Introduce ability to specify strategies for target allocation (#1079)

* Cribbed from another branch

* Refactor part 2

* Fix tests

* Remove deadlocking problem

* Update based on comments

* Unexported some fields, added blocker and comments about invariants

* Comments and imports fixed

Author: jaronoff97

apis/v1alpha1/opentelemetrycollector_types.go

@@ -108,6 +108,8 @@ type OpenTelemetryCollectorSpec struct {
 
 // OpenTelemetryTargetAllocator defines the configurations for the Prometheus target allocator.
 type OpenTelemetryTargetAllocator struct {
+	// AllocationStrategy determines which strategy the target allocator should use for allocation
+	AllocationStrategy string `json:"allocationStrategy,omitempty"`
 	// ServiceAccount indicates the name of an existing service account to use with this instance.
 	// +optional
 	ServiceAccount string `json:"serviceAccount,omitempty"`

apis/v1alpha1/zz_generated.deepcopy.go

@@ -683,6 +683,10 @@ spec:
                 description: TargetAllocator indicates a value which determines whether
                   to spawn a target allocation resource or not.
                 properties:
+                  allocationStrategy:
+                    description: AllocationStrategy determines which strategy the
+                      target allocator should use for allocation
+                    type: string
                   enabled:
                     description: Enabled indicates whether to use a target allocation
                       mechanism for Prometheus targets or not.