[Distutils] Buildout: caching of base configuration ('extends')

[Sebastien Douche]

On Wed, May 27, 2009 at 14:56, Thomas Lotze <thomas at thomas-lotze.de> wrote:
> Hi,

Hi Thomas :)
First at all, thank you for your work.

> I've been implementing a download API for buildout and have reached the
> point where I'd like to try using it for downloading the base config files
> referenced from a buildout config by the 'extends' option. This would have
> the benefit of allowing to cache those config files and being able to run
> a buildout using that feature while being offline.

Do you talk about index and find-links too? And for the bootstrap? I
search a scenario to deploy a buildout fully offline.

> - I think buildout should not unconditionally use a cached copy of a base
>  configuration file. While it is sensible in other use cases to never
>  access the network if a file is found in the cache, base configs can
>  be expected to change and should IMHO be taken from the cache only when
>  offline mode is active or an attempt at downloading failed.

Right. You think about "offline" option or "install-from-cache"
option? offline seems to be a good candidate.

> - The download cache to be used is configured as one of the options that
>  are read from either ~/.buildout/default.cfg or buildout.cfg and their
>  respective bases. In order to keep things simple, I'd suggest to use a
>  download cache only if specified directly inside any of these two files,
>  and ignore download-cache options in any downloaded base configs. This
>  would be an exception to how options read from config files are
>  combined, but one I deem worthwhile.

Good for me.

> Opinions?

Hmm, just an idea on the same area: caching only some packages (not
only "all" or "none"). Surely out of your scope...


-- 
Sebastien Douche <sdouche at gmail.com>