Refactor Gossip usage in addon templates

upup/models/cloudup/resources/addons/coredns.addons.k8s.io/k8s-1.12.yaml.template

@@ -76,8 +76,8 @@ data:
           fallthrough in-addr.arpa ip6.arpa
           ttl 30
         }
-    {{- if GossipDomains }}
-        hosts /rootfs/etc/hosts {{ join " " GossipDomains }} {
+    {{- if GossipName }}
+        hosts /rootfs/etc/hosts k8s.local {
           ttl 30
           fallthrough
         }
@@ -167,7 +167,7 @@ spec:
         - name: config-volume
           mountPath: /etc/coredns
           readOnly: true
-{{- if GossipDomains }}
+{{- if GossipName }}
         - name: etc-hosts
           mountPath: /rootfs/etc/hosts
           readOnly: true
@@ -209,7 +209,7 @@ spec:
         - name: config-volume
           configMap:
             name: coredns
-{{- if GossipDomains }}
+{{- if GossipName }}
         - name: etc-hosts
           hostPath:
             path: /etc/hosts

upup/models/cloudup/resources/addons/kops-controller.addons.k8s.io/k8s-1.16.yaml.template

@@ -141,7 +141,7 @@ rules:
   - list
   - watch
   - patch
-{{- if GossipDomains }}
+{{- if GossipEnabled }}
 - apiGroups:
   - ""
   resources:
@@ -213,7 +213,7 @@ rules:
   - leases
   verbs:
   - create
-{{- if GossipDomains }}
+{{- if GossipEnabled }}
 - apiGroups:
   - ""
   resources:

upup/pkg/fi/cloudup/template_functions.go

@@ -124,14 +124,17 @@ func (tf *TemplateFunctions) AddTo(dest template.FuncMap, secretStore fi.SecretS
 		return cluster.Spec.KubeDNS
 	}
 
-	dest["GossipDomains"] = func() []string {
-		var names []string
-
-		if dns.IsGossipClusterName(cluster.Name) {
-			names = append(names, "k8s.local")
+	dest["GossipEnabled"] = func() bool {
+		if cluster.IsGossip() {
+			return true
 		}
-
-		return names
+		return false
+	}
+	dest["GossipName"] = func() bool {
+		if dns.IsGossipClusterName(cluster.Name) {
+			return true
+		}
+		return false
 	}
 
 	dest["NodeLocalDNSClusterIP"] = func() string {