[occi-wg] Semantics of OCCI API: nouns and verbs

Richard Davies richard.davies at elastichosts.com
Thu Apr 16 08:05:54 CDT 2009

Sam Johnston wrote:
> > list, info, create, destroy, set are equivalent to CRUD;
> The CRUD operations map to HTTP verbs which were designed for making
> certain actions on a resource - I don't see that there's a need to repeat
> ourselves here by burning this information into the URL/request syntax.

Agreed in principle, but there's an implementation issue that many common
HTTP libraries will only do POST/GET, not PUT/DELETE, so need url versions
of 'UD' anyway.

Perhaps the compromise position is to work both ways:

POST/GET/PUT/DELETE /<object>  accepts all 4 CRUD operations
POST /<object>/set             alternative form of 'U' (if cannot PUT)
POST /<object>/destroy         alternative form of 'D' (if cannot DELETE)
POST /<object>/create          alternative form of 'C' (for symmetry)
GET /<object>/info             alternative form of 'R' (for symmetry)

> Non-CRUD operations such as start, stop, restart, clone, snapshot, etc.
> can be exposed by "actuator" URLs, which fits nicely with HATEOAS.

The actuator URLs for these can then fit in alongside the alternative
actuator forms of the CRUD operations themselves.



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