fetch deleteMachine annotation from Machine

In certain circumstances the deleteMachine annotation isn't yet
propagated from the Machine to the AzureMachinePoolMachine. This can
result in deleting the wrong machines. This change ensures the owner
Machine's deleteMachine annotation is always considered.

Author: mweibel

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) {