Re: [Engine-devel] Requirements for Aeolus instance data injection.

On Wed, 2012-01-11 at 22:35 +0200, Dan Kenigsberg wrote: > On Wed, Jan 11, 2012 at 12:10:04PM -0800, David Lutterkort wrote: > > > > > > > > In practical terms, the blob of data should be > > > > passed to the > > > > 'start VM' call base64 encoded, and RHEV-M should > > > > decode it > > > > just > > > > before putting it into its proper place. > > > > > > This requirement is not clear, why not just pass data as > > > 'binary' to > > > 'start vm' and vdsm would write as is into the file, REST > > > already > > > knows how to encode/decode. > > > > I mostly mentioned base64 because that's how other API's (EC2, > > RAX) > > encode6 this data; to be pedantic, it's not REST that determines > > the > > encoding, but how the request payload is serialized (XML, JSON, > > application/x-www-form-urlencoded ..) The nice thing about base64 > > is > > that it works with all of them, without requiring add'l encoding, > > but > > ultimately anything works that allows passing arbitrary binary > > blobs as > > user_data. > > But base64 is the additional encoding... I'm generally reluctant to > intorduce > an application-level encoding if the transport already has one. > Does any REST > serializer have a problem with natively chewing binary data (I > really do not > know)? There's no such thing as a REST serializer; serialization is handled by whatever you use to process your payloads (XML, JSON, ...) and the libraries people use for that have to handle serialization-specific encodings; base64 is a little friendlier for really underpowered clients, like shell scripts. Don't underestimate how much people automate armed with little more than bash and curl - making that easy is one of the big attractions of REST.

David