To upgrade Jenkins without losing your data, download the latest jenkins.war file, copy it to /opt/bitnami/jenkins directory and restart Jenkins.
It is recommended to create a backup of the previous jenkins.war file. You may want to revert to the previous version if you find any issues after upgrading.
Upgrading only Jenkins
Execute the following steps to upgrade only Jenkins:
Stop the server:
$ sudo /opt/bitnami/ctlscript.sh stop jenkins
Copy your previous .war file in case you need to restore it:
$ mv /opt/bitnami/jenkins/jenkins.war /opt/bitnami/jenkins/jenkins.war.bak
Download the new version of Jenkins:
$ wget http://mirrors.jenkins-ci.org/war-stable/latest/jenkins.war --directory-prefix /opt/bitnami/jenkins/
Start the server:
$ sudo /opt/bitnami/ctlscript.sh start jenkins
Upgrading all the components
Start a new image with the latest Jenkins version and move the content of /bitnami/jenkins/home in your current installation to the new installation. Then, restart the server.