prometheus-statsd-exporter: switch config to openwrt interface names

Drop the config knobs '*_address' and introduce '*_interface'
and '*_ipv6' instead.

'*_interface' takes an openwrt interface name ('loopback', 'lan',
'wan' etc), from which the primary IP is used to listen on. If
the matching '*_ipv6' is set to '1', the IPv6 adress will be used,
IPv4 elsewise.

procd interface triggers are now combined with this, so if a listen
interface is not yet configured when the init script is executed, the
process start is defered, and the trigger takes care of that once
the interfaces are ready.

Signed-off-by: Andre Heider <a.heider@gmail.com>

utils/prometheus-statsd-exporter/files/etc/config/prometheus-statsd-exporter

@@ -1,6 +1,12 @@
 config prometheus-statsd-exporter 'main'
-	option web_listen_address '127.0.0.1:9102'
+	option web_interface 'loopback'
+	option web_port '9102'
+	option web_ipv6 '0'
 	option web_telemetry_path '/metrics'
-	option statsd_listen_udp '127.0.0.1:9125'
-	option statsd_listen_tcp '127.0.0.1:9125'
+	option statsd_udp_interface 'loopback'
+	option statsd_udp_port '9125'
+	option statsd_udp_ipv6 '0'
+	option statsd_tcp_interface 'loopback'
+	option statsd_tcp_port '9125'
+	option statsd_tcp_ipv6 '0'
 	option statsd_mapping_config '/etc/prometheus-statsd-exporter.yml'

utils/prometheus-statsd-exporter/files/etc/init.d/prometheus-statsd-exporter

@@ -6,30 +6,92 @@ USE_PROCD=1
 PROG=/usr/bin/statsd_exporter
 CONFFILE=/etc/prometheus-statsd-exporter.yml
 
+. /lib/functions/network.sh
+
+_log() {
+	logger -p daemon.info -t prometheus-statsd-exporter "$@"
+}
+
 start_service() {
-	local web_listen_address
+	local web_interface web_port web_ipv6
 	local web_telemetry_path
-	local statsd_listen_udp
-	local statsd_listen_tcp
+	local statsd_udp_interface statsd_udp_port statsd_udp_ipv6
+	local statsd_tcp_interface statsd_tcp_port statsd_tcp_ipv6
 	local statsd_mapping_config
+	local web_ip statsd_udp_ip statsd_tcp_ip
+
 	config_load "prometheus-statsd-exporter"
-	config_get web_listen_address main web_listen_address "127.0.0.1:9102"
+	config_get web_interface main web_interface "loopback"
+	config_get web_port main web_port "9102"
+	config_get web_ipv6 main web_ipv6 "0"
 	config_get web_telemetry_path main web_telemetry_path "/metrics"
-	config_get statsd_listen_udp main statsd_listen_udp "127.0.0.1:9125"
-	config_get statsd_listen_tcp main statsd_listen_tcp "127.0.0.1:9125"
+	config_get statsd_udp_interface main statsd_udp_interface "loopback"
+	config_get statsd_udp_port main statsd_udp_port "9125"
+	config_get statsd_udp_ipv6 main statsd_udp_ipv6 "0"
+	config_get statsd_tcp_interface main statsd_tcp_interface "loopback"
+	config_get statsd_tcp_port main statsd_tcp_port "9125"
+	config_get statsd_tcp_ipv6 main statsd_tcp_ipv6 "0"
 	config_get statsd_mapping_config main statsd_mapping_config "$CONFFILE"
 
+	if [ "$web_ipv6" = 1 ]; then
+		network_get_ipaddr6 web_ip "$web_interface"
+	else
+		network_get_ipaddr web_ip "$web_interface"
+	fi
+
+	network_is_up "$web_interface" && [ -n "$web_ip" ] || {
+		_log "defering start until web interface $web_interface becomes ready"
+		return 0
+	}
+
+	if [ "$statsd_udp_ipv6" = 1 ]; then
+		network_get_ipaddr6 statsd_udp_ip "$statsd_udp_interface"
+	else
+		network_get_ipaddr statsd_udp_ip "$statsd_udp_interface"
+	fi
+
+	network_is_up "$statsd_udp_interface" && [ -n "$statsd_udp_ip" ] || {
+		_log "defering start until statsd udp interface $statsd_udp_interface becomes ready"
+		return 0
+	}
+
+	if [ "$statsd_tcp_ipv6" = 1 ]; then
+		network_get_ipaddr6 statsd_tcp_ip "$statsd_tcp_interface"
+	else
+		network_get_ipaddr statsd_tcp_ip "$statsd_tcp_interface"
+	fi
+
+	network_is_up "$statsd_tcp_interface" && [ -n "$statsd_tcp_ip" ] || {
+		_log "defering start until statsd tcp interface $statsd_tcp_interface becomes ready"
+		return 0
+	}
+
 	procd_open_instance
 	procd_set_param command "$PROG"
-	procd_append_param command --web.listen-address="$web_listen_address"
+	procd_append_param command --web.listen-address="${web_ip}:${web_port}"
 	procd_append_param command --web.telemetry-path="$web_telemetry_path"
-	procd_append_param command --statsd.listen-udp="$statsd_listen_udp"
-	procd_append_param command --statsd.listen-tcp="$statsd_listen_tcp"
+	procd_append_param command --statsd.listen-udp="${statsd_udp_ip}:${statsd_udp_port}"
+	procd_append_param command --statsd.listen-tcp="${statsd_tcp_ip}:${statsd_tcp_port}"
 	procd_append_param command --statsd.mapping-config="$statsd_mapping_config"
 	procd_append_param command --log.level="warn"
+
 	procd_set_param file "$config_file"
 	procd_set_param stdout 1
 	procd_set_param stderr 1
 	procd_set_param respawn
 	procd_close_instance
 }
+
+service_triggers()
+{
+	local web_interface statsd_udp_interface statsd_tcp_interface
+
+	config_load "prometheus-statsd-exporter"
+	config_get web_interface main web_interface "loopback"
+	config_get statsd_udp_interface main statsd_udp_interface "loopback"
+	config_get statsd_tcp_interface main statsd_tcp_interface "loopback"
+
+	procd_add_reload_interface_trigger "$web_interface"
+	procd_add_reload_interface_trigger "$statsd_udp_interface"
+	procd_add_reload_interface_trigger "$statsd_tcp_interface"
+}