Xen Summit 2008 Tokyo 2008/11/21 paperboy&co. Gosuke Miyashita

Agenda About me Purpose of this talk What is libvirt libvirt Xen driver architecture libvirt sample codes with Perl/Python Related tools (Avahi and Func)

About me

Purpose of this talk

What is libvirt

libvirt Xen driver architecture

libvirt sample codes with Perl/Python

Related tools (Avahi and Func)

About me Gosuke Miyashita http://mizzy.org/ Technical manager at paperboy&co. Web hosting, blog, ec hosting and so on for indivisuals Thinking introduce virtualization technologies to our services

Gosuke Miyashita

http://mizzy.org/

Technical manager at paperboy&co.

Web hosting, blog, ec hosting and so on for indivisuals

Thinking introduce virtualization technologies to our services

Purpose of this talk I seek how to manage Xen domains on many host machines I need a simple and customizable tool It may be fast to develop my own tool libvirt is the one for developing my own Xen management tool Why python and perl? These languages may be used widly in system administration

I seek how to manage Xen domains on many host machines

I need a simple and customizable tool

It may be fast to develop my own tool

libvirt is the one for developing my own Xen management tool

Why python and perl?

These languages may be used widly in system administration

What is libvirt? The virtualization API A library intracts with virtualization systems Xen, QEMU, KVM, LXC and OpenVZ Language bindings C, Python, Perl, OCaml, Ruby, Java and C# Support multiple authentication methods SSH, TLS and X.509, SASL and Kerberos Avahi multicast DNS support

The virtualization API

A library intracts with virtualization systems

Xen, QEMU, KVM, LXC and OpenVZ

Language bindings

C, Python, Perl, OCaml, Ruby, Java and C#

Support multiple authentication methods

SSH, TLS and X.509, SASL and Kerberos

Avahi multicast DNS support

What can you do with libvirt? Get Dom0 info CPU model/threads/cores, memory size and so on List domains Get domain info id, uuid, name, xml description, os type and state Various domain operations create, shutdown, reboot, suspend, resume set/get max memory/memory size, get max vcpus Network, Storage operations (excluded in this talk) See http://libvirt.org/html/libvirt-libvirt.html

Get Dom0 info

CPU model/threads/cores, memory size and so on

List domains

Get domain info

id, uuid, name, xml description, os type and state

Various domain operations

create, shutdown, reboot, suspend, resume

set/get max memory/memory size, get max vcpus

Network, Storage operations (excluded in this talk)

See http://libvirt.org/html/libvirt-libvirt.html

libvirt Xen driver(local) xend xenstored xen hypervisor libvirt Perl Python OCaml Ruby Java C# C

libvirt Xen driver(remote) xend xenstored xen hypervisor libvirtd Perl Python OCaml Ruby Java C# C libvirt Over a network

Perl code example use Sys::Virt ; # connect to the remote host my $vmm = Sys::Virt->new( uri => "xen://remote_host/“ ); # get domains my @doms = $vmm->list_domains; # print state of each domains for my $dom ( @doms ) { printf " %s: %s
" , $dom->get_name, $dom->get_info->{ state }; }

use Sys::Virt ;

# connect to the remote host

my $vmm =

Sys::Virt->new( uri => "xen://remote_host/“ );

# get domains

my @doms = $vmm->list_domains;

# print state of each domains

for my $dom ( @doms ) {

printf " %s: %s
" ,

$dom->get_name, $dom->get_info->{ state };

}

Python code example import libvirt # connect to the remote host conn = libvirt.open(‘ xen://remote_host/’ ) # get domain ids ids = conn.listDomainsID() # print state of each domains for id in ids: vm = conn.lookupByID(id) print "%s: %s" % ( vm.name(), vm.info()[0] )

import libvirt

# connect to the remote host

conn = libvirt.open(‘ xen://remote_host/’ )

# get domain ids

ids = conn.listDomainsID()

# print state of each domains

for id in ids:

vm = conn.lookupByID(id)

print "%s: %s" % ( vm.name(), vm.info()[0] )

Avahi support libvirt is integrated with Avahi Ahahi is a one of mDNS implementation You can discover hosts with libvirtd running by mDNS client automatically

libvirt is integrated with Avahi

Ahahi is a one of mDNS implementation

You can discover hosts with libvirtd running by mDNS client automatically

Perl example with libvirt and avahi use Net::Bonjour ; use Sys::Virt ; # discover hosts with libvirtd running my $res = Net::Bonjour->new( 'libvirt' ); $res->discover; # access libvirtd on each host for my $host ( $res->entries ) { my $vmm = Sys::Virt->new( uri => ‘xen://’ . $host->address ); .... }

use Net::Bonjour ;

use Sys::Virt ;

# discover hosts with libvirtd running

my $res =

Net::Bonjour->new( 'libvirt' );

$res->discover;

# access libvirtd on each host

for my $host ( $res->entries ) {

my $vmm =

Sys::Virt->new( uri => ‘xen://’ . $host->address );

....

}

Func Fedora Unified Network Controller https://fedorahosted.org/func/ Sysadmin application framework made of Python A programming framework for “Exec some operations for multiple hosts” Many modules yum, user, service, command, smart, virt ... Virt module uses libvirt

Fedora Unified Network Controller

https://fedorahosted.org/func/

Sysadmin application framework made of Python

A programming framework for “Exec some operations for multiple hosts”

Many modules

yum, user, service, command, smart, virt ...

Virt module uses libvirt

Func virt module sample code import func.overlord.client as fc # call state method of virt module on all hosts results = fc.Client( "*" ).virt.state() # create domain if domain state is ‘shutdown’ for ( host, vms ) in results.iteritems(): if vms[0] == 'REMOTE_ERROR': continue for vm in vms: ( domain, state ) = vm.split( ' ' ) if state == 'shutdown' : fc.Client(host).virt.create(domain)

import func.overlord.client as fc

# call state method of virt module on all hosts

results = fc.Client( "*" ).virt.state()

# create domain if domain state is ‘shutdown’

for ( host, vms ) in results.iteritems():

if vms[0] == 'REMOTE_ERROR':

continue

for vm in vms:

( domain, state ) = vm.split( ' ' )

if state == 'shutdown' :

fc.Client(host).virt.create(domain)