Dockers – How to Get Started with Java8 Dev Environment

Following are the key points described later in this article:

• Java 8 Image Dockerfile
• Install Scripts to Install and Start Java8 Env

Java 8 Image Dockerfile

Following is Dockerfile for creating Java8 image. Name the file as java8_base.df.

# Base is the Centos environment
FROM centos:centos6

# Make the directories under which Java 8 will get installed
RUN mkdir /opt/jdk
RUN cd /opt

# Install wget and tar which will be used to download and unzip Java8 files
RUN yum -y install wget tar

# Download the files
RUN wget --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u5-b13/jdk-8u5-linux-x64.tar.gz

# Unzip in /opt/jdk folder
RUN tar -zxf jdk-8u5-linux-x64.tar.gz -C /opt/jdk

# Set the path for Java and Javac
RUN update-alternatives --install /usr/bin/java java /opt/jdk/jdk1.8.0_05/bin/java 100
RUN update-alternatives --install /usr/bin/javac javac /opt/jdk/jdk1.8.0_05/bin/javac 100

Install Scripts to Install and Start Java8 Env

Following scripts perform following two activities:

• If Java8 image, java8_base, is not found, it builds the Java8 image. This is one time activity.
• Stops and starts the container

One may name the script as “startJava8.sh” and use it such as “startJava8.sh j8” where j8 is the name of the container. Make sure to put both of the above files, java8_base.df and start8Java.sh in the same folder.

#!/bin/sh

if [ $# == 0 ]; then
  echo "This script expect container name argument. Example: ./installJava8.sh j8"
  exit 100
fi

docker stop $1;docker rm $1

# Build Java8 image if it does not exists
#
j8_image="java8_base"
j8_df="java8_base.df"
if [ `docker images $j8_image | wc -l` -lt 2 ]; then
  echo "Docker Image $j8_image do not exist..."
  echo "Builing docker image $j8_image"
  if [ -f $j8_df ]; then
    docker build -t $j8_image -f $j8_df .
  else
    echo "Can't find Dockerfile $j8_df in the current location"
    exit 200
  fi
fi

docker run --privileged=true -ti -dP --name $1 -v /c/Users:/mnt/Users $j8_image /bin/bash
docker exec -ti $1 /bin/bash