grub2 Network Boot Infrastructure

Maintainer: jloeser@suse.de

Description

This project holds all necessary configurations and script files for grub2 network boot.

Network Boot Process

TFTP Boot root directory: /srv/tftpboot

DHCP configuration

Architecture	Binary(s)
x86_64-efi	grub2/shim-x86.efi > grub2/grub.efi
x86_64-legacy (pxe)	pxelinux.0 > grub2/grub.0
ppc64	grub2/grub.ppc64
ppc64le	grub2/grub.ppc64le

EFI uses currently shim-x86.efi to bootstrap the grub2 EFI binary.

On x86_64-legacy there is an grub2/grub1 issue! When booting the grub.pxe (grub2) via network, using local for chainloading grub1 from disk, the kernel/initrd gets loaded but does not start. Therefor, we load pxelinux.0 on non-EFI (=legacy) x86_64 machines and bootstrap grub2 in case of an Orthos setup/installation (label: network). Otherwise, the pxelinux.0 just boots from disk as usual (label: local).

Source order

#	Configuration file	Comment
1	grub2/grub.cfg	generic root configuration
2	grub2/00-config/<mac-address>	autogenerated; machine specific variables
(3)	grub2/<arch>/01-orthos-install/<hostname>	autogenerated, optional; sets grub2 default and timeout if triggered
(4)	grub2/<arch>/02-grub.cfg	optional; architecture specific variables
(5)	grub2/<arch>/90-custom/<hostname>	optional; add your machine specific configuration HERE
6	grub2/<arch>/99-*.cfg	arch specific template files for SLE, openSUSE, ...

Reset default after machine setup was triggered

Script: grub2/scripts/setup-reset.py

• use rcsetup-reset start|stop
• logfile: /var/log/grub2/reset
• required: /var/log/tftpd.log (see below)

Create machine specific stub:

Script: grub2/scripts/setup.py

• no manual interaction needed; triggered by Orthos

• Example:

  grub2/scripts/setup.py --arch x86_64 \ --mac 00:11:22:33:44:55 \ --fqdn foobar.suse.de \ --serial-console true \ --serial-line 1 \ --kernel-options "+noresume"

Remove machine specific grub2 default files (clean up for unclaimed files):

Script: grub2/scripts/setup-remove-deprecated-defaults.py

• remove files (3) if mtime is older than 4h
• cron job: /etc/cron.d/remove_deprecated_defaults (every hour)
• Example:

0 * * * * root python /srv/tftpboot/grub2/scripts/setup-remove-deprecated-defaults.py

Create tftpd.log file

• install TFTP server: zypper in tftp
• create empty log file: touch /var/log/tftpd.log
• change file permissions: chmod 644 /var/log/tftpd.log
• modify /etc/xinetd.d/tftp:

# default: off
# description: tftp service is provided primarily for booting or when a \
#       router need an upgrade. Most sites run this only on machines acting as
#       "boot servers".
service tftp
{
    disable         = no
    socket_type     = dgram
    protocol        = udp
    wait            = yes
    user            = root
    server          = /usr/sbin/in.tftpd
    server_args     =  -v -v -s /tftpboot
    flags           = IPv6 IPv4
}

• restart xinetd service: rcxinetd restart
• restart tftpd service: rctftp restart
• modify /etc/systemd/journald.conf (remove comments):

...
ForwardToSyslog=yes
MaxLevelSyslog=debug
...

• add rsyslog rule in /etc/rsyslog.conf:

...
# tftpd log
#
if      ($programname == 'in.tftpd') or \
        ($msg contains 'tftpd') \
then {
        -/var/log/tftpd.log
}
...