install kubectl and configure log4j in docker image

scripts/docker/zeppelin/bin/Dockerfile

@@ -92,6 +92,15 @@ RUN echo "$LOG_TAG Download Zeppelin binary" && \
     rm -rf /tmp/zeppelin-${Z_VERSION}-bin-all.tgz && \
     mv /zeppelin-${Z_VERSION}-bin-all ${Z_HOME}
 
+COPY log4j.properties ${Z_HOME}/conf/
+
+# Install kubectl
+RUN apt-get install -y apt-transport-https && \
+    curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add - && \
+    echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | tee -a /etc/apt/sources.list.d/kubernetes.list && \
+    apt-get update && \
+    apt-get install -y kubectl
+
 RUN echo "$LOG_TAG Cleanup" && \
     apt-get autoclean && \
     apt-get clean

scripts/docker/zeppelin/bin/log4j.properties

@@ -0,0 +1,22 @@
+#
+# 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.rootLogger = INFO, stdout
+
+log4j.appender.stdout = org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%5p [%d] ({%t} %F[%M]:%L) - %m%n