NIFI-8614 Updated FileBasedClusterNodeFirewallFactoryBean to return default implementation

- FileBasedClusterNodeFirewallFactoryBean returns PermitAllClusterNodeFirewall instead of null to avoid having the Spring Framework return a NullBean in Spring Framework 5

Signed-off-by: Matthew Burgess <mattyb149@apache.org>

This closes #5082

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-cluster/src/main/java/org/apache/nifi/cluster/spring/FileBasedClusterNodeFirewallFactoryBean.java

@@ -18,6 +18,7 @@ package org.apache.nifi.cluster.spring;
 
 import java.io.File;
 
+import org.apache.nifi.cluster.firewall.ClusterNodeFirewall;
 import org.apache.nifi.cluster.firewall.impl.FileBasedClusterNodeFirewall;
 import org.apache.nifi.util.NiFiProperties;
 import org.springframework.beans.factory.FactoryBean;
@@ -25,18 +26,20 @@ import org.springframework.beans.factory.FactoryBean;
 /**
  * Factory bean for creating a singleton FileBasedClusterNodeFirewall instance.
  */
-public class FileBasedClusterNodeFirewallFactoryBean implements FactoryBean<FileBasedClusterNodeFirewall> {
+public class FileBasedClusterNodeFirewallFactoryBean implements FactoryBean<ClusterNodeFirewall> {
 
-    private FileBasedClusterNodeFirewall firewall;
+    private ClusterNodeFirewall firewall;
 
     private NiFiProperties properties;
 
     @Override
-    public FileBasedClusterNodeFirewall getObject() throws Exception {
+    public ClusterNodeFirewall getObject() throws Exception {
         if (firewall == null) {
             final File config = properties.getClusterNodeFirewallFile();
             final File restoreDirectory = properties.getRestoreDirectory();
-            if (config != null) {
+            if (config == null) {
+                firewall = new PermitAllClusterNodeFirewall();
+            } else {
                 firewall = new FileBasedClusterNodeFirewall(config, restoreDirectory);
             }
         }
@@ -44,8 +47,8 @@ public class FileBasedClusterNodeFirewallFactoryBean implements FactoryBean<File
     }
 
     @Override
-    public Class<FileBasedClusterNodeFirewall> getObjectType() {
-        return FileBasedClusterNodeFirewall.class;
+    public Class<ClusterNodeFirewall> getObjectType() {
+        return ClusterNodeFirewall.class;
     }
 
     @Override
@@ -56,4 +59,12 @@ public class FileBasedClusterNodeFirewallFactoryBean implements FactoryBean<File
     public void setProperties(NiFiProperties properties) {
         this.properties = properties;
     }
+
+    private static class PermitAllClusterNodeFirewall implements ClusterNodeFirewall {
+
+        @Override
+        public boolean isPermissible(final String hostOrIp) {
+            return true;
+        }
+    }
 }

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-cluster/src/test/java/org/apache/nifi/cluster/firewall/impl/FileBasedClusterNodeFirewallFactoryBeanTest.java

@@ -0,0 +1,73 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.cluster.firewall.impl;
+
+import org.apache.nifi.cluster.firewall.ClusterNodeFirewall;
+import org.apache.nifi.cluster.spring.FileBasedClusterNodeFirewallFactoryBean;
+import org.apache.nifi.util.NiFiProperties;
+import org.apache.nifi.util.StringUtils;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class FileBasedClusterNodeFirewallFactoryBeanTest {
+    private static final String PROPERTIES_SUFFIX = ".firewall.properties";
+
+    private FileBasedClusterNodeFirewallFactoryBean factoryBean;
+
+    private NiFiProperties properties;
+
+    @Before
+    public void setFactoryBean() {
+        properties = NiFiProperties.createBasicNiFiProperties(StringUtils.EMPTY);
+        factoryBean = new FileBasedClusterNodeFirewallFactoryBean();
+        factoryBean.setProperties(properties);
+    }
+
+    @Test
+    public void testGetObjectType() {
+        final Class<ClusterNodeFirewall> objectType = factoryBean.getObjectType();
+        assertEquals(ClusterNodeFirewall.class, objectType);
+    }
+
+    @Test
+    public void testGetObjectClusterNodeFirewallFileNotConfigured() throws Exception {
+        final ClusterNodeFirewall clusterNodeFirewall = factoryBean.getObject();
+        assertNotNull(clusterNodeFirewall);
+    }
+
+    @Test
+    public void testGetObjectClusterNodeFirewallFileConfigured() throws Exception {
+        final File firewallProperties = File.createTempFile(FileBasedClusterNodeFirewallFactoryBeanTest.class.getName(), PROPERTIES_SUFFIX);
+        firewallProperties.deleteOnExit();
+
+        final Map<String, String> beanProperties = new HashMap<>();
+        beanProperties.put(NiFiProperties.CLUSTER_FIREWALL_FILE, firewallProperties.getAbsolutePath());
+        properties = NiFiProperties.createBasicNiFiProperties(StringUtils.EMPTY, beanProperties);
+        factoryBean.setProperties(properties);
+
+        final ClusterNodeFirewall clusterNodeFirewall = factoryBean.getObject();
+        assertNotNull(clusterNodeFirewall);
+        assertEquals(FileBasedClusterNodeFirewall.class, clusterNodeFirewall.getClass());
+    }
+}