Update jenkins_installation.md

jenkins/jenkins_installation.md

@@ -6,41 +6,18 @@ Jenkins is a self-contained Java-based program, ready to run out-of-the-box, wit
 1. EC2 Instance 
    - With Internet Access
    - Security Group with Port `8080` open for internet
-1. Java v1.8.x 
+1. Java 11 should be installed  
 
-## Install Java
-1. We will be using open java for our demo, Get the latest version from http://openjdk.java.net/install/
-   ```sh
-   yum install java-1.8*
-   #yum -y install java-1.8.0-openjdk-devel
-   ```
-
-1. Confirm Java Version and set the java home
-   ```sh
-   java -version
-   find /usr/lib/jvm/java-1.8* | head -n 3
-   JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-<Java version which seen in the above output>
-   export JAVA_HOME
-   PATH=$PATH:$JAVA_HOME
-    # To set it permanently update your .bash_profile
-   vi ~/.bash_profile
-   ```
-   _The output should be something like this,_
-    ```sh
-   [root@~]# java -version
-   openjdk version "1.8.0_151"
-   OpenJDK Runtime Environment (build 1.8.0_151-b12)
-   OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)
-   ```
 
 ## Install Jenkins
  You can install jenkins using the rpm or by setting up the repo. We will set up the repo so that we can update it easily in the future.
 1. Get the latest version of jenkins from https://pkg.jenkins.io/redhat-stable/ and install
    ```sh
-   yum -y install wget
    sudo wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo
    sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key
-   yum -y install jenkins
+   yum install epel-release # repository that provides 'daemonize'
+   yum install java-11-openjdk-devel
+   yum install jenkins
    ```
 
    ### Start Jenkins