Add validation to prevent Spot instances with capacity-reservations-only preference

Adds webhook validation to block conflicting configuration where
CapacityReservationPreference is set to 'capacity-reservations-only'
while MarketType is 'Spot', as this combination is not supported by AWS.

Author: BraeTroutman

api/v1beta2/awsmachine_webhook.go

@@ -386,6 +386,9 @@ func (r *AWSMachine) validateCapacityReservation() field.ErrorList {
 	if r.Spec.CapacityReservationID != nil && r.Spec.CapacityReservationPreference != CapacityReservationPreferenceOnly && r.Spec.CapacityReservationPreference != "" {
 		allErrs = append(allErrs, field.Forbidden(field.NewPath("spec", "capacityReservationPreference"), "when a reservation ID is specified, capacityReservationPreference may only be `capacity-reservations-only` or empty"))
 	}
+	if r.Spec.CapacityReservationPreference == CapacityReservationPreferenceOnly && r.Spec.SpotMarketOptions != nil && r.Spec.MarketType == MarketTypeSpot {
+		allErrs = append(allErrs, field.Forbidden(field.NewPath("spec", "capacityReservationPreference"), "when capacityReservationPreference is 'capacity-reservations-only', MarketType may not be 'Spot'"))
+	}
 	return allErrs
 }
 

api/v1beta2/awsmachine_webhook_test.go

@@ -241,7 +241,7 @@ func TestAWSMachineCreate(t *testing.T) {
 			wantErr: true,
 		},
 		{
-			name: "valid MarketType set to MarketTypeCapacityBlock is specified and CapacityReservationId is not provided",
+			name: "invalid MarketType set to MarketTypeCapacityBlock is specified and CapacityReservationId is not provided",
 			machine: &AWSMachine{
 				Spec: AWSMachineSpec{
 					MarketType:   MarketTypeCapacityBlock,
@@ -293,6 +293,18 @@ func TestAWSMachineCreate(t *testing.T) {
 			},
 			wantErr: false,
 		},
+		{
+			name: "invalid CapacityReservationPreference is `capacity-reservation-only` and MarketType is `Spot`",
+			machine: &AWSMachine{
+				Spec: AWSMachineSpec{
+					InstanceType:                  "test",
+					CapacityReservationID:         aws.String("cr-12345678901234567"),
+					CapacityReservationPreference: CapacityReservationPreferenceOnly,
+					MarketType:                    MarketTypeSpot,
+				},
+			},
+			wantErr: true,
+		},
 		{
 			name: "empty instance type not allowed",
 			machine: &AWSMachine{