[CentOS-devel] Setting up fedmsg for centos

[Jan Chaloupka]

On 06/01/2015 03:28 PM, Karanbir Singh wrote:
> can we move this conversation to the centos-devel list please.
>
> - KB
>
> On 01/06/15 14:25, Jan Chaloupka wrote:
>> Hi,
>>
>> CentOS does not have any equivalent to fedmsg bus [1] at the moment.
>> What is it used for? Services (koji, pkgdb, ...) can send messages about
>> their state and result of tasks they run into the bus to notify other
>> service which can react accordingly. Thus creating a modular
>> infrastructure. E.g. koji send a message about finished build. Agent
>> read the message, trigger a jenkins job and run additional tests on the
>> build. Daily statistics about number of finished /failed builds can be
>> collected. Other application can have their own use cases. Example of
>> bus topology [4]. [5] is another source of some info about fedora
>> infrastructure.
>>
>> What needs to be done to set up the bus? Basic demo and setup of fedmsg,
>> fedmsg-relay is at [3]. First would be great to setup the bus for koji.
>> Koji runs on CentOS 6. fedpkg package is in epel6 repository [2]. We
>> will be needing fedmsg-hub, fedmsg-relay, koji-hub and koji-plugin parts
>> in the topology at the moment [4]. CentOS koji and Fedora koji are not
>> exacly the same but both APIs are compatible. So maybe take an
>> inspiration from Fedora's koji plugin. In order to set up bus and
>> clients, endpoints has to be set. Setting of endpoints is discussed at
>> [6]. Context of endpoints is described at [3]. Configuration files are
>> shared and must be the same on all machines using the bus. Bus messages
>> can be saved into database [7].
>>
>> What we can start with?
>> 1) create an instance of centos/fedora for fedmsg to run
>> 2) create/reuse koji plugin (where it can be found?)
>> 3) set/implement koji plugin to send messages for fedmsg
>>
>> What other application do you have in centos that could use fedmsg?
>>
>> Once there is a running msg bus, instances set, etc., it will be easier
>> to debug and test.
>>
>> Ralph, Pierre, what would be the optimal distribution of instances for
>> fedmsg? Is one instance of centos enough? What would be the best first
>> step to set up fedmsg? Where can I found koji-plugin, resp. its
>> implementation?

This question is confusing. I supposed fedmsg is a master and all 
services are slaves. However, as Pierre-Yves informed me there is no 
master. fedmsg bus is decentralized and distributed among all services. 
Thus thus the configuration distributed on each host.

>> This is only a discussion at the moment. Any other ideas are
>> appreciated. Other issues and problems will arise while configuring the
>> bus and koji.
>>
>> [1] https://github.com/fedora-infra/fedmsg/
>> [2] http://koji.fedoraproject.org/koji/buildinfo?buildID=630367
>> [3] http://fedmsg.readthedocs.org/en/latest/deployment/
>> [4] http://fedmsg.readthedocs.org/en/latest/topology/
>> [5] https://fedoraproject.org/wiki/Messaging_SIG
>> [6] http://fedmsg.readthedocs.org/en/latest/config/#term-endpoints
>> [7] http://fedmsg.readthedocs.org/en/latest/deployment/#store-all-messages
>>
>> Kind Regards
>> Jan
>