fix matchClusterConfiguration

kubernetes-sigs · Jul 17, 2020 · a75ad0e · a75ad0e
1 parent 19afe6c
commit a75ad0e
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/controlplane/kubeadm/internal/machinefilters/machine_filters.go b/controlplane/kubeadm/internal/machinefilters/machine_filters.go
@@ -277,7 +277,9 @@ func matchClusterConfiguration(kcp *controlplanev1.KubeadmControlPlane, machine
 	if ok {
 		machineClusterConfig := &kubeadmv1.ClusterConfiguration{}
 		// ClusterConfiguration annotation is not correct, only solution is to rollout.
-		if err := json.Unmarshal([]byte(machineClusterConfigStr), machineClusterConfig); err != nil {
+		// NOTE: it is required to handle a nil ClusterConfiguration (that is serialized into "null")
+		// see https://github.com/kubernetes-sigs/cluster-api/issues/3353
+		if err := json.Unmarshal([]byte(machineClusterConfigStr), &machineClusterConfig); err != nil {
 			return false
 		}
 		return reflect.DeepEqual(machineClusterConfig, kcp.Spec.KubeadmConfigSpec.ClusterConfiguration)

diff --git a/controlplane/kubeadm/internal/machinefilters/util_test.go b/controlplane/kubeadm/internal/machinefilters/util_test.go
@@ -90,6 +90,22 @@ func TestMatchClusterConfiguration(t *testing.T) {
 		}
 		g.Expect(matchClusterConfiguration(kcp, m)).To(gomega.BeFalse())
 	})
+	t.Run("Return true if cluster configuration is nil (special case)", func(t *testing.T) {
+		g := gomega.NewWithT(t)
+		kcp := &controlplanev1.KubeadmControlPlane{
+			Spec: controlplanev1.KubeadmControlPlaneSpec{
+				KubeadmConfigSpec: bootstrapv1.KubeadmConfigSpec{},
+			},
+		}
+		m := &clusterv1.Machine{
+			ObjectMeta: metav1.ObjectMeta{
+				Annotations: map[string]string{
+					controlplanev1.KubeadmClusterConfigurationAnnotation: "null",
+				},
+			},
+		}
+		g.Expect(matchClusterConfiguration(kcp, m)).To(gomega.BeTrue())
+	})
 }
 
 func TestGetAdjustedKcpConfig(t *testing.T) {