Command line CWL runner

[fmigneault]

Description

Weaver should provide a CLI CWL runner.

Its job would consist into doing the following steps:

1. deploy CWL file(s) as Application Package into a WPS/OGC-API process(es) (many if main file is class: Workflow)
2. execute the relevant process as job
3. monitor the job execution until completion
4. return the results (either direct JSON response or CWL outputs formatted)

This is essentially the same operations that are defined in current Workflow tests.
Changes required are to decouple the operations from pytest structure and add argparse/client class instead.

Motivation

This would serve many purposes:

• Provide a method to easily run a process simply by pointing at a Weaver/ADES/EMS URL and local CWL file, without the intricacies of forming the different HTTP requests.
• Provide a CLI to facilitate import in python and calling operations in notebooks
  Relates to:
  • https://www.crim.ca/jira/browse/DAC-169
  • https://www.crim.ca/jira/browse/DAC-198
  • https://www.crim.ca/jira/browse/DAC-203

edit: moved #381 in separate issue

[dbyrns]

Given the size of Weaver, what about having a small package that could be used directly in notebooks, by Weaver internally in tests or for calling ADES or in birdy which is using owslib.
Given the maturity of the new WPS/OGC-API process, maybe a contribution to owslib could also be evaluated?

[fmigneault]

I don't think there are any advantages to do it outside Weaver, since CWL is still disputed as the "official Application Package".
It would be easier to track compatibility between features supported by Weaver and its CLI.

Furthermore, most of the operations are already done here:
https://github.com/crim-ca/weaver/blob/fix-workflow-job-step-output/weaver/processes/wps3_process.py#L61-L416

Really only need to connect the deploy, execute, monitor and stage_job_results to a CLI.
It could be worth having a "basic" install though. When installing Weaver, minimal packages would be only requests related.

Definitely for higher scope of calling any WPS, it should be external.
That component should be able to communicate with Weaver with already deployed processes, maybe even use Weaver-CLI as an extension. Deployment itself is not core to OGC-API processes.

[dbyrns]

I agree, this is maybe premature, but Weaver does a lot of things that could eventually be packaged independantly to encourage contibutions. CWL engine is one thing, OGC-API processes implementation is another and the CLI could be a third. While Weaver could still use all of them, there are chances that, independantly, we could get external traction that is out of reach right now because of the service bundle.

[fmigneault]

There is already a draft for which I participated in owslib for OGC-API Processes implementation (though not yet merged...): https://github.com/geopython/OWSLib/pull/750/files

I would propose to define an abstract class with previously mentioned deploy, execute, monitor, etc. operations, which Weaver would provide an implementation. Given those, it should be relatively easy for birdy or others to instantiate the desired one.
Technically, OGC-API Processes are also supposed to implement a /conformance endpoint where features/extensions such as deploy are listed. This could help in the selection of the appropriate implementation.