$ ./gtp_exporter -h
usage: gtp_exporter [<flags>]
Flags:
  -h, --help               Show context-sensitive help (also try --help-long and --help-man).
      --web.listen-address=":9721"
                           Address on which to expose metrics and web interface.
      --web.telemetry-path="/metrics"
                           Path under which to expose metrics.
      --log.level=info     Only log messages with the given severity or above. One of: [debug, info, warn, error]
      --log.format=logfmt  Output format of log messages. One of: [logfmt, json]
      --version            Show application version.

# HELP gtp_devices The number of existing GTP devices.
# TYPE gtp_devices gauge
gtp_devices{name="s1u",role="GGSN"} 1 // should be "SGSN", but Kernel module doesn't have this value stored, and defaulted to "GGSN"
gtp_devices{name="s5u",role="GGSN"} 1
# HELP gtp_exporter_build_info A metric with a constant '1' value labeled by version, revision, branch, and goversion from which gtp_exporter was built.
# TYPE gtp_exporter_build_info gauge
gtp_exporter_build_info{branch="",goversion="go1.14.1",revision="",version=""} 1
# HELP gtp_info The information of GTP kernel module.
# TYPE gtp_info gauge
gtp_info{description="Interface driver for GTP encapsulated traffic",filename="/lib/modules/5.7.0-1.el7.elrepo.x86_64/kernel/drivers/net/gtp.ko",srcversion="191407DA5399304D93D62C7"} 1
# HELP gtp_tunnels The number of existing tunnels.
# TYPE gtp_tunnels gauge
gtp_tunnels{peer="192.168.200.1",version="1"} 1
gtp_tunnels{peer="192.168.200.5",version="1"} 1