On Wed, 2011-06-01 at 12:18 -0400, Chris Lalancette wrote:
> 4) Export the name length restriction through some sort of deltacloud
> feature.
> Then the client can look at the restriction, and generate a name conforming
> to the restriction.
>
> Pros: Requires very little change in deltacloud itself. Pushes the problem
> out
> to the client
> Cons: Pushes the problem out to the client ;). Sort of breaks the cloud
> abstraction by having to have the client be smarter
>From the API side, I see this as the only practical option - anything
else would add some sort of application logic to the API. It would also
require some name remapping scheme: Deltacloud says the instance is
called 'frobnez' when the cloud provider calls it 'i-123476'. That means
there's yet another piece of data that admins need to hang on to, with
devastating consequences if they don't.
In practical terms, we already have a feature 'user_name' for instances
that indicates that the clouds supports user-supplied names. We could
just enhance the XML to include the maximum size, e.g.
<api driver="..." version="...">
<link href="http://localhost:3001/api/instances";
rel="instances">
<feature name="user_name">
<param name="name">
<constraint name="max_length"
value="20"/>
<constraint name="pattern"
value="[a-zA-Z0-9]+"/>
</param>
</feature>
</link>
</api>
(The pattern stuff as an example of something we don't need right now,
but might want to add at some point)
David
