#!/bin/sh

# PROVIDE: prometheus
# REQUIRE: LOGIN
# KEYWORD: shutdown
#
# Add the following lines to /etc/rc.conf.local or /etc/rc.conf
# to enable this service:
#
# prometheus_enable (bool):     Set to NO by default
#                               Set it to YES to enable prometheus
# prometheus_user (string):     Set user to run prometheus
#                               Default is "prometheus"
# prometheus_group (string):    Set group to run prometheus
#                               Default is "prometheus"
# prometheus_data_dir (string): Set dir to run prometheus in
#                               Default is "/var/db/prometheus"
# prometheus_log_file (string): Set file that prometheus will log to
#                               Default is "/var/log/prometheus.log"
# prometheus_args (string):     Set additional command line arguments
#                               Default is ""

. /etc/rc.subr

name=prometheus
rcvar=prometheus_enable

load_rc_config $name

: ${prometheus_enable:="NO"}
: ${prometheus_user:="prometheus"}
: ${prometheus_group:="prometheus"}
: ${prometheus_config:="%%PREFIX%%/etc/prometheus.yml"}
: ${prometheus_data_dir:="/var/db/prometheus"}
: ${prometheus_log_file:="/var/log/prometheus.log"}
: ${prometheus_args:=""}

pidfile="/var/run/${name}.pid"
required_files="${prometheus_config}"
command="/usr/sbin/daemon"
procname="%%PREFIX%%/bin/${name}"
sig_reload="HUP"
extra_commands="reload"
command_args="-p ${pidfile} /usr/bin/env ${procname} \
                --config.file=${prometheus_config} \
                --storage.tsdb.path=${prometheus_data_dir} \
                ${prometheus_args} >> ${prometheus_log_file} 2>&1"

start_precmd=prometheus_startprecmd

# This checks for the existence of a prometheus 1.x data dir at the
# $prometheus_data_dir location. If one is found, Prometheus will not start.
prometheus_check_data_dir_version()
{
    local data_dir_version_file="${prometheus_data_dir}/VERSION"

    if [ -f "${data_dir_version_file}" ]; then
        local data_dir_version="0"

        read data_dir_version < "${data_dir_version_file}"

        if [ "${data_dir_version}" = "1" ]; then
            return 1
        fi
    fi
}

prometheus_startprecmd()
{
    if [ ! -e ${pidfile} ]; then
        install \
            -o ${prometheus_user} \
            -g ${prometheus_group} \
            /dev/null ${pidfile};
    fi
    if [ ! -f "${prometheus_log_file}" ]; then
        install \
            -o ${prometheus_user} \
            -g ${prometheus_group} \
            -m 640 \
            /dev/null ${prometheus_log_file};
    fi
    if [ ! -d ${prometheus_data_dir} ]; then
        install \
            -d \
            -o ${prometheus_user} \
            -g ${prometheus_group} \
            -m 750 \
            ${prometheus_data_dir}
    else
        # The directory already existed. Ensure it's not a prometheus 1.x
        # data dir.
        if ! prometheus_check_data_dir_version; then
            err 1 "Found net-mgmt/prometheus1 data dir, refusing to start."
        fi
    fi
}

load_rc_config $name
run_rc_command "$1"