Leapp ELevate CentOS 7 Helper

Overview

A BASH script designed to work with the Alma Linux ELevate tool to upgrade CentOS 7 servers to Rocky 8.

Alma Linux ELevate documentation can be found here
Yes, it's formatted as ELevate.

IMPORTANT
This script should be considered the basis for it's own work effort and not a complete script in and of itself.
It may be possible to run the script as is and successfully upgrade a server to Rocky 8, but there will likely need to be additional adjustments.
No warranties, ymmv.

Usage

• elevateHelper.sh, a BASH script for upgrading CentOS 7 to Rocky 8. Runs in three parts, a prep stage, upgrade stage and post-upgrade stage. Stages are elaborated on further below. Script will prompt user to check output from script at several points and is not a fire and forget script.
  Will always be proceeded by IMPORTANT: to help output stand out.
  Input requiring user input will also always be yellow.
  Usage, ./elevateHelper.sh STAGE
  Ex. ./elevateHelper.sh prep
  Ex. ./elevateHelper.sh upgrade
  Ex. ./elevateHelper.sh post
  Server also has built in help function that will output arguments and exit:
  Help, ./elevateHelper.sh help
  See Arguments section below for breakdown of acceptable arguments.
  

Upgrade stages

Script upgrades servers in three parts, below is a breakdown of what's approximately done in each stage.

• Prep, Prepare the server for upgrading. This stage is the most complicated and most likely to require manual intervention. Prep stage updates server, checks for duplicate packages, installs ELevate, runs pre-upgrade check, makes OS-level changes as documented from ELevate tests, and edits repo URLs from CentOS 7 to Rocky 8.
  Yum needs to be functional and the script will exit if yum fails at any point.
  This includes any chattr'd (immutable) yum files, the script will error out if any are found.
  As part of last step script will re-check if server is ready for Upgrade stage detailed below.
  If anything not encountered during testing is listed during this final check, it will require manual intervention.
  Script will prompt user if anything is found and will list the file to check and snippets of the error message.
  The following are checked as part of the prep function:
  
  • Is the script being run as root?
  • Is there enough disk space (10 GB) available?
  • Is the currently loaded kernel the newest of the available installed kernels being run?
• Upgrade, The most straightforward stage. Upgrades server from CentOS 7 to Rocky 8 using ELevate commands.
  For best results, run in screen session as process takes a while. Upgrade stage will reboot server when complete.
  Only issue I've run into during tests so far is not enough disk space being available.
  There are checks for this at the beginning that should catch this before getting to this point.
  During my tests I've found that approximately 10 GB of space is required.
  
• Post, Make post-upgrade changes/check. Re-install any software removed during prep stage, reconfigure any services and check for failed services.
  Pretty straightforward, just follow the prompts.
  One notable check is the script will check for any el7 packages not upgraded by ELevate.