How to define an OCCI extension?

[TrinhLK]

As mentioned in the usertextocci.md, we can define a new tags named "my_stuff" as below
curl -v -X PUT -H 'Category: my_stuff; scheme="http://example.com/occi/my_stuff#"; class="mixin"; location="/my_stuff/"' http://localhost:8080/-/
I tried to define a new tag named "mlamp" (for LAMP case study, and there are several resources of mlamp such as tomcat, apache, etc.) as follows:
curl -v -X PUT -H 'Category: mlamp; scheme="http://occiware.org/mlamp#"; class="kind"; location="/mlamp/"' http://localhost:8080/-/
However, the result is:
< HTTP/1.1 400 Bad Request < Date: Tue, 19 May 2020 17:05:57 GMT < Server: OCCIWare MART Server v1.0 OCCI/1.2 < Accept: text/occi;application/json;application/occi+json;text/plain;text/occi+plain < Content-Type: application/json < Content-Length: 65 < { "message" : "you cannot use interface query on PUT method" }
Could you explain it please?

[philippemerle]

Replace class="kind" by class="mixin":
curl -v -X PUT -H 'Category: mlamp; scheme="http://occiware.org/mlamp#"; class="**mixin**"; location="/mlamp/"' http://localhost:8080/-/
The OCCI HTTP API only allows to create user mixins, i.e. mixins with no attributes.
To create mixins with attributes or kinds, you should develop an OCCI extension with the OCCIware Studio.