Use alpine and java 8 for docker images. (#10)

* Use alpine and java 8 for docker images.

* Remove installation of vim and redundant comment

Author: mccheah

resource-managers/kubernetes/docker-minimal-bundle/src/main/docker/driver/Dockerfile

@@ -1,12 +1,4 @@
-FROM ubuntu:trusty
-
-# Upgrade package index
-# install a few other useful packages plus Open Jdk 7
-# Remove unneeded /var/lib/apt/lists/* after install to reduce the
-# docker image size (by ~30MB)
-RUN apt-get update && \
-    apt-get install -y less openjdk-7-jre-headless net-tools vim-tiny sudo openssh-server procps && \
-    rm -rf /var/lib/apt/lists/*
+FROM anapsix/alpine-java:8
 
 RUN mkdir -p /opt/spark
 RUN mkdir -p /opt/spark/ui-resources/org/apache/spark/ui/static
@@ -18,7 +10,6 @@ ADD sbin /opt/spark/sbin
 ADD conf /opt/spark/conf
 
 ENV SPARK_HOME /opt/spark
-ENV JAVA_HOME /usr/lib/jvm/java-7-openjdk-amd64/jre
 
 WORKDIR /opt/spark
 

resource-managers/kubernetes/docker-minimal-bundle/src/main/docker/executor/Dockerfile

@@ -1,12 +1,4 @@
-FROM ubuntu:trusty
-
-# Upgrade package index
-# install a few other useful packages plus Open Jdk 7
-# Remove unneeded /var/lib/apt/lists/* after install to reduce the
-# docker image size (by ~30MB)
-RUN apt-get update && \
-    apt-get install -y less openjdk-7-jre-headless net-tools vim-tiny sudo openssh-server procps && \
-    rm -rf /var/lib/apt/lists/*
+FROM anapsix/alpine-java:8
 
 RUN mkdir -p /opt/spark
 RUN mkdir -p /opt/spark/ui-resources/org/apache/spark/ui/static
@@ -18,7 +10,6 @@ ADD sbin /opt/spark/sbin
 ADD conf /opt/spark/conf
 
 ENV SPARK_HOME /opt/spark
-ENV JAVA_HOME /usr/lib/jvm/java-7-openjdk-amd64/jre
 
 WORKDIR /opt/spark