Question about channel

[Chris Tyler]

On Fri, 2011-07-22 at 10:06 -0400, Kiu Leung wrote:
> Dear all,
> 
> My name is Ken Leung.  I am trying to learn the terminology used by
> the koji build system.   I run into the term 'channel' and I don't
> really understand what a channel is.  So I should be grateful if
> somebody can give me a brief explanation.

Hi Ken,

A channel is a distinct queue for particular jobs. By default, most jobs
end up in the 'default' channel, except a few that end up in the
'createrepo' channel. This is useful where you want to have different
types of builders handle different types of jobs -- for example, repo
creation can be done on a machine of any architecture, so in the
fedora-arm koji system we have an x86_64 builder than handles the
createrepo channel while ARM builders handle the default channel.

You can create additional channels and use koji policy to manage how
they're used. In the fedora-arm koji system, we recently added a
tagbuild channel, and added this policy to the hub.conf:

[policy]
channel =
        method tagBuild :: use tagbuild
        method createrepo :: use createrepo

This forces tagBuild tasks into the tagbuild channel, which is handled
by specific builders. See http://fedoraproject.org/wiki/Koji/Policies
for information on policies.

-Chris