API change: adding a new config 'url' type

[Gustavo Niemeyer]

Hi Jim,

> Overview
> --------
>
> A common configuration requirement for a service is that the service
> units have access to the identical version of a given file. For
> example, this functionality can be used to configure the logo for a
> blog.

We do want to support first-class storage of files, and we actually
talked about that over the previous UDS. There are a few other
problems we want to solve in the way, though, and the proposal in this
specification is introducing a few problems:

- If we ever introduce a "url" setting type, it should be just that..
a value that is a URL that the user may enter and consume as desired.

- Injecting command line options of curl in the setting value is not
nice to work with, and certainly not a "URL". The dependency on the
curl command line at the heart of juju is also not something to be
taken lightly.

- Downloading the file onto the user's machine, possibly in a slow
link, just to upload it again seems unnecessary

- This is not addressing concerns we have regarding architecture dependency.

So, rather than fixing this specification, I suggest not worrying
about that now. Let's focus on the current problems we have at hand,
and come back to that once we have more time to think through how to
implement this properly, and act on it.

-- 
Gustavo Niemeyer
http://niemeyer.net
http://niemeyer.net/plus
http://niemeyer.net/twitter
http://niemeyer.net/blog

-- I'm not absolutely sure of anything.