How to upgrade from gitlab-ee_14.0.3-ee to latest version

Hi Team,
Kindly clarify below query

1.We have installed gitlab on ubuntu 18.04 so kindly let us know to how to upgrade from gitlab-ee_14.0.3-ee to latest version(16.8.2)
2.Kindly let us know the series of upgrade for GitLab & Ubuntu version (Gitlab 14.0.3 to Gitlab 16.8.2 & Ubuntu 18.04 to Ubuntu 23.0)

Everything is covered in the documentation. Except the ubuntu specific parts, but those are not really for this forum either.

There is no Ubuntu 23.0! There are 23.04 and 23.10, none of those are LTS releases, and GitLab only supports LTS releases. I suggest upgrading to the newest GitLab (at the moment 16.8.2) running on Ubuntu 22.04 and then upgrade the Ubuntu version to 24.04 when that is released in april.

I do not remember which versions of GitLab was released for Ubuntu 18.04, but as it was supported until some time last year, it’s probably most of the versions you’ll have to go through. But the general advice will be to upgrade GitLab as far as you can without changing the Ubuntu version, then upgrade to the next Ubuntu version and again upgrade GitLab as far as you can. In your case the next Ubuntu version will be 20.04, which is still supported, so you can reach GitLab 16.8.2 on that. You should probably still upgrade Ubuntu though.

The most important parts of an upgrade is:

1. Backup! If things (unexpectedly) go wrong, it’s really nice to have
2. Plan. Know what steps you have to go through
3. Follow the recommeded upgrade path. There’s a link to a tool from the documentation, but I also entered 14.0.3 into it, and got the following sequence of versions: 14.0.3 → 14.0.12 → 14.3.6 → 14.9.5 → 14.10.5 → 15.0.5 → 15.4.6 → 15.11.13 → 16.1.6 → 16.3.7 → 16.7.5 → 16.8.2. You’ll have to inject a switch of Ubuntu version somewhere .
   Note that these are only a part of the plan!
4. Let background migrations finish at each upgrade step.

Why don’t you follow the official instructions provided by Ubuntu? Or something isn’t working for you?
Sorry for asking, I’m thinking about the upgrade, and your question grabbed my attention.