allow KCP to Update when CoreDNS version doesn't change

Signed-off-by: killianmuldoon <[email protected]>
kubernetes-sigs · Jan 26, 2022 · 7de85c6 · 7de85c6
1 parent 5b9922a
commit 7de85c6
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Showing 3 changed files with 23 additions and 7 deletions.
diff --git a/controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_webhook.go b/controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_webhook.go
@@ -500,7 +500,11 @@ func (in *KubeadmControlPlane) validateCoreDNSVersion(prev *KubeadmControlPlane)
 		)
 		return allErrs
 	}
-
+	// If the versions are equal return here without error.
+	// This allows an upgrades where the version of CoreDNS in use is not supported by the migration tool.
+	if toVersion.Equals(fromVersion) {
+		return allErrs
+	}
 	if err := migration.ValidUpMigration(fromVersion.String(), toVersion.String()); err != nil {
 		allErrs = append(
 			allErrs,

diff --git a/controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_webhook_test.go b/controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_webhook_test.go
@@ -484,6 +484,13 @@ func TestKubeadmControlPlaneValidateUpdate(t *testing.T) {
 			ImageTag:        "v1.6.6_foobar.2",
 		},
 	}
+	validUnsupportedCoreDNSVersion := dns.DeepCopy()
+	validUnsupportedCoreDNSVersion.Spec.KubeadmConfigSpec.ClusterConfiguration.DNS = bootstrapv1.DNS{
+		ImageMeta: bootstrapv1.ImageMeta{
+			ImageRepository: "gcr.io/capi-test",
+			ImageTag:        "v99.99.99",
+		},
+	}
 
 	unsetCoreDNSToVersion := dns.DeepCopy()
 	unsetCoreDNSToVersion.Spec.KubeadmConfigSpec.ClusterConfiguration.DNS = bootstrapv1.DNS{
@@ -744,6 +751,16 @@ func TestKubeadmControlPlaneValidateUpdate(t *testing.T) {
 			before:    before,
 			kcp:       dnsBuildTag,
 		},
+		{
+			name:   "should succeed when using the same CoreDNS version",
+			before: dns,
+			kcp:    dns.DeepCopy(),
+		},
+		{
+			name:   "should succeed when using the same CoreDNS version - not supported",
+			before: validUnsupportedCoreDNSVersion,
+			kcp:    validUnsupportedCoreDNSVersion,
+		},
 		{
 			name:      "should fail when using an invalid DNS build",
 			expectErr: true,
@@ -756,6 +773,7 @@ func TestKubeadmControlPlaneValidateUpdate(t *testing.T) {
 			before:    dns,
 			kcp:       dnsInvalidCoreDNSToVersion,
 		},
+
 		{
 			name:      "should fail when making a change to the cluster config's certificatesDir",
 			expectErr: true,

diff --git a/controlplane/kubeadm/internal/workload_cluster_coredns_test.go b/controlplane/kubeadm/internal/workload_cluster_coredns_test.go
@@ -496,12 +496,6 @@ func TestValidateCoreDNSImageTag(t *testing.T) {
 			fromVer: "1.6.5_foobar.1",
 			toVer:   "1.6.5_foobar.2",
 		},
-		{
-			name:            "fromVer is equal to toVer",
-			fromVer:         "1.6.5_foobar.1",
-			toVer:           "1.6.5_foobar.1",
-			expectErrSubStr: "must be greater",
-		},
 		{
 			name:    "fromVer is lower but has meta",
 			fromVer: "1.6.5-foobar.1",