Virtual Infrastructure: kvm , uvb + libvirt

1. Virtual Infrastructure:kvm, uvb + libvirt Bryan McLellan http://loftninjas.org btm@loftninjas.org Senior Systems Administrator Widemile

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

3. 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 What I got for “free”

4. Problems • Lack of Homogeneity • Monkey configuration sucks • Documentation offensive http://www.flickr.com/photos/annebuzz/2666654754/

5. What I did • Lack of Homogeneity • debianpxe 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

6. We can always do better http://www.flickr.com/photos/jpasden/67513019/

7. 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

8. 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.

9. 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)

10. virsh

11. virt-manager

12. 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 • --addpkgopenssh-server • -d /srv/kvm/#{hostname} • --domain #{domain} • --hostname #{hostname} • --mem #{memory} • --mirror http://ubuntu.widemile.com/ubuntu • --libvirt qemu:///system • --bridge #{eth0}

13. 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 • --addpkgopenssh-server • -d /srv/kvm/#{hostname} • --domain #{domain} • --hostname #{hostname} • --mem #{memory} • --mirror http://ubuntu.widemile.com/ubuntu • --libvirt qemu:///system • --bridge #{eth0} Not a lot of enterprise features yet Bridging vs NAT Root password / creates user

14. 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; }

15. 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"]; }

16. 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/modprobedm_mod", onlyif => "/usr/bin/test `/bin/lsmod | grep -c '^dm_mod'` -lt 1", } realize Group["libvirtd"] } } }

17. http://loftninjas.org