Step By Step Jenkins Installation and Setup

Create three directories /jenkins , /tomcat and /java. and download these installables.

• wget http://mirror.cogentco.com/pub/apache/tomcat/tomcat-9/v9.0.10/bin/apache-tomcat-9.0.10.zip
• wget https://updates.jenkins-ci.org/download/war/2.121.1/jenkins.war

• sudo apt-get update
  sudo apt-get upgrade
  sudo apt-get install default-jdk

 

Installing Tomcat:

Step i. Just unzip tomcat  in  /tomcat  directory and open tomcat-users.xml file in vi mode, which is located under "/tomcat/apache-tomcat-9.0.10/conf/tomcat-users.xml"
.

Delete the text highlighted under yellow rectangle and replace it by below mentioned text:

  <role rolename="manager-script"/>

  <role rolename="manager-gui"/>

  <role rolename="manager-jmx"/>

  <role rolename="manager-status"/>

  <role rolename="admin-gui"/>

  <role rolename="admin-script"/>

  <user username="admin" password="admin123" roles="manager-gui,manager-script,manager-jmx,manager-status,admin-gui,admin-script"/>

Step ii:  Just update the context.xml file ( vi /tomcat/apache-tomcat-9.0.10/webapps/manager/META-INF/context.xml ). highted under yellow should be replaced by below mentioned command:
highlighted under yellow by below mentioned configuration.

allow="\d+\.\d+\.\d+\.\d+" />

By default, tomcat allows its adminconsole to be accessable only to IP address starting from 127.* ( That is your local host ),

http://localhost:8080 or http://127.0.0.1:8080

That means, if you unix box has IP address 192.168.10.15 ( or any IP ), by default tomcat url will not be accessible through your unix server IP or buy its DNS.

example : http://192.168.10.15:8080 or http://yourServerDNS:8080

After making suggested change, you can access tomcat through server's ip and DNS.

Step iii:  update Jenkin home in /tomcat/startup.sh

export JENKINS_HOME=/jenkins

 

 

By default, if we move jenkins.war file ( which we have downloaded ) under Tomcat's webapp directory then jenkin will be installed in your profile home path ( /home/jenkins ), but we want jenkins to be installed under /jenkin directory only. So, we are explicitly telling Tomcat to make /jenkin as home directory for my Jenkin.

 

Restart your Tomcat server. You are all set now.
Try to access tomcat admin console using user id /password that we set during step i .

User Id : admin
Password: admin123

 

 

Troubleshooting: If you are not able to login to tomcat, make sure your tomcat-users.xml should exactly look like the screenshot shown below:

Just unzip downloaded java tar.gz file under /java

tar -xvf jdk-8u171-linux-x64.tar.gz

add below mentioned lines at the end in .bashrc file ( refere last three lines in above screenshot to open .bashrc file ).

 

JAVA_HOME=/java/jdk1.8.0_171
export PATH=$JAVA_HOME/bin:$PATH

 

exit from the terminal and reopen new terminal on your linux/ubuntu or unix.

You should be able to see your installed java version and installed java path.

Your Java is all set.