[augeas-devel] Re: Augeas and Puppet

[David Lutterkort]

On Mon, 2008-08-04 at 16:39 +0200, Kjetil Torgrim Homme wrote:
> David Lutterkort <dlutter at redhat.com> writes:
> > As Bryan said, that's pretty close to how his Augeas type currently
> > works. You'd write
> >
> >         augeas { "some-random-name":
> >           context => "/files/etc/yum.repos.d",
> >           changes => [
> >             "set fedora.repo/fedora/enabled 1",
> >             "set fedora.repo/fedora/gpgcheck 1",
> >             "set fedora-updates.repo/fedora-updates/enabled 1",
> >             "set fedora-updates.repo/fedora-updates/gpgcheck 1"
> >           ]
> >         }
> >         
> > 'context' is just a convenience so you don't have to type the same
> > path prefix over and over, and all the relative paths in 'changes'
> > are relative to that.
> 
> this solves the atomicity problem very nicely, but it will be
> difficult for Augeas to find the filenames and lens(es) without
> evaluating all lenses.

Once the API supports it, there's no difficulty in expanding the type to
support 'lens' and 'filename' parameters, like

        augeas { "some-random-name":
                  context => "...",
                  changes => [ ... ],
                  files => "/files/etc/yum.repos.d/*.repo"
                  lens => "Yum.lns"
                }
        
Alternatively, setting up lens/filename mappings through a separate type
(augeas::transform) might also be a possibility.

> > For now, there's no way to specify a specific lens - the assumption
> > is that the lenses installed on the system agree with what you're
> > doing in your puppet manifest.
> 
> a reasonable assumption, I'm just worried about performance.

That's best addressed on actual performance measurements and data; there
are still many ways in which Augeas' performance can be improved.

> just agreeing
> on a cross-platform tree for network configuration is a very tall
> order, and I'm not even sure if it is right that Augeas enters this
> territory -- this should be handled by Puppet IMHO.

Yes, I briefly tried to address some of that, but it opens a very
unsavory can of worms, and I decided to leave that out.

David