On Wednesday, April 1, 2015 at 10:15:45 AM UTC-5, Guy Matz wrote:
>
> Hi! I have a process that is controlled by daemontools on some servers,
> and by init on other (i know, i know) and I need a way to have a Service
> definition when daemontools is not in the run.
>
> I've tried this:
> unless defined(Class['daemontools']) {
> notify { 'I Do not see daemontools': }
> service { $dw_service:
> ensure => 'running'
> }
> }
>
> but that didn't work. I've also tried Class['Daemontools'].
>
You are approaching the problem the wrong way. It is *never* a good idea
to base decisions about which classes and resources to declare on which
have already been declared at some particular point during catalog
building. Doing so introduces an evaluation-order dependency, which will
then hide in a dark corner, waiting for an opportunity to leap out and
clamp its jaws on your backside.
Ideally, you wouldn't even have to worry about this. If on all machines
you are using Puppet's idea of the default Service provider, then just
declare your service resource somewhere, without regard to whether it will
be handled by daemontools or not. All nodes that need the service get it
from the same declaration.
If you are using daemontools to handle the service of interest on some
machines where another provider (e.g. init) is the default, then you *still*,
at some level, want all nodes that need it to obtain it via the same
declaration. In that case, you must already have a means to know based on
node identity and/or facts whether your machines rely on daemontools. Use
that mechanism to control details of the service declaration, and any
ancillary declarations. A simple implemention of that might go thusly:
class myservice::service ($usedaemontools = 'false') {
include 'myservice::software'
service { 'myservice':
enable => true,
ensure => running,
provider => $usedaemontools ? {
'true' => 'daemontools',
default => undef
},
require => Package['myservice']
}
}
That same class would be declared for every node that needs service
"myservice"; a class parameter (preferably obtaining its value via
automatic data binding) determines whether the provider is overridden to
"daemontools".
Your needs may be more complex, but the same general idea can be applied.
It boils down to relying directly on data to determine what to declare, not
on what has already been declared.
John
--
You received this message because you are subscribed to the Google Groups
"Puppet Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to puppet-users+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/puppet-users/076de90e-196a-4f1d-bf77-96ad60586d36%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
