Jenkins: Upgrading

Here are some notes on upgrading Jenkins with a WAR file.

Identify where the current war is running, by opening Jenkins, going to Manage Jenkins, and System Information.

Find the executable-war entry and note the path.

Stop Jenkins: sudo systemctl stop jenkins

Once stopped navigate to a folder where you can download things.

Download the latest version of Jenkins as a WAR file:

wget https://updates.jenkins-ci.org/latest/jenkins.war

Or, download a specific version:

wget https://updates.jenkins-ci.org/download/war/2.375.1/jenkins.war

Update the downloaded war file permissions:

chown root:root jenkins.war
chmod 644 jenkins.war

Now, make a backup of the existing war file (at the path from System Information):

mv /usr/share/java/jenkins.war /usr/share/java/jenkins.war.old

Copy the downloaded jenkins war file over the existing executable:

sudo mv /download/jenkins.war /usr/share/java/

NOTE: Be sure to change the folder path of the downloaded file.

You should be able to start the new version with:

sudo systemctl start jenkins