Merge pull request #43892 from bsalamat/sched_conf1

Automatic merge from submit-queue

Scheduler can recieve its policy configuration from a ConfigMap

**What this PR does / why we need it**: This PR adds the ability to scheduler to receive its policy configuration from a ConfigMap. Before this, scheduler could receive its policy config only from a file. The logic to watch the ConfigMap object will be added in a subsequent PR.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #

**Special notes for your reviewer**:

**Release note**:

```Add the ability to the default scheduler to receive its policy configuration from a ConfigMap object.
```

plugin/pkg/scheduler/algorithm/scheduler_interface.go

@@ -41,4 +41,10 @@ type SchedulerExtender interface {
 // onto machines.
 type ScheduleAlgorithm interface {
 	Schedule(*v1.Pod, NodeLister) (selectedMachine string, err error)
+	// Predicates() returns a pointer to a map of predicate functions. This is
+	// exposed for testing.
+	Predicates() map[string]FitPredicate
+	// Prioritizers returns a slice of priority config. This is exposed for
+	// testing.
+	Prioritizers() []PriorityConfig
 }