← Older revision		Revision as of 16:33, 9 May 2014
Line 1:		Line 1:
			===Ubuntu 13.10===

	Start this process on a existing Ubuntu system. Does not have to be a 13.10 system. You will need to have debootstrap installed and may need to update debootstrap so it has the correct script for 13.10.		Start this process on a existing Ubuntu system. Does not have to be a 13.10 system. You will need to have debootstrap installed and may need to update debootstrap so it has the correct script for 13.10.

Pyromania: Created page with "Start this process on a existing Ubuntu system. Does not have to be a 13.10 system. You will need to have debootstrap installed and may need to update debootstrap so it has th..."

2014-05-10T00:32:38Z

Created page with "Start this process on a existing Ubuntu system. Does not have to be a 13.10 system. You will need to have debootstrap installed and may need to update debootstrap so it has th..."

New page

Start this process on a existing Ubuntu system. Does not have to be a 13.10 system. You will need to have debootstrap installed and may need to update debootstrap so it has the correct script for 13.10.

Create a empty image file and format it with ext3.

dd if=/dev/zero of=ubuntu_saucy.img bs=1M count=1 seek=1024
mkfs.ext3 ubuntu_saucy.img

Create a directory to mount the image on. Using '/mnt/img' for this example.

mkdir /mnt/img
mount -oloop ubuntu_saucy.img /mnt/img

Start the debootstrap process.

debootstrap saucy /mnt/img/

Once that completes, copy your existing /etc/apt/sources.list to the new image so we can run updates.

cp /etc/apt/sources.list /mnt/img/etc/apt/

Mount the necessary system files so that we can enter the new root filesystem with chroot.

mount --bind /dev /mnt/img/dev
mount --bind /dev/pts /mnt/img/dev/pts
mount -t proc proc /mnt/img/proc
mount -t sysfs sys /mnt/img/sys
chroot /mnt/img

Run updates and install a language pack.

apt-get update
apt-get install language-pack-en-base
apt-get upgrade

Configure the system timezone.

dpkg-reconfigure tzdata

Install the kernel image, SSH server and the full version of vim

apt-get install linux-image
apt-get install openssh-server
apt-get install vim

To use the Xen console 'xm console (domU)' you need to setup a tty on /dev/hvc0. Create the file '/etc/init/hvc0.conf' with this content.

<syntaxhighlight lang="bash">
# This service maintains a getty on hvc0 from the point the system is
# started until it is shut down again.

start on stopped rc RUNLEVEL=[2345] and (
not-container or
container CONTAINER=lxc or
container CONTAINER=lxc-libvirt)

stop on runlevel [!2345]

respawn
exec /sbin/getty -8 38400 hvc0
</syntaxhighlight>

The default udev rules for 13.10 ignore Xen generated MAC addresses so you won't get a '/etc/udev/rules.d/70-persistent-net.rules' This causes your network interfaces not to come up.

Edit '/lib/udev/rules.d/75-persistent-net-generator.rules' and comment these lines. Here's the changes in patch/diff format.

<syntaxhighlight lang="diff">
@@ -21,7 +21,7 @@ KERNEL!="eth*|ath*|wlan*[0-9]|msh*|ra*|s
GOTO="persistent_net_generator_end"

# ignore Xen virtual interfaces
-SUBSYSTEMS=="xen", GOTO="persistent_net_generator_end"
+#SUBSYSTEMS=="xen", GOTO="persistent_net_generator_end"

# ignore UML virtual interfaces
DRIVERS=="uml-netdev", GOTO="persistent_net_generator_end"
@@ -75,7 +75,7 @@ ENV{MATCHADDR}=="00:0c:29:*|00:50:56:*|0
ENV{MATCHADDR}=="00:15:5d:*", ENV{MATCHADDR}=""
ENV{MATCHADDR}=="52:54:00:*|54:52:00:*", ENV{MATCHADDR}=""
ENV{MATCHADDR}=="08:00:27:*", ENV{MATCHADDR}=""
-ENV{MATCHADDR}=="00:16:3e:*", ENV{MATCHADDR}=""
+#ENV{MATCHADDR}=="00:16:3e:*", ENV{MATCHADDR}=""

