Script monitors the other node in a 2-node proxmox cluster. If the other node becomes unavailable it will start the virtual machines on itself assuming they are HA enabled. This script only checks the status of the cluster quorum from the node it is running on.

Details

The VM start is triggered by setting the Expected Votes on the node to 1. This triggers Proxmox to start the HA Virtual Machines.
This program does not not perform any fencing functions!
Warning: If a network issue is preventing quorum and this program is running on both nodes, you may encounter a situation where both nodes start the HA VMs.

Setup

Setup a 2 node Proxmox cluster (v5.4-3 - 6.1-3) w/ ZFS local storage. (If shared storage is available, that would be preferrable)
Enable Virtual Machine replication to the other node every 5 minutes or so (If using shared storage, replication is not needed)
Add the Virtual Machine as a High Availability resource in the cluster
Deploy the service file and enable for start on boot

Deploying service

Make sure that the python3 path is correct
Set the correct path for the monitor_cluster.py script
Set the down_threshold
copy service file to /lib/systemd/system/
run systemctl daemon-reload to relaod the daemon
run systemctl enable monitor_cluser.service to start the service at boot
run systemctl start monitor_cluster.service to start the service now