This SaltConf14 talk by Matthew Williams of Flowroute shows the power of Salt Virt and Runner for creating and managing VMs and Linux containers. A demonstration of the Salt lxc module shows the simplicity with which containers and VMs can be created and configured.

2. Salt Virt for Linux Containers and Virtualization Management

3. Matthew Williams
matthew@flowroute.com

4. • Enterprise Class VoIP Provider!
• Manage about 100 minions… and growing!
• Adopted Salt in 2013

5. Salt and Virtualization
• Two Unique Systems!
• virt: Virtualization via libvirt (e.g., KVM, VMware)!
• lxc: Linux Containers

6. virt

7. virt
• virt execution module!
• create, destroy, start, stop VMs!
• obtain information about VMs!
• virt runner!
• orchestrate deployment of VMs!
• pre-accept minion keys for VMs

8. Preparing the Host
• Host system with libvirt and python-libvirt installed!
• Network bridge configured (On Ubuntu libvirt-bin
package does this for you)!
• default nic profile in pillar
or minion config:
virt.nic:!
default:!
eth0:!
bridge: virbr0!
model: virtio

9. Preparing an Image
• A base VM image is needed.!
• May be built with vmbuilder:
vmbuilder kvm ubuntu --suite precise --flavour virtual - !
--dest test_img --ppa saltstack --addpkg salt-minion
• Preinstall salt-minion if possible!
• Most cloud-ready images will also work

10. Creating VMs
salt-run virt.init test 1 256 salt://test_img.qcow nic=default
• selects the least loaded hyper (based on memory)!
• caches and clones the image!
• installs salt-minion (if needed)!
• configures the minion and pre signs its key!
• starts the VM

11. Managing VMs
salt-run virt.pause test!
salt-run virt.resume test
• pause and resume
• power off and restart
salt-run virt.force_off test!
salt-run virt.start test
salt-run virt.reset test

12. Managing VMs
salt-run virt.purge test
• delete forever

13. Documentation
http:/docs.saltstack.com/topics/tutorials/cloud_controller.html!
!
http://docs.saltstack.com/ref/runners/all/salt.runners.virt.html

14. lxc: Linux Containers

15. lxc
• lxc execution module!
• create, destroy, start, stop containers!
• obtain information about containers!
• lxc runner (develop branch only)!
• orchestrate deployment of containers!
• pre-accept minion keys for containers

16. Linux Containers
• Kernel containment features are utilized, including:!
• Namespaces (ipc, uts, mount, pid, network and user)!
• Chroots!
• cgroups!
• More like a virtual environment than a virtual machine
More Info: www.linuxcontainers.org

17. Preparing the Host
• Install the lxc package and ensure the service is running
lxc:!
pkg:!
- installed!
service:!
- running!
- require:!
- pkg: lxc

18. Preparing the Host
• configure lxc.nic and lxc.profile in
pillar (or minion config)
lxc.nic:!
default:!
eth0:!
link: lxcbr0!
type: veth!
!
lxc.profile:!
ubuntu:!
template: ubuntu!
backing: lvm!
vgname: lxc!
size: 1G

19. The LXC Runner
salt-run lxc.init name host=minion_id [cpuset=cgroups_cpuset]
[cpushare=cgroups_cpushare] [memory=cgroups_memory]
[nic=nic_profile] [profile=lxc_profile]
[nic_opts=nic_opts] [start=(true|false)]
[seed=(true|false)] [install=(true|false)]
[config=minion_config]

20. Creating a Container
salt-run lxc.init test host=host_minion !
profile=ubuntu memory=256
• Utilizes the ubuntu lxc template (many are available)!
- Pulls an ubuntu image, if needed, and caches it!
• Installs salt-minion and pre-seeds config and keys!
• Starts the container

21. Managing Containers
salt-run lxc.freeze test!
salt-run lxc.unfreeze test
• freeze and unfreeze
• power off and restart
salt-run lxc.stop test!
salt-run lxc.start test

22. Managing Containers
salt-run lxc.purge test
• delete forever

23. Documentation
http://docs.saltstack.com/ref/runners/all/salt.runners.lxc.html!
!
http://docs.saltstack.com/ref/modules/all/salt.modules.lxc.html

24. We’re Hiring
flowroute.com/jobs

25. Questions?
irc:mgw
matthew@flowroute.com
www.github.com/mgwilliams