[chef-dev] Re: Re: CHEF-2880 debian policy and service provider

Tollef Fog Heen 
<
 >
 writes:

> ]] Bryan McLellan 
>
>> We're not crazy about adding resource method solely for this. The
>> simplest solution is to just run "invoke-rc.d --disclose-deny" all the
>> time. The big question here, is there a use case where you would have
>> the service disabled by policy but still want Chef to keep running if
>> you ask it to start it? Laurent? Thom? Tollef? (CHEF-597 [2])
>
> Well, invoke-rc.d is not what is used by init, invoke-rc.d is used by
> maintainer scripts to decide what, if anything, should be done on
> upgrades.
>
> The symlinks in /etc/rc$runlevel.d/ are usually what controls if a
> service should start.
>
> I think we shouldn't use invoke-rc.d, but rather use the service
> command.
>
> A use case for having policy-rc.d decline anything invoke-rc.d asks it
> would be to not restart services on upgrade, but rather handle that
> through chef or similar mechanisms.
>
> To solve Laurent's use case, I'd say just diverting the service command
> at the start and undiverting it afterwards would be just as sane as
> using policy-rc.d.

Hi, 

"invoke-rc.d is a generic interface  to  execute  System  V  style
init script  /etc/init.d/name  actions, obeying runlevel constraints
as well as any local policies set by the system administrator."

Another use case: I want to do some maintenance by hand, plenty of
recipes use the service resource with action :start. I don't want chef
to restart a service, some approaches:
1) i stop chef-client, here chef is restarted by a cron task if not
   running, i also stop cron (does that sound silly ? :) )
2) put a exit 0 on top of the init script (yuk)
3) i alter the recipe (or the provider) with a not_if
   ::File.exists?("/tmp/HEY_please_dont_start_#{servicename})
4) i use the policy-rc.d script to return 101 for the service in
   maintenance.

The policy-rc.d script only works for debian based systems.
Ever thought of a generic policy system for chef resources ?
It would be better than option 3) and could apply to resources and
possibly to recipes/cookbooks.

-- 
Laurent