incorporate review comments to use instance group name for DO instance group tag

pkg/model/domodel/BUILD.bazel

@@ -13,6 +13,7 @@ go_library(
         "//pkg/apis/kops:go_default_library",
         "//pkg/dns:go_default_library",
         "//pkg/model:go_default_library",
+        "//pkg/resources/digitalocean:go_default_library",
         "//upup/pkg/fi:go_default_library",
         "//upup/pkg/fi/cloudup/do:go_default_library",
         "//upup/pkg/fi/cloudup/dotasks:go_default_library",

pkg/model/domodel/droplets.go

@@ -21,6 +21,7 @@ import (
 	"strings"
 
 	"k8s.io/kops/pkg/model"
+	"k8s.io/kops/pkg/resources/digitalocean"
 	"k8s.io/kops/upup/pkg/fi"
 	"k8s.io/kops/upup/pkg/fi/cloudup/do"
 	"k8s.io/kops/upup/pkg/fi/cloudup/dotasks"
@@ -73,9 +74,9 @@ func (d *DropletBuilder) Build(c *fi.ModelBuilderContext) error {
 			clusterTagIndex := do.TagKubernetesClusterIndex + ":" + strconv.Itoa(masterIndexCount)
 			droplet.Tags = append(droplet.Tags, clusterTagIndex)
 			droplet.Tags = append(droplet.Tags, clusterMasterTag)
-			droplet.Tags = append(droplet.Tags, do.TagKubernetesClusterInstanceGroupPrefix+":"+"master-"+d.Cluster.Spec.Subnets[0].Region)
+			droplet.Tags = append(droplet.Tags, digitalocean.TagKubernetesInstanceGroup+":"+ig.Name)
 		} else {
-			droplet.Tags = append(droplet.Tags, do.TagKubernetesClusterInstanceGroupPrefix+":"+"nodes")
+			droplet.Tags = append(droplet.Tags, digitalocean.TagKubernetesInstanceGroup+":"+ig.Name)
 		}
 
 		userData, err := d.BootstrapScriptBuilder.ResourceNodeUp(c, ig)

pkg/resources/digitalocean/cloud.go

@@ -324,9 +324,7 @@ func getCloudGroups(c *Cloud, cluster *kops.Cluster, instancegroups []*kops.Inst
 // FindInstanceGroups finds instance groups matching the specified tags
 func FindInstanceGroups(c *Cloud, clusterName string) ([]DOInstanceGroup, error) {
 	var result []DOInstanceGroup
-	var masterDroplets []string
-	var workerDroplets []string
-	nodeExists := false
+	instanceGroupMap := make(map[string][]string) // map of instance group name with droplet ids
 
 	clusterTag := "KubernetesCluster:" + strings.Replace(clusterName, ".", "-", -1)
 	droplets, err := getAllDropletsByTag(c, clusterTag)
@@ -341,36 +339,14 @@ func FindInstanceGroups(c *Cloud, clusterName string) ([]DOInstanceGroup, error)
 			return nil, fmt.Errorf("get droplets Instance group for tags %v returned error. Error=%v", droplet.Tags, err)
 		}
 
-		if strings.Contains(doInstanceGroup, "master") {
-			// This is a master instance group, get the index.
-			k8sIndex, err := getDropletIndexFromTag(droplet.Tags)
-			if err != nil {
-				klog.Warningf("tag check returned err = %v", err)
-			}
-			instanceGroupName = fmt.Sprintf("%s-%s-%s", clusterName, doInstanceGroup, k8sIndex)
-
-			result = append(result, DOInstanceGroup{
-				InstanceGroupName: instanceGroupName,
-				GroupType:         "master",
-				ClusterName:       clusterName,
-				Members:           append(masterDroplets, strconv.Itoa(droplet.ID)),
-			})
-
-		} else if strings.Contains(doInstanceGroup, "nodes") {
-			// This is a node (add this instance group only once)
-			nodeExists = true
-			workerDroplets = append(workerDroplets, strconv.Itoa(droplet.ID))
-		}
-	}
-
-	if nodeExists {
-		instanceGroupName = fmt.Sprintf("%s-%s", clusterName, "nodes")
+		instanceGroupName = fmt.Sprintf("%s-%s", clusterName, doInstanceGroup)
+		instanceGroupMap[instanceGroupName] = append(instanceGroupMap[instanceGroupName], strconv.Itoa(droplet.ID))
 
 		result = append(result, DOInstanceGroup{
 			InstanceGroupName: instanceGroupName,
-			GroupType:         "node",
+			GroupType:         instanceGroupName,
 			ClusterName:       clusterName,
-			Members:           workerDroplets,
+			Members:           instanceGroupMap[instanceGroupName],
 		})
 	}
 
@@ -391,22 +367,7 @@ func getDropletInstanceGroup(tags []string) (string, error) {
 		}
 	}
 
-	return "", fmt.Errorf("Didn't find k8s-index for tag %v", tags)
-}
-
-func getDropletIndexFromTag(tags []string) (string, error) {
-	for _, tag := range tags {
-		klog.V(8).Infof("Check tag = %s", tag)
-		if strings.Contains(strings.ToLower(tag), TagKubernetesClusterIndex) {
-			tagParts := strings.Split(tag, ":")
-			if len(tagParts) < 2 {
-				return "", fmt.Errorf("tag split failed, too few components for tag %q", tag)
-			}
-			return tagParts[1], nil
-		}
-	}
-
-	return "", fmt.Errorf("Didn't find k8s-index for tag %v", tags)
+	return "", fmt.Errorf("Didn't find k8s-instancegroup for tag %v", tags)
 }
 
 // matchInstanceGroup filters a list of instancegroups for recognized cloud groups

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

@@ -28,7 +28,6 @@ const TagNameEtcdClusterPrefix = "etcdCluster-"
 const TagNameRolePrefix = "k8s.io/role/"
 const TagKubernetesClusterNamePrefix = "KubernetesCluster"
 const TagKubernetesClusterMasterPrefix = "KubernetesCluster-Master"
-const TagKubernetesClusterInstanceGroupPrefix = "kops-instancegroup"
 
 func SafeClusterName(clusterName string) string {
 	// DO does not support . in tags / names