propagate deleteMachine annotation

Author: mweibel

azure/scope/machinepool.go

@@ -405,8 +405,27 @@ func (m *MachinePoolScope) applyAzureMachinePoolMachines(ctx context.Context) er
 	}
 
 	existingMachinesByProviderID := make(map[string]infrav1exp.AzureMachinePoolMachine, len(ampms))
-	for _, machine := range ampms {
-		existingMachinesByProviderID[machine.Spec.ProviderID] = machine
+	for _, ampm := range ampms {
+		// propagate Machine delete annotation from owner machine to AzureMachinePoolMachine
+		// this ensures setting a deleteMachine annotation on the Machine has an effect on the AzureMachinePoolMachine
+		// and the deployment strategy.
+		machine, err := util.GetOwnerMachine(ctx, m.client, ampm.ObjectMeta)
+		if err != nil {
+			// TODO(mw): which verbosity? info or error?
+			log.V(4).Info("failed to get owner machine", "machine", ampm.Spec.ProviderID)
+			continue
+		}
+		if machine != nil && machine.Annotations != nil {
+			if _, hasDeleteAnnotation := machine.Annotations[clusterv1.DeleteMachineAnnotation]; hasDeleteAnnotation {
+				log.V(4).Info("propagating DeleteMachineAnnotation", "machine", ampm.Spec.ProviderID)
+				if ampm.Annotations == nil {
+					ampm.Annotations = make(map[string]string)
+				}
+				ampm.Annotations[clusterv1.DeleteMachineAnnotation] = machine.Annotations[clusterv1.DeleteMachineAnnotation]
+			}
+		}
+
+		existingMachinesByProviderID[ampm.Spec.ProviderID] = ampm
 	}
 
 	// determine which machines need to be created to reflect the current state in Azure

azure/scope/machinepool_test.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"reflect"
 	"testing"
+	"time"
 
 	"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
 	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/authorization/armauthorization/v2"
@@ -1414,6 +1415,46 @@ func TestMachinePoolScope_applyAzureMachinePoolMachines(t *testing.T) {
 				g.Expect(list.Items).Should(HaveLen(1))
 			},
 		},
+		{
+			Name: "if MachinePool is not externally managed, and Machines have delete machine annotation, and overProvisionCount > 0, delete machines with deleteMachine annotation first",
+			Setup: func(mp *expv1.MachinePool, amp *infrav1exp.AzureMachinePool, vmssState *azure.VMSS, cb *fake.ClientBuilder) {
+				mp.Spec.Replicas = ptr.To[int32](2)
+
+				mpm1, ampm1 := getAzureMachinePoolMachineWithOwnerMachine(1)
+
+				mpm2, ampm2 := getAzureMachinePoolMachineWithOwnerMachine(2)
+				mpm2.Annotations = map[string]string{
+					clusterv1.DeleteMachineAnnotation: time.Now().String(),
+				}
+
+				mpm3, ampm3 := getAzureMachinePoolMachineWithOwnerMachine(3)
+				objects := []client.Object{&mpm1, &ampm1, &mpm2, &ampm2, &mpm3, &ampm3}
+				cb.WithObjects(objects...)
+
+				vmssState.Instances = []azure.VMSSVM{
+					{
+						ID:   "/subscriptions/123/resourceGroups/my-rg/providers/Microsoft.Compute/virtualMachineScaleSets/my-vmss/virtualMachines/1",
+						Name: "ampm1",
+					},
+					{
+						ID:   "/subscriptions/123/resourceGroups/my-rg/providers/Microsoft.Compute/virtualMachineScaleSets/my-vmss/virtualMachines/2",
+						Name: "ampm2",
+					},
+					{
+						ID:   "/subscriptions/123/resourceGroups/my-rg/providers/Microsoft.Compute/virtualMachineScaleSets/my-vmss/virtualMachines/3",
+						Name: "ampm3",
+					},
+				}
+			},
+			Verify: func(g *WithT, amp *infrav1exp.AzureMachinePool, c client.Client, err error) {
+				g.Expect(err).NotTo(HaveOccurred())
+				list := clusterv1.MachineList{}
+				g.Expect(c.List(ctx, &list)).NotTo(HaveOccurred())
+				g.Expect(list.Items).Should(HaveLen(2))
+				g.Expect(list.Items[0].Name).Should(Equal("mpm1"))
+				g.Expect(list.Items[1].Name).Should(Equal("mpm3"))
+			},
+		},
 		{
 			Name: "if existing MachinePool is not present, reduce replicas",
 			Setup: func(mp *expv1.MachinePool, amp *infrav1exp.AzureMachinePool, vmssState *azure.VMSS, cb *fake.ClientBuilder) {