[Ovirt-devel] Dev setup for a home network

[David Lutterkort]

Since I am cheap (and hate fiddling with cables), I wanted an OVirt dev
setup that would fit more closely into how my home network is setup. In
particular,

      * the WUI appliance should be a VM that is on the main network,
        i.e. using a shared network interface
      * PXE boot my existing hardware as a OVirt managed node, without
        having to put them on a separate network

Like for most people, my home network is one segemnt on which I already
run DNS and DHCP. Here's what I had to do to get there:

(1) Download and install the OVirt WUI appliance following the
instructions on the website.

(2) Modify the libvirt XML for the appliance to put its first network
interface onto the bridge (let's call it eth0) used for shared
networking. For that, you need to

      * virsh dumpxml developer > /tmp/developer.xml
      * edit /tmp/developer.xml and change the first <interface> block
        to
        
        <interface type='bridge'>
            <mac address='52:54:00:22:83:50'/>
            <source bridge='eth0'/>
        </interface>
        
      * virsh define /tmp/developer.xml

(3) Enter the MAC address above, a fixed IP and hostname (let's call
that ovirt.home.net) into your existing DHCP server. If you use dnsmasq,
I'll attach the relevant bits to this mail. You should also enter IP and
hostname into /etc/hosts on your DHCP server. To play it safe, you also
want management.priv.ovirt.org to be an alias for ovirt.home.net; I
don't know how to do that with bind, but for dnsmasq, just add an alias
in /etc/hosts for ovirt.home.net, i.e. altogether you want to have a
line like
        172.31.0.129 ovirt.home.net management.priv.ovirt.org

(4) Start the WUI appliance with 'virsh start developer' and 'ssh -Y
root at ovirt.home.net'. The following all needs to be done inside the
appliance:
      * Edit /etc/xinet.d/tftp and change the line that says 'disable =
        yes' to 'enable = yes' and restart xinetd (we will use a normal
        tftpd for PXE booting, since dnsmasq can't do DHCP and TFTP
        separately on an interface, and we want TFTP only on the
        'public' interface eth0)
      * Edit /etc/sysconfig/network-scripts/ifcfg-eth0 and set
        HWADDR=52:54:00:22:83:50 and remove the line setting DNS1 (I
        don't think this is strictly necessary, but having the wrong
        HWADDR throws ifdown/ifup into knots)
      * Edit /etc/init.d/ovirt-wui-dev and remove the --enable-tftp and
        --tftp-root options from the dnsmasq invocation in start(). Then
        restart ovirt-wui-dev (could we put the dnsmasq options into
        dnsmasq.conf instead of hardcoding them in an init script ?)

(5) On your DNS server, enter the various SRV records that OVirt uses
(see the srv-host lines in the attached ovirt.conf dnsmasq snippet)

(6) On your DHCP server, make sure PXE clients are pointed to
ovirt.home.net as the TFTP server and told to download pxelinux.0 (the
dhcp-boot line in ovirt.conf)

(7) Don't forget to restart your DNS/DHCP server ;)

With that, you should be able to 
     1. do fun stuff like NFS mount your home dir into ovirt.home.net,
        just as you do for all your other machines or run a puppet
        client to customize the appliance in all the ways you customize
        your other machines 
     2. set your favorite VT enabled box to PXE boot, fire it up and
        watch it download and boot the managed node image
     3. boot fake nodes just as you could before

Now, if only I could figure out how to kinit against ovirt.home.net from
my laptop, I'd be completely happy (just putting the relevant bits from
[realms] and [domain_realm] into krb5.conf doesn't seem to do the trick)
Running firefox inside the WUI appliance is painfully slow.

David