I wanted to run a stop operation on all VMs in one of my HA groups in Proxmox and was frustrated to see there was no easy way to do so. I wrote a quick & dirty bash script that will let me start & stop all VMs within an HA group to do what I wanted.

#!/bin/bash
#Proxmox HA start/stop script
#Takes first argument of the operation to do (start / stop) and any additional arguments for which HA group(s) to do it on, then acts as requested.

if [[ "$1" != "start" && "$1" != "stop" ]]; then
    echo "Please provide desired state (start | stop)"
    exit 1
fi

if [ "$1" == "start" ]; then
    VM_STATE="started"
    OPERATION="Starting"
elif [ "$1" == "stop" ]; then
    VM_STATE="stopped"
    OPERATION="Stopping"
else exit 1 #should not ever get here
fi

#Loop through each argument except for the first
for group in "${@:-1}" 
do
    group_members=$(ha-manager config | grep -B1 $group | grep vm: )
    for VM in $group_members
    do
        echo "$OPERATION $VM in HA group $group"
        ha-manager set $VM --state $VM_STATE
    done
done