Re: server iteration

[Tim Nelson]

On Wed, 25 May 2005, Tod Oace wrote:

> On May 24, 2005, at 21:01, Tim Nelson wrote:
>
> > > An interesting idea, but I would still have to double my quantity of 
> > > copy statements, yes? One set for the primary server and a second for 
> > > the alternate. Or am I misunderstanding?
> >
> >     That's why we need Templating in the next version of cfengine:
> > http://cfwiki.org/cfwiki/index.php/Templating_Ideas
> >
> >     Warning; the above documents a number of different templating ideas.
>
> Soooo... This seems like it could be a useful short-cut for defining copy 
> attributes, but I'm not seeing how it would handle failover. The way copy 
> works today I have to define a second copy action for each copy triggered by 
> a failover= class. Would copy templates do all that? And define 
> AddInstallable if that's still needed?
>
> It still seems useful even if it doesn't address my failover problem, 
> although I think I would be equally happy with a DefaultServer global 
> variable. I specify "server=${server}" for all but a couple of my copy 
> statements. And I really don't mind making owner=, group= and mode= very 
> explicit with each file/directory.
>
> Oh, I think template= is more Cfengine-like than use_template=.
> Like filter=.

        That one's not my idea, but I think it'd go like this:

Current setup:
------------------------------
copy:
        whatever::
                /filename
                        dest=/filename
                        mode=1234
                        owner=smurf
                        group=nonsmurf
                        define=foofoo

        whatever.foofoo::
                /filename
                        dest=/filename
                        mode=1234
                        owner=smurf
                        group=nonsmurf
------------------------------

Template setup:
------------------------------
copy:
        any::
                template_name=my_template
                        dest=/filename
                        mode=1234
                        owner=smurf
                        group=nonsmurf

        whatever::
                use_template=my_template
                        define=foofoo

        whatever.foofoo::
                use_template=my_template
------------------------------

        Supposedly simpler.

> > Naturally, I like the Action Templating one, as that's my idea :).
>
> This seems...tricky. But potentially very powerful.

	I'm essentially using Action Templating now, but I only have 
Post-Editing templating going now (that's even before Pre-copy).  It was 
my solution to defining multiple almost-identical copy statements.  I've 
basically packaged that up in cfengine-masterconf.

> So I'll add one other idea to the pile.
>
> What if you could embed Cfengine class rules and variables in the source file 
> being copied? This seems very Cfengine-like. Describe what you want and 
> Cfengine takes care of the rest. (It would still need to address the checksum 
> problem.)

	Hmm.  Well, that sounds like a job for an improved Editfiles.  You 
can find the Wiki page on that below:
http://cfwiki.org/cfwiki/index.php/Editfiles

	Both the Templating and Editfiles pages are linked to from the 
Wishlist on the Wiki.

	My basic approach is that I want lots of flexibility out of the 
system, and my approaches to both the Templating stuff and to Editfiles 
give that.  I don't know how cfenginely they are, but Editfiles always 
seemed a bit different than the rest of cfengine, and my suggestion 
separates it from cfengine, while still allowing the same actions that 
are currently possible.

        :)

--
Tim Nelson
Server Administrator
WebAlive Technologies Global
Level 1 Innovation Building, Digital Harbour
1010 LaTrobe Street
Docklands, Melbourne, 
Vic, 3008
Phone: +61 3 9934 0812
Fax: +61 3 9934 0899
E-mail: tim.nelson@webalive.biz
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