Upgrade Jenkins on CentOS

Question

I am trying to upgrade Jenkins from version 2.176.1 to 2.375.2. I tried two methods and both of them failed.

1. Method-1: Download the jenkins.war and copy it into /usr/lib/jenkins/ directory by replacing the original one. After copying, when I restart Jenkins, it simply fails to restart.

2. Method-2: Upgrade Jenkins' RPM using yum update jenkins. This command runs successfully and process exists without any error. But, again when I restart Jenkins, it fails to start.

CentOS version: CentOS-7

Answer 1

First of all - I can only support opinion of Dmitriy Tarasevich about reading upgrade guides. You can find theme here: https://www.jenkins.io/doc/upgrade-guide/

Then - stick to the version upgrade process that you've used previously (or for the first time with installation). If you did install it via .*war, don¨t worry and use your Method-1. On the other hand, if you used yum, stick to that method-2.

Then - such a "big" upgrade at once from 2.176.1 to 2.375.1 is, I'd say, the reason it's failing for you as the version in between contain several major/breaking changes (our team has faced the same problem (we "just" wanted to bump the versions too much after a long time of no upgrading and we've faced several problems we weren't able to solve together). So it was necessary to split it into several independent upgrades which appeared to be doable and we managed to get to LTS 2.375).

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To summarize recommended steps - I'd you need to:

1/ Split your upgrade into several steps and upgrade LTS more gradually: try to upgrade to first to some not-current LTS version. I believe something less than or precisely 2.303.3 could work and see if you can start it.

• then actually run Jenkins and check administration page,
• upgrade your plugins (if you want). FYI: this is recommended officially in Jenkins docs after every Jenkins core upgrade.
• check Jenkins administration page and apply necessary changes / manage necessary decision that might appear there (if applicable).

2/ Try to upgrade to a higher LTS version (repeat step 1 with its sub-steps)

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To be a very specific and give some examples (although I don't remember everything by hearth):

• you skipped a gradually upgrade to version 2.319 LTS that brings a major change of working with master node --> built-in node that needs to be applied (confirmed) from within the administration section of Jenkins (see docs: https://www.jenkins.io/doc/book/managing/built-in-node-migration/ )

• version 2.332.1 LTS brings an important change. I would say that you've hit exactly this issue (covered here): https://community.jenkins.io/t/jenkins-cant-find-java-after-update-running-on-centos-7/3615 - exact steps and more resources are within that thread and also here: https://www.jenkins.io/doc/upgrade-guide/2.332/#upgrading-to-jenkins-lts-2-332-1

• from version 2.361 LTS Jenkins requires Java 11 or higher (see docs https://www.jenkins.io/doc/upgrade-guide/2.361/ ). So - you will need to ensure that you have a proper Java installed (you already might have it though). Including your agents!. Otherwise you would start your Jenkins but it would not connect any agent (usually undesired state).

Please, try to make some gradual progress and let us know where you managed to get