[Buildbot-devel] Buildbot with virtual machines

[Michael March]

On 8/18/06, Trevor Strohman <strohman at cs.umass.edu> wrote:
> I am building a "virtual" build farm, where almost all of my target
> platforms are virtual machines running on the same hardware.  I
> expect that eventually I will have 10 to 15 operating system images
> on a single dual processor machine (and perhaps more).  This machine
> also needs to have enough spare capacity to run a few other low-load
> services.
>
> Because there are so many virtual machines, I don't want them all to
> run at the same time.  Ideally, when a build is submitted, buildbot
> could launch some of the virtual machines, let them complete the
> build, then shut them down, then start a new batch of machines.
>
> Is this possible?  I don't mind modifying some code since I'll be
> writing my own system if buildbot doesn't work for me.
>
> Trevor


Trevor.. Please resist the temptation to roll your own solution. I
need, and have began working on (very early), the same solution. I
don't have time to write out a detailed explanation of what my plan is
so I'll try to get the gist out there...

Here are the highlights:

1. The system will be based on VMWare Server at first.. (but it
doesn't have to be..)
2. On each server that VMWare Server is running there will be a 'slave
proxy'. That proxy will read a conf file that will match every VM in
that VMWare Server's "inventory" (a VMWare Server term) to BuildBot
buildmaster.
3. Periodically, the 'slave master' will read its config file and for
every virtual slave that has an entry AND VMWare says its available,
it will make a TCP connection to the BuildBot slave to provide that "I
am here" heart beat.  So if there are 30 VMs in the config file, 30
TCP connections will be created.
4. If the BuildBot master requests a build, the 'slave proxy' will
start up (or resume) a VM. That BuildSlave will have the 'slave proxy'
set as its master.
5. The 'slave proxy' will relay all traffic to the master, watching
for the end of the build. At that time the VM slave will be suspended
to disk again.
6. At first the proxy will run builds serially, but later I plan to
add more complex scheduling rules.

This setup, if implemented, will accomplish two goals:

1. Be able to do builds on virtually unlimited amout of VMs regardless
of resources (except disk space.)
2. Little of no modifications to the BuildBot base code.

Does this sound like what you had in mind?

-- 
<admiral>

Michael F. March ----- mmarch at gmail.com
          "Seriously" - HSR