allow KCP to Update when CoreDNS version doesn't change

Signed-off-by: killianmuldoon <[email protected]>
kubernetes-sigs · Jan 25, 2022 · cab94d2 · cab94d2
1 parent 917ab31
commit cab94d2
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Showing 4 changed files with 15 additions and 11 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 +500,7 @@ func (in *KubeadmControlPlane) validateCoreDNSVersion(prev *KubeadmControlPlane)
 		)
 		return allErrs
 	}
-
+	// Note: This check allows an "upgrade" in the case where the versions are equal.
 	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
@@ -744,6 +744,11 @@ 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 fail when using an invalid DNS build",
 			expectErr: true,
@@ -756,6 +761,7 @@ 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.go b/controlplane/kubeadm/internal/workload_cluster_coredns.go
@@ -412,10 +412,9 @@ func validateCoreDNSImageTag(fromTag, toTag string) error {
 	if err != nil {
 		return errors.Wrapf(err, "failed to parse CoreDNS target version %q", toTag)
 	}
-	// make sure that the version we're upgrading to is greater than the current one,
-	// or if they're the same version, the raw tags should be different (e.g. allow from `v1.17.4-somevendor.0` to `v1.17.4-somevendor.1`).
-	if x := from.Compare(to); x > 0 || (x == 0 && fromTag == toTag) {
-		return fmt.Errorf("toVersion %q must be greater than fromVersion %q", toTag, fromTag)
+	// make sure that the version we're upgrading to is greater than or equal to the current version.
+	if to.LT(from) {
+		return fmt.Errorf("toVersion %q must be greater than or equal to fromVersion %q", toTag, fromTag)
 	}
 	// check if the from version is even in the list of coredns versions
 	if _, ok := migration.Versions[fmt.Sprintf("%d.%d.%d", from.Major, from.Minor, from.Patch)]; !ok {

diff --git a/controlplane/kubeadm/internal/workload_cluster_coredns_test.go b/controlplane/kubeadm/internal/workload_cluster_coredns_test.go
@@ -491,17 +491,16 @@ func TestValidateCoreDNSImageTag(t *testing.T) {
 			toVer:           "1.6.1",
 			expectErrSubStr: "failed to parse CoreDNS current version",
 		},
+		{
+			name:    "fromVer is equal to toVer",
+			fromVer: "1.6.5",
+			toVer:   "1.6.5",
+		},
 		{
 			name:    "fromVer is equal to toVer, but different patch versions",
 			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",