How to update your Jenkins 2.176.x to 2.222.4 and java 8 to 11 in ubuntu 16.04 manually

This doc will tell you how to update your java to 11 and update Jenkins to version 2.222.4

1. Make sure the jenkins run in the quite mode

   http://your_jenkins_url/quietDown
   

2. Disconect all of your agent

3. Stop the jenkins server

4. Make backup of your server and agent

5. Update the java 11 (in this case I use adpotopenjdk11)

   sudo apt-get update
   sudo apt-get dist-upgrade
   sudo apt-get install -y apt-transport-https software-properties-common
   sudo apt-get install -y curl wget htop nano vim-tiny
   wget -qO - https://adoptopenjdk.jfrog.io/adoptopenjdk/api/gpg/key/public | sudo apt-key add -
   sudo add-apt-repository --yes https://adoptopenjdk.jfrog.io/adoptopenjdk/deb/
   sudo apt-get update
   sudo apt-get install -y adoptopenjdk-11-hotspot
   

6. Verify the java

   java -version
   javac -version
   

   If it's still using java8 you need to manually setup the java using alternatives

   update-java-alternatives --list
   update-java-alternatives --set adoptopenjdk-11-hotspot-amd64
   

   then check the java again

7. Relaunch the jenkins and make sure the pipelines runs well

8. Stop the jenkins server

9. Updates the jenkins.war

   wget http://mirrors.jenkins.io/war-stable/2.222.4/jenkins.war
   

   Backup your old jenkins.war

   Then move the new jenkins.war into your jenkins.war folder

10. Update your all of your agent java (you can use the same method as master)

11. Relaunch the jenkins server

12. Update all of your plugins

13. Then make sure the pipeline is running well