set unmarshalling JSON with DiscardUnknown option (#7339)

Author: Devinwong

aks-node-controller/parser/testdata/test_aksnodeconfig_fields_unexpected.json

@@ -3,6 +3,7 @@
     "bootstrapping_config": {
         "bootstrapping_auth_method": "BOOTSTRAPPING_AUTH_METHOD_BOOTSTRAP_TOKEN"
     },
+    "unexpected_new_field1": "unexpected_new_value1",
     "cluster_config": {
         "vm_type": 2,
         "cluster_network_config": {
@@ -19,8 +20,7 @@
     "gpu_config": {
         "config_gpu_driver": true
     },
-    "unexpected_new_field1": "unexpected_new_value1",
     "unexpected_new_config2": {
         "unexpected_new_field2": "unexpected_new_value2"
     }
-}
+}

aks-node-controller/pkg/nodeconfigutils/utils.go

@@ -40,7 +40,9 @@ func MarshalConfigurationV1(cfg *aksnodeconfigv1.Configuration) ([]byte, error)
 
 func UnmarshalConfigurationV1(data []byte) (*aksnodeconfigv1.Configuration, error) {
 	cfg := &aksnodeconfigv1.Configuration{}
-	options := protojson.UnmarshalOptions{}
+	options := protojson.UnmarshalOptions{
+		DiscardUnknown: true, // ignore unknown fields to allow forward compatibility
+	}
 	err := options.Unmarshal(data, cfg)
 	return cfg, err
 }

aks-node-controller/pkg/nodeconfigutils/utils_test.go

@@ -60,7 +60,24 @@ func TestUnmarshalConfigurationV1(t *testing.T) {
 			wantErr: true,
 		},
 		{
-			name: "unknown field should error",
+			name: "string is assigned with a boolean value",
+			data: []byte(`{
+				"version": "v1",
+				"LinuxAdminUsername": true,
+				"authConfig": {
+					"subscriptionId": "test-subscription"
+				}
+			}`),
+			want: &aksnodeconfigv1.Configuration{
+				Version: "v1",
+				AuthConfig: &aksnodeconfigv1.AuthConfig{
+					SubscriptionId: "test-subscription",
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "unknown field should be ignored",
 			data: []byte(`{
 				"version": "v1",
 				"unknownField": "should be ignored",
@@ -74,7 +91,7 @@ func TestUnmarshalConfigurationV1(t *testing.T) {
 					SubscriptionId: "test-subscription",
 				},
 			},
-			wantErr: true,
+			wantErr: false,
 		},
 	}