[Gluster-devel] Feature page on Volume lifecycle extensions (aka Hooks)

[krish]

On 08/29/2012 01:21 PM, Deepak C Shetty wrote:
> On 08/28/2012 06:02 PM, krish wrote:
>> On 08/27/2012 01:42 PM, Deepak C Shetty wrote:
>>> On 08/24/2012 11:56 AM, Krishnan Parthasarathi wrote:
>>>> Hi list,
>>>>
>>>> The following wiki page provides detailed information on "Volume 
>>>> life cycle extensions"
>>>> or more fondly referred to as Hooks. Hooks are scripts/executables 
>>>> that would
>>>> be run on the trigger of events like volume-start, volume-stop, 
>>>> etc. This allows admin
>>>> to customise her volume 'deployment' work-flow. Of course it is not 
>>>> arbitrarily expressive/powerful
>>>> yet.
>>>>
>>>> http://www.gluster.org/community/documentation/index.php/Features/Hooks 
>>>>
>>>
>>> This (conceptually) is similar to hooks provided by oVirt/VDSM. I 
>>> have a naive Q tho'
>>> How to enable/disable a hook for a particular volume  ? Is it that 
>>> if i don't set any key=value for a particular volume, the hook won't 
>>> come into action. In other words hooks will use key=value to 
>>> determine what they need to do ?
>> Scripts whose name begin with 'S' are enabled and anything else would 
>> be disabled
>> I have updated the wiki with the answer to your question. Thanks for 
>> asking!
>> (See 
>> http://www.gluster.org/community/documentation/index.php/Features/Hooks#Detailed_Description)
>
> Hmm, still not clear. Let me reword my Q.
> Scripts that are enabled are not tied to a particular volume, rite ?
> Assuming that, if a script is enabled, then it would run/invoke for 
> all volumes. How do i control the running of a script at the volume 
> level ?
> Say i need to run a script for all volume except one.. how do i 
> control that ?
The scripts are tied to events (volume commands like set, start, stop 
etc) and __not__ to any volume.
The volume on which the script is 'applied' (or called for) is the 
volume on which the glusterd command is
executed. The script is supplied volname as a CLI argument, which it 
could use to conditionally execute actions
in the script for the given volume.

HTH,
krish