KAFKA-7896; Add sasl.jaas.config/sasl.mechanism props to the log4j kafka appender

This patch adds 2 props to the log4j kafka appender that get put directly
into the sasl properties passed to the producer:
    - ClientJaasConf: This property sets sasl.jaas.config
    - SaslMechanim: This property sets sasl.mechanism

Author: Rohan Desai <desai.p.rohan@gmail.com>

Reviewers: Manikumar Reddy <manikumar.reddy@gmail.com>

Closes #6216 from rodesai/add-kafka-appender-security-props

log4j-appender/src/main/java/org/apache/kafka/log4jappender/KafkaLog4jAppender.java

@@ -41,6 +41,8 @@ import static org.apache.kafka.clients.producer.ProducerConfig.KEY_SERIALIZER_CL
 import static org.apache.kafka.clients.producer.ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG;
 import static org.apache.kafka.clients.CommonClientConfigs.BOOTSTRAP_SERVERS_CONFIG;
 import static org.apache.kafka.clients.CommonClientConfigs.SECURITY_PROTOCOL_CONFIG;
+import static org.apache.kafka.common.config.SaslConfigs.SASL_JAAS_CONFIG;
+import static org.apache.kafka.common.config.SaslConfigs.SASL_MECHANISM;
 import static org.apache.kafka.common.config.SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG;
 import static org.apache.kafka.common.config.SslConfigs.SSL_TRUSTSTORE_PASSWORD_CONFIG;
 import static org.apache.kafka.common.config.SslConfigs.SSL_KEYSTORE_TYPE_CONFIG;
@@ -63,7 +65,9 @@ public class KafkaLog4jAppender extends AppenderSkeleton {
     private String sslKeystoreLocation;
     private String sslKeystorePassword;
     private String saslKerberosServiceName;
+    private String saslMechanism;
     private String clientJaasConfPath;
+    private String clientJaasConf;
     private String kerb5ConfPath;
     private Integer maxBlockMs;
 
@@ -210,6 +214,22 @@ public class KafkaLog4jAppender extends AppenderSkeleton {
         return clientJaasConfPath;
     }
 
+    public void setSaslMechanism(String saslMechanism) {
+        this.saslMechanism = saslMechanism;
+    }
+
+    public String getSaslMechanism() {
+        return this.saslMechanism;
+    }
+
+    public void setClientJaasConf(final String clientJaasConf) {
+        this.clientJaasConf = clientJaasConf;
+    }
+
+    public String getClientJaasConf() {
+        return this.clientJaasConf;
+    }
+
     public String getKerb5ConfPath() {
         return kerb5ConfPath;
     }
@@ -257,9 +277,15 @@ public class KafkaLog4jAppender extends AppenderSkeleton {
         if (securityProtocol != null && securityProtocol.contains("SASL") && saslKerberosServiceName != null && clientJaasConfPath != null) {
             props.put(SASL_KERBEROS_SERVICE_NAME, saslKerberosServiceName);
             System.setProperty("java.security.auth.login.config", clientJaasConfPath);
-            if (kerb5ConfPath != null) {
+        }
-                System.setProperty("java.security.krb5.conf", kerb5ConfPath);
+        if (kerb5ConfPath != null) {
-            }
+            System.setProperty("java.security.krb5.conf", kerb5ConfPath);
+        }
+        if (saslMechanism != null) {
+            props.put(SASL_MECHANISM, saslMechanism);
+        }
+        if (clientJaasConf != null) {
+            props.put(SASL_JAAS_CONFIG, clientJaasConf);
         }
         if (maxBlockMs != null) {
             props.put(MAX_BLOCK_MS_CONFIG, maxBlockMs);

log4j-appender/src/test/java/org/apache/kafka/log4jappender/KafkaLog4jAppenderTest.java

@@ -16,9 +16,14 @@
  */
 package org.apache.kafka.log4jappender;
 
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.hasItem;
+import static org.hamcrest.CoreMatchers.not;
+
 import org.apache.kafka.clients.producer.MockProducer;
 import org.apache.kafka.clients.producer.RecordMetadata;
 import org.apache.kafka.common.config.ConfigException;
+import org.apache.kafka.common.config.SaslConfigs;
 import org.apache.log4j.Logger;
 import org.apache.log4j.PropertyConfigurator;
 import org.apache.log4j.helpers.LogLog;
@@ -77,6 +82,45 @@ public class KafkaLog4jAppenderTest {
         }
     }
 
+    @Test
+    public void testSetSaslMechanism() {
+        Properties props = getLog4jConfig(false);
+        props.put("log4j.appender.KAFKA.SaslMechanism", "PLAIN");
+        PropertyConfigurator.configure(props);
+
+        MockKafkaLog4jAppender mockKafkaLog4jAppender = getMockKafkaLog4jAppender();
+        Assert.assertThat(
+            mockKafkaLog4jAppender.getProducerProperties().getProperty(SaslConfigs.SASL_MECHANISM),
+            equalTo("PLAIN"));
+    }
+
+    @Test
+    public void testSaslMechanismNotSet() {
+        testProducerPropertyNotSet(SaslConfigs.SASL_MECHANISM);
+    }
+
+    @Test
+    public void testSetJaasConfig() {
+        Properties props = getLog4jConfig(false);
+        props.put("log4j.appender.KAFKA.ClientJaasConf", "jaas-config");
+        PropertyConfigurator.configure(props);
+
+        MockKafkaLog4jAppender mockKafkaLog4jAppender = getMockKafkaLog4jAppender();
+        Assert.assertThat(
+            mockKafkaLog4jAppender.getProducerProperties().getProperty(SaslConfigs.SASL_JAAS_CONFIG),
+            equalTo("jaas-config"));
+    }
+
+    @Test
+    public void testJaasConfigNotSet() {
+        testProducerPropertyNotSet(SaslConfigs.SASL_JAAS_CONFIG);
+    }
+
+    private void testProducerPropertyNotSet(String name) {
+        PropertyConfigurator.configure(getLog4jConfig(false));
+        MockKafkaLog4jAppender mockKafkaLog4jAppender = getMockKafkaLog4jAppender();
+        Assert.assertThat(mockKafkaLog4jAppender.getProducerProperties().stringPropertyNames(), not(hasItem(name)));
+    }
 
     @Test
     public void testLog4jAppends() {

log4j-appender/src/test/java/org/apache/kafka/log4jappender/MockKafkaLog4jAppender.java

@@ -29,8 +29,11 @@ public class MockKafkaLog4jAppender extends KafkaLog4jAppender {
     private MockProducer<byte[], byte[]> mockProducer =
             new MockProducer<>(false, new MockSerializer(), new MockSerializer());
 
+    private Properties producerProperties;
+
     @Override
     protected Producer<byte[], byte[]> getKafkaProducer(Properties props) {
+        producerProperties = props;
         return mockProducer;
     }
 
@@ -49,4 +52,8 @@ public class MockKafkaLog4jAppender extends KafkaLog4jAppender {
     List<ProducerRecord<byte[], byte[]>> getHistory() {
         return mockProducer.history();
     }
+
+    public Properties getProducerProperties() {
+        return producerProperties;
+    }
 }