Get a Proxmox VM's name via MAC address via API and use it in a telegraf override

proxmox_get_vm_name.sh

#!/bin/bash
PROXMOX_SERVER="pve:8006"
USERNAME="root@pam"
PASSWORD="<your pve password>"
NODE="pve"
INTERNAL_BRIDGE="vmbr1"
NIC="ens18" # nic name inside the vm to be templatized
MAC_ADDRESS="$(ip addr show $NIC | grep -m 1 -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}' | tr 'a-f' 'A-F' | head -n1)"

# Step 1: Login and get ticket and CSRF token
login_data=$(curl -k -s -d "username=$USERNAME&password=$PASSWORD" "https://$PROXMOX_SERVER/api2/json/access/ticket")
ticket=$(echo $login_data | jq -r '.data.ticket')
csrf_token=$(echo $login_data | jq -r '.data.CSRFPreventionToken')

# Step 2: List all VMs
vm_list=$(curl -k -s -b "PVEAuthCookie=$ticket" "https://$PROXMOX_SERVER/api2/json/cluster/resources?type=vm")

# Step 3: Loop through each VM to find the MAC address
vm_ids=$(echo $vm_list | jq -r '.data[].vmid')


for vm_id in $vm_ids; do
        vm_config=$(curl -k -s -b "PVEAuthCookie=$ticket" "https://$PROXMOX_SERVER/api2/json/nodes/$NODE/qemu/$vm_id/config" | jq '.data')
        net_keys=$(echo $vm_config | jq -r 'keys[] as $k | if $k | startswith("net") then $k else empty end')

        for net_key in $net_keys; do
                net_val=$(echo $vm_config | jq -r ".$net_key")
                vm_name=$(echo $vm_config | jq -r ".name")
                if [[ "$net_val" =~ .*"virtio=$MAC_ADDRESS".* && "$net_val" =~ .*"bridge=$INTERNAL_BRIDGE".* ]]; then
                        echo $vm_name
                        exit 0
                fi
        done
done

systemd_override_telegraf.conf

[Service]
ExecStart=
ExecStart=/usr/src/pvename/telegraf -config /etc/telegraf/telegraf.conf -config-directory /etc/telegraf/telegraf.d $TELEGRAF_OPTS

telegraf

#!/bin/sh
export HOSTNAME=$(pvename)
exec /usr/bin/telegraf $@