NetBoot server

NetBoot using PXE and TFTP.

This will boot using an official installation image.

Reminder:

• NetBoot requires a DHCP server
• TFTP is NOT secure at all. You should only use it into your internal network !!

=> Don't forget to adjust your firewall rules

Installation

Trivial FTP (TFTP) client

apt-get install tftp-hpa

Trivial FTP (TFTP) server

apt-get install tftpd-hpa

SysLinux [netboot utilities]

apt-get install syslinux mtools initramfs-tools

Syslinux contains some starter files you can use for your netboot clients.

Configuration

TFTP configuration

vim /etc/default/tftpd-hpa

The TFTP server files, = the files that will be used by the TFTP clients, are in the "TFTP_DIRECTORY" instruction.

By default tftpd-hpa uses /var/lib/tftpboot

!! You should not change the default user or port number if you plan to use NetBoot !!

service tftpd-hpa restart

Firewall configuration

Adjust your firewall script and add the following rules:

IPTABLES=`which iptables`
LAN_ADDRESS="172.16.50.0/24"

$IPTABLES -A INPUT -p udp -s $LAN_ADDRESS --dport 69 -j ACCEPT

Test the server

1. Create a file on the server

vim /var/lib/tftpboot/hello.txt

2. Connect to the server

Install TFTP client:

apt-get install tftp-hpa

Connect to the server and get file:

tftp 192.168.1.156
get hello.txt
quit

Check the received file:

cat hello.txt

Setup NetBoot files

Use an Ubuntu ISO image as NetBoot

Download the latest Ubuntu netboot image for the target architecture(s) from: http://cdimage.ubuntu.com/netboot/

You have to take the netboot.tar.gz archive.

cd /var/lib/tftpboot/
mkdir amd64
cd amd64
wget http://archive.ubuntu.com/ubuntu/dists/trusty/main/installer-amd64/current/images/netboot/netboot.tar.gz
tar -xzvf netboot.tar.gz
rm netboot.tar.gz

Register files in DHCP server

Edit your DHCP server configuration:

vim /etc/dhcp/dhcpd.conf

Adjust it like that:

        #### NETBOOT settings 
        # PXE file to serve.
        #   >> elilo.efi   => for ia64 clients; 
        #   >> pxelinux.0  => for x86
        # These files should be at the root of your TFTP server
        # Note: The file name can be add in the "host" section too. Then, the "host" will override the current setting
        filename "amd64/pxelinux.0";
        # set the server that serve this NETBOOT file
        next-server 172.16.50.2;
        # Ensure that the new client (the one booting) is not stealing someone else IP @
        ping-check = 1;

Mind the "amd64/" in the filename section.

You can always override that setting later on for each host.

Restart the DHCP server

service isc-dhcp-server restart

Custom NetBoot configuration

Basic configuration

You can setup your own netboot configuration.

To do so, you can re-use one of the syslinux templates:

# Create folders
mkdir /var/lib/tftpboot/custom
mkdir /var/lib/tftpboot/custom/pxelinux.cfg

# Create configuration files
cp /usr/lib/syslinux/pxelinux.0 /var/lib/tftpboot/custom

The pxelinux.cfg folder is mandatory. Inside you can provide:

• configuration for a specific IP @ or hostname
• configuration for a group
• default configuration (required)

Create the default configuration file:

vim /var/lib/tftpboot/custom/pxelinux.cfg/default

Put the following:

# Ubuntu 14.04
LABEL TRUSTY
    kernel trusty/vmlinuz
    initrd trusty/initrd.img

# Prompt user for selection
PROMPT 0

TIMEOUT 30

• Each LABEL is a specific configuration that will displayed on the NetBoot menu.
• PROMPT 1 = enable user prompt so you can choose the configuration
• TIMEOUT 30 = timeout (in seconds) before the default option is choosen

Note that I used a reference to "trusty/", that's a folder I need to create later on.

Create boot files

mkdir /var/lib/tftpboot/custom/trusty
# Copy current boot files
cp /boot/vmlinuz-3.2.0-4-amd64 /var/lib/tftpboot/custom/trusty/
cp /boot/initrd.img-3.2.0-4-amd64 /var/lib/tftpboot/custom/trusty/
# Create symlinks
ln -s /var/lib/tftpboot/custom/trusty/vmlinuz-3.2.0-4-amd64 /var/lib/tftpboot/custom/trusty/vmlinuz
ln -s /var/lib/tftpboot/custom/trusty/initrd.img-3.2.0-4-amd64 /var/lib/tftpboot/custom/trusty/initrd.img

TFTP management

Just use the "service" command:

service tftpd-hpa {status|restart|start|stop}

Next step: Diskless server / workstation