test configs, and rationalize ephemeral

Author: jackfrancis

pkg/api/defaults.go

@@ -841,6 +841,9 @@ func (p *Properties) setAgentProfileDefaults(isUpgrade, isScale bool) {
 			if profile.OSDiskCachingType == "" {
 				profile.OSDiskCachingType = string(compute.CachingTypesReadOnly)
 			}
+			if profile.OSDiskType == "" {
+				profile.OSDiskType = StandardHDD
+			}
 		}
 
 		if profile.OSDiskCachingType == "" {

pkg/api/vlabs/const.go

@@ -198,3 +198,6 @@ const (
 	// AddonModeReconcile
 	AddonModeReconcile = "Reconcile"
 )
+
+// ScaleSetPrioritySpot means the ScaleSet will use Spot VMs
+const ScaleSetPrioritySpot = "Spot"

pkg/api/vlabs/validate.go

@@ -618,8 +618,8 @@ func (a *Properties) validateAgentPoolProfiles(isUpdate bool) error {
 			return e
 		}
 
-		if agentPoolProfile.IsEphemeral() {
-			log.Warnf("Ephemeral disks are enabled for Agent Pool %s. This feature in AKS-Engine is experimental, and data could be lost in some cases.", agentPoolProfile.Name)
+		if agentPoolProfile.IsEphemeral() && agentPoolProfile.ScaleSetPriority != ScaleSetPrioritySpot {
+			log.Warnf("Ephemeral OS disk is enabled for Agent Pool %s. This is an appropriate configuration for ephemeral nodes; data may be lost in some cases.", agentPoolProfile.Name)
 		}
 
 		if e := validateProximityPlacementGroupID(agentPoolProfile.ProximityPlacementGroupID); e != nil {

pkg/engine/virtualmachinescalesets.go

@@ -714,6 +714,7 @@ func CreateAgentVMSS(cs *api.ContainerService, profile *api.AgentPoolProfile) Vi
 		osDisk.DiffDiskSettings = &compute.DiffDiskSettings{
 			Option: compute.Local,
 		}
+		osDisk.ManagedDisk.StorageAccountType = compute.StorageAccountTypesStandardLRS
 	} else {
 		switch profile.OSDiskType {
 		case api.UltraSSD:

test/e2e/cluster.sh

@@ -6,7 +6,7 @@ TMP_DIR=$(mktemp -d "$(pwd)/XXXXXXXXXXXX")
 TMP_BASENAME=$(basename ${TMP_DIR})
 GOPATH="/go"
 WORK_DIR="/aks-engine"
-MASTER_VM_UPGRADE_SKU="${MASTER_VM_UPGRADE_SKU:-Standard_D4_v3}"
+MASTER_VM_UPGRADE_SKU="${MASTER_VM_UPGRADE_SKU:-Standard_D4s_v3}"
 NODE_VM_UPGRADE_SKU="${NODE_VM_UPGRADE_SKU:-Standard_D4_v3}"
 AZURE_ENV="${AZURE_ENV:-AzurePublicCloud}"
 IDENTITY_SYSTEM="${IDENTITY_SYSTEM:-azure_ad}"

test/e2e/test_cluster_configs/base.json

@@ -10,7 +10,9 @@
 		"SKIP_TESTS_AFTER_SCALE_DOWN": "true",
 		"SKIP_TESTS_AFTER_UPGRADE": "true",
 		"SKIP_TESTS_AFTER_SCALE_UP": "false",
-		"STABILITY_ITERATIONS": "0"
+		"STABILITY_ITERATIONS": "0",
+		"MASTER_VM_UPGRADE_SKU": "Standard_D4s_v3",
+		"NODE_VM_UPGRADE_SKU": "Standard_D4_v3"
 	},
 	"apiModel": {
 		"apiVersion": "vlabs",