[rest-practices] rest-practices purpose

[Bryan Kearney]

On 04/27/2010 04:06 PM, Mark McLoughlin wrote:
> On Fri, 2010-04-23 at 10:32 -0400, Perry Myers wrote:
>
>> For cloud related efforts, we want to make sure that all of our usages of
>> REST are consistent wrt style/best practices.  Ideally, it would be best
>> if all Red Hat REST usage is on the same page.  But barring that, the
>> cloud usage should at least be consistent.
>>
>> So bburke's REST pages are certainly a good starting poing wrt
>> style/usage.  But Mark M. will also be maintaining a separate wiki page
>> (he'll provide the link) that is specific to cloud usage of REST.
>> Hopefully it won't duplicate all of the good work that bburke has done,
>> but instead will just point out style differences between his pages and
>> what cloud folks agree on.
>>
>> It will be expected that all cloud developers will conform to the style as
>> agreed upon in Mark's wiki page.
>
> Okay, I've taken a very rough first cut at this:
>
>    http://fedoraproject.org/wiki/Cloud_APIs_REST_Style_Guide
>
> Please feel free to edit or discuss here. Everything is still open for
> discussion. Please do try and keep topics in separate threads so that we
> can easily reference the discussion from the wiki.

Great first cut! Comments below


Intro
I will stop harping on this. But I like the idea of "levels" of the API 
based on the number of principals which you achieve.

Guidelines
- In XML: Can we assume all elements? This effects how we marshal to JSON.

- In urls, should query paramaters be puthon styled? Also. .I assume we 
use query parameters not form parameters.

- Another item to discuss would be return codes, and how to handle error 
messages. For example, we are using a specific http return code for 
error types. We do not have sub messages, but we put a localized message 
into a json blob in the body of the message which is returned. It would 
be nice to standardize on that message, and the use of return codes.

- Also, on return codes, it would be nice to standardize on the return 
codes. So.. should Creates (POST to FOO) return the new object and not a 
204? Should deletes return a 204?

- Another discussion we have had is on how to handle object graphs. Lets 
assume we have a resource model which is "Company -> Department -> 
Employee". We have assumed the API would start at a resource and "go 
down". So, in this case the following apis could be supported:

companies/{company_uuid}/departments/{dept_uuid}/employees/{emp_id}
departments/{dept_uuid}/employees/{emp_id}

However,  we would not support

departments/{dept_uuid}/company

- I assume urls and xml collections are plural resource names <departments>

- Finally, the last thing we discussed was how does security fit in with 
collections. We have assumed that if user 1 calls

companies/{company_uuid}/departments

they may see a different collection from user 2 based on their roles and 
permissions.

-- bk