Azure CycleCloud is one of those products that shines, but slowly gets the care it needs. I was deploying a Slurm Scheduler and left the defaults for the scheduler, hpc and htc operating system selection. You can see the default is CentOS 8 which has been EOL as of Dec 31st, 2021. Ubuntu is an option, but if you want to continue using CentOS 8, keep reading.

When starting the cluster up, it eventually errored out trying to install the perl-switch RPM. Looks like this package has moved.

The great thing with CycleCloud is how flexible it is. Edit the cluster and select advanced settings to set the cloud-init section. Paste the following in to use a valid repo.
#cloud-config
runcmd:
- cd /tmp
- wget https://repo.almalinux.org/almalinux/8.4/PowerTools/x86_64/os/Packages/perl-Switch-2.17-10.el8.noarch.rpm
- yum -y install perl-Switch-2.17-10.el8.noarch.rpm

Success! The scheduler created 🙂

Now, I am sure the question you asked “why has Microsoft not updated CycleCloud?” I have no idea. Competing priorities? Hopefully, the next release will fix this, use Ubuntu in the drop down or just create your own CycleCloud template for a scheduler and select that during deployment with whatever OS image you prefer.