Fix bug in cert manager config (#15434)

* add test to cover cert manager config edge case

* fix edge case bug in cert manager config

pkg/reconciler/certificate/config/cert_manager.go

@@ -51,9 +51,9 @@ type CertManagerConfig struct {
 func NewCertManagerConfigFromConfigMap(configMap *corev1.ConfigMap) (*CertManagerConfig, error) {
 	// Use Knative self-signed ClusterIssuer as default
 	config := &CertManagerConfig{
-		IssuerRef:               knativeSelfSignedIssuer,
-		ClusterLocalIssuerRef:   knativeSelfSignedIssuer,
-		SystemInternalIssuerRef: knativeSelfSignedIssuer,
+		IssuerRef:               knativeSelfSignedIssuer.DeepCopy(),
+		ClusterLocalIssuerRef:   knativeSelfSignedIssuer.DeepCopy(),
+		SystemInternalIssuerRef: knativeSelfSignedIssuer.DeepCopy(),
 	}
 
 	if v, ok := configMap.Data[issuerRefKey]; ok {

pkg/reconciler/certificate/config/cert_manager_test.go

@@ -112,13 +112,41 @@ func TestIssuerRef(t *testing.T) {
 				Kind: "ClusterIssuer",
 			},
 		},
+		config: &corev1.ConfigMap{
+			ObjectMeta: metav1.ObjectMeta{
+				Namespace: system.Namespace(),
+				Name:      CertManagerConfigName,
+			},
+			Data: map[string]string{
+				systemInternalIssuerRef: "kind: ClusterIssuer\nname: system-internal-issuer",
+			},
+		},
+	}, {
+		name:    "all issuer valid",
+		wantErr: false,
+		wantConfig: &CertManagerConfig{
+			IssuerRef: &cmmeta.ObjectReference{
+				Name: "letsencrypt-issuer",
+				Kind: "ClusterIssuer",
+			},
+			ClusterLocalIssuerRef: &cmmeta.ObjectReference{
+				Name: "system-internal-issuer",
+				Kind: "ClusterIssuer",
+			},
+			SystemInternalIssuerRef: &cmmeta.ObjectReference{
+				Name: "system-internal-issuer",
+				Kind: "ClusterIssuer",
+			},
+		},
 		config: &corev1.ConfigMap{
 			ObjectMeta: metav1.ObjectMeta{
 				Namespace: system.Namespace(),
 				Name:      CertManagerConfigName,
 			},
 			Data: map[string]string{
 				clusterLocalIssuerRefKey: "kind: ClusterIssuer\nname: system-internal-issuer",
+				systemInternalIssuerRef:  "kind: ClusterIssuer\nname: system-internal-issuer",
+				issuerRefKey:             "kind: ClusterIssuer\nname: letsencrypt-issuer",
 			},
 		},
 	}}
@@ -129,7 +157,9 @@ func TestIssuerRef(t *testing.T) {
 			if (err != nil) != tt.wantErr {
 				t.Fatalf("Test: %q; NewCertManagerConfigFromConfigMap() error = %v, WantErr %v", tt.name, err, tt.wantErr)
 			}
-			if diff := cmp.Diff(actualConfig, tt.wantConfig); diff != "" {
+
+			if !cmp.Equal(actualConfig, tt.wantConfig) {
+				t.Log(cmp.Diff(actualConfig, tt.wantConfig))
 				t.Fatalf("Want %v, but got %v", tt.wantConfig, actualConfig)
 			}
 		})