Support openEO process definition

[fmigneault]

Description

Provide a handler for openEO.

Similar to how WPS and OGC API - Processes are remotely executed and monitored by handlers in https://github.com/crim-ca/weaver/tree/master/weaver/processes, requests could be sent toward an openEO server, since process listing and job submission is very similar conceptually to what OGC API - Processes accomplishes.

The media-type to submit an Application Package from openEO href has to be defined.

Also, given the nature of process listing that can be retrieved manually, openEO processes should be registrable as provider to keep the local references updated with the remote process definitions.

To Do

• Alternate representations retrieved using Accept: application/json; profile=openeo
• Alternate representations retrieved using ?profile=openeo
• Listing of processes using https://api.openeo.org/#tag/Process-Discovery
• Description of a process using https://api.openeo.org/#tag/User-Defined-Processes/operation/describe-custom-process
• Process Graphs https://api.openeo.org/#tag/Process-Discovery/operation/describe-custom-process
  (is it worth converting CWL, or simply define them as another UDP with a "cwl" runtime?).

References

• Mapping of fields to consider: Other process encodings? opengeospatial/ogcapi-processes#325 (comment)
• example server: https://dev.openeo.eurac.edu/processes
• openEO Process-Graph Content-Schema: https://api.openeo.org/assets/pg-schema.json
• API: https://api.openeo.org/
• client:
  • https://openeo.org/documentation/1.0/python/#processes
  • https://openeo.org/documentation/1.0/python/#applying-processes
• Relates to Support POST /jobs for various workflow implementations #716 (for profile=openeo job status)