Virtual Infrastructure: kvm, uvb + libvirt Bryan McLellan Senior Systems Administrator Widemile

Widemile is awesome I work there, and thus the world is a better place for all of humanity.

What I got for “free” Identical Blades Running non identical Debian installs (etch/sid, i386/amd64) Running different versions of vmware-server OS, software, installed by hand Configure using notes in an outlook public folder Host database tracked with DNS vm04-something.test.widemile.com

Problems Lack of Homogeneity Monkey configuration sucks Documentation offensive

What I did Lack of Homogeneity – debian pxe install with preseeds Monkey configuration sucks – puppify (configuration management) – capistrano (ruby scripting over ssh) – iclassify (node classification) Documentation offensive – Configuration management is self documenting – Wikify the notes

We can always do better

What upset me (nobody else cares) PXE installs take soooooo long Backporting too many packages to debian Interacting with VMware programmatically too much work. VMware UIs cost $$ Dreams: cpu/ram hotplug, live migration

How I Learned to Stop Worrying and Love the Bomb PXE installs take soooooo long – deb-bootstrap with ubuntu-vm-builder (2.5min) Backporting too many packages to debian – switch to Ubuntu! Interacting with VMware programmatically too much work. – libvirt is much easier and cleaner VMware UIs cost $$ – Libvirt is free Dreams: cpu/ram hotplug, live migration – Word on the street is that kvm + libvirt support these – I don’t think they’re there yet though.

libvirt – virtualization API Started at Redhat ‘s Emerging Technology Group Was Xen focused, but Redhat recently bought Qumranet, makers of KVM Ubuntu/Canonical picked KVM as virtualization platform of choice libvirt doesn’t really support all that Provides CLI management (virsh) Provides GUI management (virt-manager)

virsh

virt-manager

ubuntu-vm-builder Bash script wrapper for deb-bootstrap + qemu apt-get install ubuntu-vm-builder capistrano script: vmware: 102 lines uvb: 12 lines ubuntu-vm-builder kvm hardy --addpkg openssh-server -d /srv/kvm/#{hostname} --domain #{domain} --hostname #{hostname} --mem #{memory} --mirror --libvirt qemu:///system --bridge #{eth0}

ubuntu-vm-builder Bash script wrapper for deb-bootstrap + qemu apt-get install ubuntu-vm-builder capistrano script: vmware: 102 lines uvb: 12 lines ubuntu-vm-builder kvm hardy --addpkg openssh-server -d /srv/kvm/#{hostname} --domain #{domain} --hostname #{hostname} --mem #{memory} --mirror --libvirt qemu:///system --bridge #{eth0} Not a lot of enterprise features yet Bridging vs NAT Root password / creates user Not a lot of enterprise features yet Bridging vs NAT Root password / creates user

kvm The cool hypervisor on the block (ubuntu, redhat) Kernel modifications are mainlined (unlike xen) Super fast / lightweight (feel the wind in your hair) Growing fast class kvm { case $lsbdistid { "Ubuntu": { # Only Ubuntu releases are new enough for this package { "kvm": ensure => present; "libvirt-bin": ensure => present; "ubuntu-vm-builder": ensure => latest; }

file { "/srv/kvm": ensure => directory, group => admins, mode => 0775, } # Permissions required for remote access # Puppet doesn't support managing the libvirtd group members through the group type file { "/var/run/libvirt/libvirt-sock": group => admins, require => Service["libvirt-bin"]; "/var/run/libvirt/libvirt-sock-ro": group => admins, require => Service["libvirt-bin"]; }

service { "libvirt-bin": ensure => running, hasstatus => true, require => Package["libvirt-bin"], } # required by u-v-b exec { "devmapper-autoload": command => "/bin/echo dm_mod >> /etc/modules", onlyif => "/usr/bin/test `grep -c '^dm_mod' /etc/modules` -lt 1", } exec { "devmapper-load": command => "/sbin/modprobe dm_mod", onlyif => "/usr/bin/test `/bin/lsmod | grep -c '^dm_mod'` -lt 1", } realize Group["libvirtd"] }