# ignore Windows Azure Hyper-V virtual interfaces
ENV{MATCHADDR}=="00:03:ff:*", ENV{MATCHADDR}=""
</syntaxhighlight>

Configure your '/etc/network/interfaces' for DHCP

<syntaxhighlight lang="bash">
# interfaces(5) file used by ifup(8) and ifdown(8)
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto eth0
iface eth0 inet dhcp
</syntaxhighlight>

Configure a basic fstab

<syntaxhighlight lang="bash">
# Begin /etc/fstab
# <file system> <mount-point> <type> <options> <dump> <pass>
/dev/sda1 / ext3 defaults,errors=remount-ro 0 0
proc /proc proc defaults 0 0

# End /etc/fstab
</syntaxhighlight>

====SSH host keys fix====

Since this image will get cloned and used to create new virtual machines we don't want to re-use the same keys for every virtual machine. Ubuntu won't regenerate SSH host keys if you delete them from /etc/ssh. So we need a script to check the host keys and regenerate them if needed.

Create /lib/init/ssh_gen_key and paste this in,

<syntaxhighlight lang="bash">
#!/bin/sh

# Some variables to make things more readable
KEYGEN=/usr/bin/ssh-keygen
RSA1_KEY=/etc/ssh/ssh_host_key
RSA_KEY=/etc/ssh/ssh_host_rsa_key
DSA_KEY=/etc/ssh/ssh_host_dsa_key
ECDSA_KEY=/etc/ssh/ssh_host_ecdsa_key

do_rsa_keygen() {
if [ ! -s $RSA_KEY ]; then
echo -n "Generating SSH2 RSA host key: "
rm -f $RSA_KEY
if test ! -f $RSA_KEY && $KEYGEN -q -t rsa -f $RSA_KEY -C '' -N '' >/dev/null; then
chmod 600 $RSA_KEY
chmod 644 $RSA_KEY.pub
echo "OK"
else
echo "FAIL"
exit 1
fi
fi
}

do_dsa_keygen() {
if [ ! -s $DSA_KEY ]; then
echo -n "Generating SSH2 DSA host key: "
rm -f $DSA_KEY
if test ! -f $DSA_KEY && $KEYGEN -q -t dsa -f $DSA_KEY -C '' -N '' >/dev/null; then
chmod 600 $DSA_KEY
chmod 644 $DSA_KEY.pub
echo "OK"
else
echo "FAIL"
exit 1
fi
fi
}

do_ecdsa_keygen() {
if [ ! -s $ECDSA_KEY ]; then
echo -n "Generating SSH2 ECDSA host key: "
rm -f $ECDSA_KEY
if test ! -f $ECDSA_KEY && $KEYGEN -q -t ecdsa -f $ECDSA_KEY -C '' -N '' >/dev/null; then
chmod 600 $ECDSA_KEY
chmod 644 $ECDSA_KEY.pub
echo "OK"
else
echo "FAIL"
exit 1
fi
fi
}

do_rsa_keygen
do_dsa_keygen
do_ecdsa_keygen
</syntaxhighlight>

chmod 755 /lib/init/ssh_gen_keys

Edit /etc/init/ssh.conf

<syntaxhighlight lang="bash">
@@ -20,6 +20,7 @@ pre-start script
test -c /dev/null || { stop; exit 0; }

mkdir -p -m0755 /var/run/sshd
+ /lib/init/ssh_gen_keys
end script

# if you used to set SSHD_OPTS in /etc/default/ssh, you can change the
</syntaxhighlight>

====Firewall====

<syntaxhighlight lang="bash">
apt-get install iptables
apt-get install ufw

ufw allow OpenSSH
ufw enable
</syntaxhighlight>

====Final Cleanup====

Remove /etc/udev/rules.d/70-persistent-net.rules so that network comes up clean when the image is booted for the first time.

Remove SSH host keys so that new ones get generated on first boot.

<syntaxhighlight lang="bash">
rm /etc/udev/rules.d/70-persistent-net.rules
rm /etc/ssh/ssh_host_*
</syntaxhighlight>

Linux/Xen/DomU/Ubuntu/Ubuntu 13.10 - Revision history

Pyromania: /* Final Cleanup */

Pyromania: /* Ubuntu 13.10 */

Pyromania at 00:33, 10 May 2014

Pyromania: Created page with "Start this process on a existing Ubuntu system. Does not have to be a 13.10 system. You will need to have debootstrap installed and may need to update debootstrap so it has th..."