gentoo-pxe-builder

Purpose

The purpose of this PXE builder is to let you boot a machine from PXE and then automatically set it up so you can access it remotely using SSH.

Booting this PXE initramfs will display informations about the network interfaces available on the PXE host so that you don't need to type any sort of command to connect to it.

What it does for you

This automation script prepares a Gentoo kernel and initramfs suitable to boot from PXE:

• It bases itself from the latest minimal ISO available
• It will setup a root password and start the SSH daemon

It lets you take control of the PXE host easily:

• You can change the files/setup.start script to adjust your needs at boot and rebuild the whole PXE stack by simply re-runing the build.sh script
• Your SSH public key will already be present on the machine so you can connect without password to your PXE host

What will happen when I boot ?

• At first this will start your machine just like a simple livecd
• Then it will start waiting for connectivity and display the current IP of your network cards
• As soon as one gets an IP address, it will setup the root password and start the SSH daemon
• Finally, it will discover and display for you the real name of the network interfaces detected on the host based on udev deterministic naming

Usage

• Modify the files/setup.start to match any specific need other than those already prepared for you
• Then just execute the build.sh script and enjoy.

Prerequisites

• The cpio command from app-arch/cpio
• The gpg command from app-crypt/gnupg
• The mksquashfs command from sys-fs/squashfs-tools
• The sudo command from app-admin/sudo
• The xzcat command from app-arch/xz-utils
• Your current user must be a sudoer with the right to execute any command
• You must have imported the 'Gentoo Linux Release Engineering (Automated Weekly Release Key)' GPG public key in your keyring

Environment variables and defaults

The default SSH root password is gentoo-root. This is the list of accepted environment variables:

• ARCH : amd64
• MIRROR : http://distfiles.gentoo.org
• SSH_KEY_PATH : ~/.ssh/id_rsa.pub

PXE server basic setup

Setting up a PXE server is quite easy, just remember a few things:

• Suppose we want our PXE root to be located in /pxe/
• Install sys-boot/syslinux as it contains the necessary files:

$ sudo cp /usr/share/syslinux/ldlinux.c32 /pxe/
$ sudo cp /usr/share/syslinux/pxelinux.0 /pxe/

• Create the /pxe/pxelinux.cfg/ directory
• Create the default PXE boot file /pxe/pxelinux.cfg/default:

default Gentoo

label Gentoo
kernel /gentoo_pxe/gentoo
append initrd=/gentoo_pxe/gentoo.igz root=/dev/ram0 init=/linuxrc loop=/image.squashfs looptype=squashfs cdroot=1 real_root=/dev/sda