[Mageia-sysadm] Packaging puppet modules

[Buchan Milne]

----- "nicolas vigier" <boklm at mars-attacks.org> wrote:

> Hello,
> 
> We have now created a lot of puppet modules for different things used
> on Mageia servers. And I think many of them could be useful for other
> people installing servers. They are already available on our svn
> server,
> but I think we can do something better, to make them easier to use.
> 
> When trying to use puppet modules from other people that I found on
> the
> internet,

>From puppet forge (http://forge.puppetlabs.com/), or somewhere else?

> I usually have the following problems :
>  - modules are made for other distributions
>  - modules have dependencies on other modules, and it is not easy to
> see
>    which ones

And puppet-module (https://github.com/puppetlabs/puppet-module-tool) isn't able to resolve them?

>  - sometimes they can have dependency on an other module doing
> something
>    that you already do with a different module (for instance there is
> many
>    different apache httpd modules)
>  - modules come from unknow people, so you have to check them
> carefully
>    before using them
>  - you need to modify them to do what you want, because there often
> is
>    a lot of hardcoded values everywhere
> 
> So I think it could be interesting to provide some modules for
> Mageia,
> and distribute them as packages, doing the same as what we do for
> other
> software.

Well, the first question is, is servers a target use case of Mageia? If so, should we not rather draw up requirements for all the requirements for increasing the efficiency of managing Mageia servers? Possibly draw up reference architectures for different types of deployments?

> We could do something like this :
>  - one package per module
>  - modules installed in /usr/share/puppet/modules
>  - use rpm find-requires and find-provides to automatically manage
>    dependencies between modules
>  - remove any hardcoded values from modules, but use parameterised
>    classes, so you don't have to modify modules to use them
>  - setup puppet so that someone who wants to overwrite a module
> installed
>    by a package can create one with the same name in
> /etc/puppet/modules.
>    Or overwrite one template file.

+1

However, we may need to review what modules we would need, improve any of the ones we have developed (e.g. my Xymon one probably needs quite a bit of work).

> Then people using Mageia will be able to install puppet modules that
> are known to work with Mageia.
> 
> For instance, someone who wants to install a wordpress blog with a
> mysql
> database on a second server could do something like this very quickly
> :
> 
> # urpmi puppet-wordpress puppet-mysql
> # cat > /etc/puppet/manifests/site.pp <<EOF
> node server1 {
>   class { mysql::server:
>      dbtype => "innodb"
>   }
>   class { mysql::dbuser:
>      dbuser => 'wordpress',
>      dbpassword => 'password',
>   }
> }
> node server2 {
>   class { wordpress:
>      hostname => 'blog.example.com',
>      dbtype => 'mysql',
>      dbhost => 'server1.example.com',
>      dbuser => 'wordpress',
>      dbpassword => 'password',
>   }
> }
> EOF
> 
> Or someone who wants to setup a Mageia buildsystem to build his own
> packages :
> # urpmi puppet-mgabuildsystem
> # cat > /etc/puppet/manifests/site.pp <<EOF
> node mainnode {
>    class { mgabuildsystem::mainnode:
>       distribname => "My Distribution",
>       domain => "mydistribution.org",
>       ...
>    }
> }
> ...
> EOF

For quite some time I have been wanting to make a graphical tool for installing and configuring an LDAP server, using the online configuration (cn=config) capabilities of OpenLDAP, replacing 'openldap-mandriva-dit'. If it is possible to do this with puppet (I suspect not), I might consider a module for that (although, for the OpenLDAP project, it would probably be better to have a tool not dependent on puppet, so a Catalyst component was my original plan).

> Those module could also be used locally by some tools. For instance
> if
> we want to create a graphical tool like drakwizard, to setup some
> software
> on a machine. This graphical interface would ask some parameters,
> then
> install the corresponding puppet modules, generate a puppet file
> containing the parameters entered and run puppet on it locally.

What is the capability of Puppet Dashboard (http://www.puppetlabs.com/puppet/related-projects/dashboard/) ?

> However compared to what we do currently :
>  - it will be more work, to avoid hardcoding anything
>  - modules can become more complexe if they support more things
>  - we will have to be careful when changing API of released modules,
> or
>    write it in release notes so users of the packages know what they
> need
>    to change when updating to a newer release of the distribution.

Well, we may want to upstream modules as well, especially ones that we didn't write from scratch.

> So it is more work, but I think it can be worth it. We can maybe
> convince
> other Mageia packagers to help write puppet modules for the software
> they package.
> 
> A distribution providing puppet modules for many software would allow
> someone to install one or many servers very quickly and easily, and I
> think it would be very nice.
> 
> Maybe this is something that could be done for Mageia release 2 or
> later.
> So I plan to try to see if/how this could be done.
> 
> What do you think ?

I think we can try and package some modules we use that are well-tested, or any of ours that we believe are of sufficient quality now. 

But, while some of the contributors on this list may want to contribute to such a project, maybe it would be better to have a separate team/project/special interest group looking at the requirements/features for a server release. And, I think mandating puppet for this would be premature (from a design perspective), as there may be other better architectures/tools (e.g. Chef?).

Also, would there be any issue regarding support? Would we point support requests to Puppet Labs?

Regards,
Buchan