rolling-update: log reason for InstanceGroup needing update

pkg/cloudinstances/cloud_instance_group.go

@@ -88,6 +88,7 @@ func (group *CloudInstanceGroup) AdjustNeedUpdate() {
 			if makeNotReady {
 				group.NeedUpdate = append(group.NeedUpdate, member)
 				member.Status = CloudInstanceStatusNeedsUpdate
+				fmt.Printf("InstanceGroup %s needs update: node %s has needs-update annotation\n", group.HumanName, member.Node.Name)
 			} else {
 				newReady = append(newReady, member)
 			}

pkg/resources/spotinst/resources.go

@@ -380,6 +380,7 @@ func registerCloudInstances(instanceGroup *cloudinstances.CloudInstanceGroup, no
 		status := cloudinstances.CloudInstanceStatusUpToDate
 		if newInstanceGroupName != currentInstanceGroupName {
 			status = cloudinstances.CloudInstanceStatusNeedsUpdate
+			fmt.Printf("InstanceGroup %s needs update: instance %s was created before last group update\n", currentInstanceGroupName, instance.Id())
 		}
 		if _, err := instanceGroup.NewCloudInstance(
 			instance.Id(), status, nodeMap[instance.Id()]); err != nil {

upup/pkg/fi/cloudup/awsup/aws_cloud.go

@@ -1045,6 +1045,7 @@ func awsBuildCloudInstanceGroup(ctx context.Context, c AWSCloud, cluster *kops.C
 			}
 			instanceSeen[*id] = true
 			addCloudInstanceData(cm, instances[aws.ToString(id)])
+			fmt.Printf("InstanceGroup %s needs update: instance %s is detached\n", cg.HumanName, *id)
 		}
 	}
 
@@ -1070,6 +1071,7 @@ func buildCloudInstance(i autoscalingtypes.Instance, instances map[string]*ec2ty
 	status := cloudinstances.CloudInstanceStatusUpToDate
 	if newConfigName != currentConfigName {
 		status = cloudinstances.CloudInstanceStatusNeedsUpdate
+		fmt.Printf("InstanceGroup %s needs update: instance %s launch configuration is behind\n", cg.HumanName, id)
 	}
 	cm, err := cg.NewCloudInstance(id, status, nodeMap[id])
 	if err != nil {

upup/pkg/fi/cloudup/gce/instancegroups.go

@@ -231,6 +231,7 @@ func GetCloudGroups(c GCECloud, cluster *kops.Cluster, instancegroups []*kops.In
 					g.Ready = append(g.Ready, cm)
 				} else {
 					g.NeedUpdate = append(g.NeedUpdate, cm)
+					fmt.Printf("InstanceGroup %s needs update: instance %s instance template is behind\n", g.HumanName, cm.ID)
 				}
 			}
 

upup/pkg/fi/cloudup/hetzner/cloud.go

@@ -376,6 +376,7 @@ func buildCloudInstanceGroup(ig *kops.InstanceGroup, sg []*hcloud.Server, nodeMa
 		status := cloudinstances.CloudInstanceStatusUpToDate
 		if _, ok := server.Labels[TagKubernetesInstanceNeedsUpdate]; ok {
 			status = cloudinstances.CloudInstanceStatusNeedsUpdate
+			fmt.Printf("InstanceGroup %s needs update: server %s has %s label\n", cloudInstanceGroup.HumanName, server.Name, TagKubernetesInstanceNeedsUpdate)
 		}
 
 		id := strconv.FormatInt(server.ID, 10)

upup/pkg/fi/cloudup/openstack/server_group.go

@@ -114,6 +114,7 @@ func osBuildCloudInstanceGroup(c OpenstackCloud, cluster *kops.Cluster, ig *kops
 		status := cloudinstances.CloudInstanceStatusUpToDate
 		if generationName != observedName || instance.Status == errorStatus {
 			status = cloudinstances.CloudInstanceStatusNeedsUpdate
+			fmt.Printf("InstanceGroup %s needs update: instance %s generation mismatch or in error state\n", cg.HumanName, instance.ID)
 		}
 		cm, err := cg.NewCloudInstance(instance.ID, status, nodeMap[instance.ID])
 		if err != nil {

upup/pkg/fi/cloudup/scaleway/cloud.go

@@ -399,6 +399,7 @@ func buildCloudGroup(s *scwCloudImplementation, ig *kops.InstanceGroup, sg []*in
 		for _, tag := range server.Tags {
 			if tag == TagNeedsUpdate {
 				status = cloudinstances.CloudInstanceStatusNeedsUpdate
+				fmt.Printf("InstanceGroup %s needs update: server %s has %s tag\n", cloudInstanceGroup.HumanName, server.Name, TagNeedsUpdate)
 			}
 		}
 		cloudInstance, err := cloudInstanceGroup.NewCloudInstance(server.ID, status, nodeMap[server.ID])