[hotfix][docs][conf] Setup logging for generator

flink-docs/pom.xml

@@ -123,10 +123,12 @@ under the License.
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-log4j12</artifactId>
+			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>log4j</groupId>
 			<artifactId>log4j</artifactId>
+			<scope>compile</scope>
 		</dependency>
 
 		<dependency>

flink-docs/src/main/java/org/apache/flink/docs/configuration/ConfigOptionsDocGenerator.java

@@ -29,6 +29,9 @@
 import org.apache.flink.util.TimeUtils;
 import org.apache.flink.util.function.ThrowingConsumer;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
@@ -59,6 +62,8 @@
  */
 public class ConfigOptionsDocGenerator {
 
+	private static final Logger LOG = LoggerFactory.getLogger(ConfigOptionsDocGenerator.class);
+
 	static final OptionsClassLocation[] LOCATIONS = new OptionsClassLocation[]{
 		new OptionsClassLocation("flink-core", "org.apache.flink.configuration"),
 		new OptionsClassLocation("flink-runtime", "org.apache.flink.runtime.shuffle"),

flink-docs/src/main/resources/log4j.properties

@@ -0,0 +1,24 @@
+################################################################################
+#  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.
+################################################################################
+
+log4j.logger.org.apache.flink.docs.configuration.ConfigOptionsDocGenerator= INFO, logger
+
+log4j.appender.logger=org.apache.log4j.ConsoleAppender
+log4j.appender.logger.target = System.out
+log4j.appender.logger.layout=org.apache.log4j.PatternLayout
+log4j.appender.logger.layout.ConversionPattern=%-5p - %m%n