AWS: Ensure throughput setting is configured correctly on gp3 volumes

Author: jhixson74

pkg/webhooks/machine_webhook.go

@@ -799,6 +799,32 @@ func validateAWS(m *machinev1beta1.Machine, config *admissionConfig) (bool, []st
 
 	// TODO(alberto): Validate providerSpec.BlockDevices.
 	// https://github.com/openshift/cluster-api-provider-aws/pull/299#discussion_r433920532
+	for i, blockDevice := range providerSpec.BlockDevices {
+		ebs := blockDevice.EBS
+		if ebs == nil || ebs.VolumeType == nil || ebs.ThroughputMib == nil {
+			continue
+		}
+
+		throughputPath := field.NewPath("providerSpec", "blockDevices", "ebs", "throughputMib")
+		throughputValue := *ebs.ThroughputMib
+
+		if *ebs.VolumeType != "gp3" {
+			errs = append(errs, field.Invalid(
+				throughputPath,
+				throughputValue,
+				fmt.Sprintf("providerSpec.blockDevices[%d].ebs.throughputMib is only valid for gp3 volumes", i),
+			))
+			continue
+		}
+
+		if throughputValue < 125 || throughputValue > 2000 {
+			errs = append(errs, field.Invalid(
+				throughputPath,
+				throughputValue,
+				fmt.Sprintf("providerSpec.blockDevices[%d].ebs.throughputMib must be a value between 125 and 2000", i),
+			))
+		}
+	}
 
 	switch providerSpec.Placement.Tenancy {
 	case "", machinev1beta1.DefaultTenancy, machinev1beta1.DedicatedTenancy, machinev1beta1.HostTenancy: