custom live media spinning

Custom Live Media Spinning

Jon Cowie, [email protected]

@jonlives

Thursday, 11 July 13

mailto:[email protected]

mailto:[email protected]

1.5 billion page views$117 million of goods sold

950 thousand users

(in december ‘12)


~800 physical hosts~300 kvm & lxc VMs

CentOS 5 & 6


RacktablesCobbler

Chef


Old Host Build Process

Configure StorageConfigureSwitchports

Configure DNSConfigure Cobbler

Power on HostProfit!

Rack Server Configure ILO


New Host Build Process





Gabriel


New Host Build Process





Sledgehammer


Sledgehammer

Runs before OS InstallConfigures ILO

Configures RAID & GPT


Live CD!

Memory residentNetwork bootable*Easily customisable


Sledgehammer Live CD

Minimal installNetwork, disk tools

Ruby & GemsSledgehammer “Runner”


Sledgehammer Runner

Mount NFSDownload config

Download payload RPMRun payload


Sledgehammer Payload

Configure ILO Set up RAID

Configure GPT Burn-in tests

Update Racktables


So how does it work?


LiveCD Primer

-isolinux-initrd0.img-vmlinuz0

-LiveOS-squashfs.img-ext3fs.img


LiveCD Primer

Load kernel and ramdiskMount ro / fs

Create rw overlayRun init


First modification!

Overlay is fixed size.Copy entire FS to tmpfs

Mount rw / FS


Second modification!

Custom payloadMust run automatically...


/etc/init/start-ttys.conf

...env ACTIVE_CONSOLES=/dev/tty[1-‐6]...for tty in $(echo $ACTIVE_CONSOLES) ; do ... initctl start tty TTY=$ttydone...


/etc/init/start-ttys.conf...env ACTIVE_CONSOLES=/dev/tty[1-‐6]...for tty in $(echo $ACTIVE_CONSOLES) ; do ...

if [ \"\$tty\" == \"\/dev/tty1\" ] then initctl start centosdojo TTY=\$tty else initctl start tty TTY=\$tty fidone...


/etc/init/centosdojo.conf

stop on runlevel [012456]exec /usr/bin/openvt -‐c 1 -‐w -‐f -‐-‐ /opt/centosdojo/runner.rb


So how do I build it?


http://tiny.cc/dojo2013




custom live media spinning

Technology

env active consoles dev tty

echo active consoles

thursday

img

conf

tty

init start

ttys