[users at bb.net] Buildbot worker in Jenkins

[Povilas Kanapickas]

On 4/11/21 11:08 PM, Denis Ovsienko wrote:
> On Sun, 11 Apr 2021 22:40:59 +0300
> Povilas Kanapickas <povilas at radix.lt> wrote:
> 
> [...]
> 
>> In the past I've implemented support for a similar feature where I
>> Buildbot would suspend the host a worker is running on in order to
>> reduce noise and electricity costs. I haven't upstreamed all of this
>> work yet.
>>
>> It was quite a generic implementation, there's an arbitrary command to
>> start a machine and an arbitrary command to stop it. So you
>> potentially could hook this to start/stop Jenkins jobs.
> 
> Hi Povilas.
> 
> It is easy to see how the start command would fit the solution space
> (request the web hook URL when the master has a build request and is
> ready to use the worker, not immediately when any change had happened).
> 
> I guess the stop command would also request an URL, this time from
> the master HTTP API to initiate a graceful shutdown for the worker, is
> this correct?
> 
> Having written that, I suspect that the start and the stop commands do
> not need to be in the master or the worker code base. It could be a
> standalone cron job that uses the master HTTP API as follows:
> 
> ---------------------------------------------------------------
> w = the worker behind Jenkins
> if (w is offline AND has pending build requests)
> {
>   use Jenkins web hook to start the build that starts the worker
> }
> elif (w is online AND has no pending build requests)
> {
>   use the master HTTP API to request a graceful shutdown for the worker
> }
> ---------------------------------------------------------------
> 
> Would that be a better solution?
> 

I will check what code I have and create a PR if it rebases cleanly to
newer Buildbot. Then we have something concrete to discuss and it will
be clear how it could address your problem.

Cheers,
Povilas