[Unit]
Description=SNMP Exporter
After=network-online.target

# This assumes you are running snmp_exporter under the user "prometheus"

[Service]
User=prometheus
Restart=on-failure
ExecStart=/home/prometheus/snmp_exporter/snmp_exporter --config.file='/home/prometheus/snmp_exporter/snmp.yml'

[Install]
WantedBy=multi-user.target