Hey everyone -
Kinda new to all of this but I was able to get Libre running on centos8 and have moved on to oxidized. It doesn’t appear that there is a really clear set of instructions on this so here’s what I’ve done and I’ve been able to repeat it successfully in the lab and on my the prod box but please bear in mind, this is just the install. I don’t have it working… yet 
1 -check: ruby --version
ruby 2.5.5p157 (2019-03-15 revision 67260) [x86_64-linux] #the version I’m running
1a - sudo dnf install ruby #if ruby is not installed
2 - sudo useradd -c “oxidized system account” -m -d /etc/oxidized -s /bin/bash oxidized
#obviously make sure to set your password etc. I’ve also found a script or 2 that shows this as a system account, I’ll update when I’ve tested it both ways.
3 - sudo dnf -y group install “Development Tools”
4 - sudo dnf install make cmake which sqlite-devel ruby gcc ruby-devel libicu-devel gcc-c++
5 - sudo dnf install openssl-devel
6 - sudo gem install oxidized
7 - sudo gem install oxidized-script oxidized-web
and just for comparison, here’s my ./validate.php
====================================
| Component | Version |
|---|---|
| LibreNMS | 21.1.0-1-gaa634aa62 |
| DB Schema | 2020_11_02_164331_add_powerstate_enum_to_vminfo (191) |
| PHP | 7.3.20 |
| Python | 3.6.8 |
| MySQL | 10.3.27-MariaDB |
| RRDTool | 1.7.0 |
| SNMP | NET-SNMP 5.8 |
====================================
[OK] Composer Version: 2.0.8
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct
hope this helps someone. 