#!/sbin/openrc-run
# Copyright 1999-2026 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# OpenRC translation of upstream docs/examples/conf/ntpd-rs-metrics.service.
#
# This is the SECOND daemon net-misc/ntpd-rs installs: a Prometheus/OpenMetrics
# exporter.  It is a different binary running under a different service account
# than ntpd-rs itself, which is why it gets its own service rather than being
# folded into that one.  It reads the ntp-daemon observation socket named in
# /etc/ntpd-rs/ntp.toml and serves metrics over HTTP (127.0.0.1:9975 default).
#
# It is not needed to keep time and upstream's own preset ships it disabled;
# add it to a runlevel only if you scrape it.
#
# THERE IS NO start_pre HERE, AND THAT IS DELIBERATE.  The unit declares
# RuntimeDirectory=ntpd-rs-observe, but nothing uses that directory: the string
# occurs nowhere in the 1.9.0 source outside the packaging documentation.  The
# exporter only reads the daemon's socket -- created world-readable, see
# default_observation_permissions() returning 0o666 in
# ntpd/src/daemon/config/mod.rs -- and binds a TCP port.  Measured on 1.9.0: it
# starts and serves as an unprivileged user with no runtime directory of its
# own and no capabilities.

description="Network Time Service (ntpd-rs) metrics exporter"

command="/usr/bin/ntp-metrics-exporter"
command_args="${NTPD_RS_METRICS_OPTS}"
command_user="ntpd-rs-observe:ntpd-rs-observe"
# Does not fork (measured on 1.9.0), same as ntp-daemon.
supervisor="supervise-daemon"

# Restart=always.  0 means unlimited respawns -- see supervise-daemon(8).
respawn_max="${NTPD_RS_METRICS_RESPAWN_MAX:-0}"

depend() {
	need net
	# Not `need`: the exporter starts and answers with errors while the
	# daemon is down, and pulling ntpd-rs into the runlevel as a side effect
	# of scraping it would be surprising.
	use ntpd-rs
}