feat: support for flux framework as hpc manager

Flux supports the majority of MPI flavors/variants, and can be used
to bootstrap MPI as a plugin. It adds other features for scheduling
and topology that can be used for simulations and ai/ml jobs.
This changeset adds the plugin implementation, including the
plugin module, tests, and an example with a small README to
serve as documentation for the time being.

Signed-off-by: vsoch <vsoch@users.noreply.github.com>

Author: vsoch

api/openapi-spec/swagger.json

@@ -0,0 +1,10 @@
+#!/bin/bash
+kind delete cluster
+kind create cluster
+make generate
+make manifests
+docker build -t ghcr.io/kubeflow/trainer/trainer-controller-manager -f ./cmd/trainer-controller-manager/Dockerfile .
+kind load docker-image ghcr.io/kubeflow/trainer/trainer-controller-manager
+kubectl apply --server-side -k ./manifests/overlays/manager
+sleep 20
+kubectl apply -f examples/flux/

api/python_api/kubeflow_trainer_api/models/__init__.py

@@ -47,6 +47,23 @@ spec:
                 description: mlPolicy provides the ML-specific parameters for the
                   model training.
                 properties:
+                  flux:
+                    description: flux policy source defines policy only for Flux
+                    properties:
+                      numProcPerNode:
+                        anyOf:
+                        - type: integer
+                        - type: string
+                        default: auto
+                        description: |-
+                          numProcPerNode is the number of processes per node.
+                          This is defined a level up on the MLPolicy directly.
+                        x-kubernetes-int-or-string: true
+                        x-kubernetes-validations:
+                        - message: NumProcPerNode must be equal to auto, cpu, gpu,
+                            or int value
+                          rule: self > 0 || self in ['auto', 'cpu', 'gpu']
+                    type: object
                   mpi:
                     description: mpi defines the configuration for the MPI Runtime.
                     properties:

api/python_api/kubeflow_trainer_api/models/trainer_v1alpha1_flux_ml_policy_source.py

@@ -47,6 +47,23 @@ spec:
                 description: mlPolicy provides the ML-specific parameters for the
                   model training.
                 properties:
+                  flux:
+                    description: flux policy source defines policy only for Flux
+                    properties:
+                      numProcPerNode:
+                        anyOf:
+                        - type: integer
+                        - type: string
+                        default: auto
+                        description: |-
+                          numProcPerNode is the number of processes per node.
+                          This is defined a level up on the MLPolicy directly.
+                        x-kubernetes-int-or-string: true
+                        x-kubernetes-validations:
+                        - message: NumProcPerNode must be equal to auto, cpu, gpu,
+                            or int value
+                          rule: self > 0 || self in ['auto', 'cpu', 'gpu']
+                    type: object
                   mpi:
                     description: mpi defines the configuration for the MPI Runtime.
                     properties: