Update Jenkins core and plugins (2023Q2 edition)

Last time: #17969 (closed)

Preparation

• Go through the changelog, paying attention to changes on how agents connect to controller, config changes that may need update, important changes in plugins, etc.
  • Current version: 2.387.1
  • Available version: 2.401.1

May need attention:

• The default connection mode for the Java CLI client is now webSocket. You can specify http to continue to use the former default (for example because you are running Jenkins in a servlet container other than the recommended builtin Jetty, or because you are running an unusual reverse proxy which does not support WebSocket). You can also continue to specify ssh to use SSH transport (for example because you prefer to authenticate with a private key rather than an API token), or use a native SSH client. (pull 7605)

Deployment

• Deploy Jenkins upgrade to latest version available
• Use the Groovy and Python3 scripts to generate a list of up-to-date plugins
• Deploy plugin upgrades
• Restart all agents.
• Manually run the Update jobs script (may be needed so XML is valid with current Jenkins):

  sudo -u jenkins /usr/local/sbin/deploy_jenkins_jobs update

• Go through warnings in Jenkins interface.
• Manually uninstall removed plugins via Jenkins interface.
• Manually delete removed plugins from /var/lib/jenkins/plugins.

Wrap up

• Restart builds that were interrupted by Jenkins restart.
• Schedule next update.