From 362601cd664255602ba9c874475fdce8b80ae6e4 Mon Sep 17 00:00:00 2001
From: Ciprian Hacman <ciprian@hakman.dev>
Date: Wed, 21 Dec 2022 18:26:36 +0200
Subject: [PATCH 1/2] Allow migration from Gossip DNS to no DNS

---
 pkg/apis/kops/cluster.go                  | 6 +++---
 upup/pkg/fi/cloudup/template_functions.go | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/pkg/apis/kops/cluster.go b/pkg/apis/kops/cluster.go
index f18c679d63..81f65d8241 100644
--- a/pkg/apis/kops/cluster.go
+++ b/pkg/apis/kops/cluster.go
@@ -820,10 +820,10 @@ func (c *Cluster) IsSharedAzureRouteTable() bool {
 }
 
 func (c *Cluster) IsGossip() bool {
-	if dns.IsGossipClusterName(c.Name) {
-		return true
+	if c.UsesNoneDNS() || !dns.IsGossipClusterName(c.Name) {
+		return false
 	}
-	return false
+	return true
 }
 
 func (c *Cluster) UsesPublicDNS() bool {
diff --git a/upup/pkg/fi/cloudup/template_functions.go b/upup/pkg/fi/cloudup/template_functions.go
index 507268faae..6441128ea2 100644
--- a/upup/pkg/fi/cloudup/template_functions.go
+++ b/upup/pkg/fi/cloudup/template_functions.go
@@ -45,15 +45,14 @@ import (
 	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/klog/v2"
-	"k8s.io/kops/pkg/flagbuilder"
-	"sigs.k8s.io/yaml"
-
 	kopscontrollerconfig "k8s.io/kops/cmd/kops-controller/pkg/config"
 	"k8s.io/kops/pkg/apis/kops"
 	apiModel "k8s.io/kops/pkg/apis/kops/model"
 	"k8s.io/kops/pkg/apis/kops/util"
 	"k8s.io/kops/pkg/apis/nodeup"
+	"k8s.io/kops/pkg/dns"
 	"k8s.io/kops/pkg/featureflag"
+	"k8s.io/kops/pkg/flagbuilder"
 	"k8s.io/kops/pkg/kubemanifest"
 	"k8s.io/kops/pkg/model"
 	"k8s.io/kops/pkg/model/components/kopscontroller"
@@ -66,6 +65,7 @@ import (
 	gcetpm "k8s.io/kops/upup/pkg/fi/cloudup/gce/tpm"
 	"k8s.io/kops/upup/pkg/fi/cloudup/hetzner"
 	"k8s.io/kops/util/pkg/env"
+	"sigs.k8s.io/yaml"
 )
 
 // TemplateFunctions provides a collection of methods used throughout the templates
@@ -127,7 +127,7 @@ func (tf *TemplateFunctions) AddTo(dest template.FuncMap, secretStore fi.SecretS
 	dest["GossipDomains"] = func() []string {
 		var names []string
 
-		if cluster.IsGossip() {
+		if dns.IsGossipClusterName(cluster.Name) {
 			names = append(names, "k8s.local")
 		}
 

From b08d53a131535ef678e285cba99acd79cfc46053 Mon Sep 17 00:00:00 2001
From: Ciprian Hacman <ciprian@hakman.dev>
Date: Fri, 23 Dec 2022 08:04:13 +0200
Subject: [PATCH 2/2] Refactor Gossip usage in addon templates

---
 .../k8s-1.12.yaml.template                      |  8 ++++----
 .../k8s-1.16.yaml.template                      |  4 ++--
 upup/pkg/fi/cloudup/template_functions.go       | 17 ++++++++++-------
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/upup/models/cloudup/resources/addons/coredns.addons.k8s.io/k8s-1.12.yaml.template b/upup/models/cloudup/resources/addons/coredns.addons.k8s.io/k8s-1.12.yaml.template
index 71b43de01d..db376a4cb1 100644
--- a/upup/models/cloudup/resources/addons/coredns.addons.k8s.io/k8s-1.12.yaml.template
+++ b/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
diff --git a/upup/models/cloudup/resources/addons/kops-controller.addons.k8s.io/k8s-1.16.yaml.template b/upup/models/cloudup/resources/addons/kops-controller.addons.k8s.io/k8s-1.16.yaml.template
index 27a3a2e685..c5ea3352b8 100644
--- a/upup/models/cloudup/resources/addons/kops-controller.addons.k8s.io/k8s-1.16.yaml.template
+++ b/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:
diff --git a/upup/pkg/fi/cloudup/template_functions.go b/upup/pkg/fi/cloudup/template_functions.go
index 6441128ea2..fd1f7eb5d9 100644
--- a/upup/pkg/fi/cloudup/template_functions.go
+++ b/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 {