[ClusterLabs] [ClusterLabs Developers] Perl Modules for resource agents (was: Resource Agent language discussion)

[Jehan-Guillaume de Rorthais]

A quick top-post.

The project moved to its own repository. See:

  https://github.com/dalibo/PAF/

Any feedback on the perl modules and related questions bellow would still be
quite appreciated :)

Regards,

Le Thu, 26 Nov 2015 01:13:36 +0100,
Jehan-Guillaume de Rorthais <jgdr at dalibo.com> a écrit :

> Months are flying! Already 3 of them since my last answer...
> 
> I spent some time to port "ocf-shellfuncs", "ocf-returncodes" and
> "ocf-directories" shell scripts as perl modules called "OCF_Functions.pm",
> "OCF_ReturnCodes.pm" and "OCF_Directories.pm". They are currently
> hiding in our pgsql-resource-agent repository under the "multistate/lib"
> folder. See :
> 
>   https://github.com/dalibo/pgsql-resource-agent/
> 
> They are used from the "pgsqlms" resource agent available in the
> "multistate/script" folder. They are supposed to leave in
> "$OCF_ROOT//lib/heartbeat/". The pgsqlms agent has been tested again and again
> in various failure situations under CentOS 6 and CentOS 7. Modules seems to
> behave correctly.
> 
> Before considering pushing them out in a dedicated repository (or upstream?)
> where maintaining them would be easier, I would like to hear some feedback
> about them.
> 
> First, OCF_Functions does not implement all the shell functions available in
> ocf-shellfuncs. As a first step, I focused on a simple module supporting the
> popular functions we actually needed for our own agent. Let me know if I
> forgot a function that MUST be in this first version.
> 
> Second, "OCF_Directories.pm" is actually generated from
> "OCF_Directories.pm.PL". Because I can not rely on the upstream
> autogen/configure to detect the distribution specific destination folders, I
> wrote a wrapper in "multistate/Build.PL" around the "ocf-directories" shell
> script to export these variables in a temp file. Then when "building" the
> module, OCF_Directories.pm.PL read this temp file to produce the final
> distribution-dependent "OCF_Directories.pm". I don't like stuffing too much
> shell in perl scripts, but it's really like the autogen/configure process at
> the end of the day and this piece of code is only in the build process.
> 
> Cleaner ways would be to:
> 
>   * generate OCF_Directories.pm by the upstream ./configure which already have
>     all the logic
>   * re-implement the logic to find the appropriate destination folders in
>     "Build.PL". I am currently not able to follow this solution as reverse
>     engineering the autogen/configure process seems pretty difficult and time
>     consuming.
> 
> The libs are currently auto-installed with our pgsqlms agent following the
> quite standard way to install perl modules and scripts:
> 
>   perl Build.PL
>   perl Build
>   perl Build install
> 
> Any feedback, advice, patch etc would be appreciated!
> 
> PS: files are in attachment for ease of review.