Source address to send snmp from in the format 'address:port' to use when
connecting targets. If the port parameter is empty or '0', as in
'127.0.0.1:' or '[::1]:0', a source port number is automatically (random)
chosen.
Path to configuration file that can enable TLS or authentication. See:
https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md