statsd_exporter/main.go
Nic Cope fcc398a032 Switch to kingpin for flag handling
This commit also removs the deprecated -statsd.listen-address flag. Switching
to kingpin is a breaking change in that flags now start with two hyphens (e.g.
--statsd.listen-udp), and thus a good time to remove deprecated flags.

Signed-off-by: Nic Cope <negz@planet.com>
2018-08-20 13:18:59 -07:00

190 lines
5.7 KiB
Go

// Copyright 2013 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"net"
"net/http"
"strconv"
"github.com/howeyc/fsnotify"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/log"
"github.com/prometheus/common/version"
"gopkg.in/alecthomas/kingpin.v2"
"github.com/prometheus/statsd_exporter/pkg/mapper"
)
func init() {
prometheus.MustRegister(version.NewCollector("statsd_exporter"))
}
func serveHTTP(listenAddress, metricsEndpoint string) {
http.Handle(metricsEndpoint, prometheus.Handler())
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte(`<html>
<head><title>StatsD Exporter</title></head>
<body>
<h1>StatsD Exporter</h1>
<p><a href="` + metricsEndpoint + `">Metrics</a></p>
</body>
</html>`))
})
log.Fatal(http.ListenAndServe(listenAddress, nil))
}
func ipPortFromString(addr string) (*net.IPAddr, int) {
host, portStr, err := net.SplitHostPort(addr)
if err != nil {
log.Fatal("Bad StatsD listening address", addr)
}
if host == "" {
host = "0.0.0.0"
}
ip, err := net.ResolveIPAddr("ip", host)
if err != nil {
log.Fatalf("Unable to resolve %s: %s", host, err)
}
port, err := strconv.Atoi(portStr)
if err != nil || port < 0 || port > 65535 {
log.Fatalf("Bad port %s: %s", portStr, err)
}
return ip, port
}
func udpAddrFromString(addr string) *net.UDPAddr {
ip, port := ipPortFromString(addr)
return &net.UDPAddr{
IP: ip.IP,
Port: port,
Zone: ip.Zone,
}
}
func tcpAddrFromString(addr string) *net.TCPAddr {
ip, port := ipPortFromString(addr)
return &net.TCPAddr{
IP: ip.IP,
Port: port,
Zone: ip.Zone,
}
}
func watchConfig(fileName string, mapper *mapper.MetricMapper) {
watcher, err := fsnotify.NewWatcher()
if err != nil {
log.Fatal(err)
}
err = watcher.WatchFlags(fileName, fsnotify.FSN_MODIFY)
if err != nil {
log.Fatal(err)
}
for {
select {
case ev := <-watcher.Event:
log.Infof("Config file changed (%s), attempting reload", ev)
err = mapper.InitFromFile(fileName)
if err != nil {
log.Errorln("Error reloading config:", err)
configLoads.WithLabelValues("failure").Inc()
} else {
log.Infoln("Config reloaded successfully")
configLoads.WithLabelValues("success").Inc()
}
// Re-add the file watcher since it can get lost on some changes. E.g.
// saving a file with vim results in a RENAME-MODIFY-DELETE event
// sequence, after which the newly written file is no longer watched.
_ = watcher.WatchFlags(fileName, fsnotify.FSN_MODIFY)
case err := <-watcher.Error:
log.Errorln("Error watching config:", err)
}
}
}
func main() {
var (
listenAddress = kingpin.Flag("web.listen-address", "The address on which to expose the web interface and generated Prometheus metrics.").Default(":9102").String()
metricsEndpoint = kingpin.Flag("web.telemetry-path", "Path under which to expose metrics.").Default("/metrics").String()
statsdListenUDP = kingpin.Flag("statsd.listen-udp", "The UDP address on which to receive statsd metric lines. \"\" disables it.").Default(":9125").String()
statsdListenTCP = kingpin.Flag("statsd.listen-tcp", "The TCP address on which to receive statsd metric lines. \"\" disables it.").Default(":9125").String()
mappingConfig = kingpin.Flag("statsd.mapping-config", "Metric mapping configuration file name.").String()
readBuffer = kingpin.Flag("statsd.read-buffer", "Size (in bytes) of the operating system's transmit read buffer associated with the UDP connection. Please make sure the kernel parameters net.core.rmem_max is set to a value greater than the value specified.").Int()
)
log.AddFlags(kingpin.CommandLine)
kingpin.Version(version.Print("statsd_exporter"))
kingpin.HelpFlag.Short('h')
kingpin.Parse()
if *statsdListenUDP == "" && *statsdListenTCP == "" {
log.Fatalln("At least one of UDP/TCP listeners must be specified.")
}
log.Infoln("Starting StatsD -> Prometheus Exporter", version.Info())
log.Infoln("Build context", version.BuildContext())
log.Infof("Accepting StatsD Traffic: UDP %v, TCP %v", *statsdListenUDP, *statsdListenTCP)
log.Infoln("Accepting Prometheus Requests on", *listenAddress)
go serveHTTP(*listenAddress, *metricsEndpoint)
events := make(chan Events, 1024)
defer close(events)
if *statsdListenUDP != "" {
udpListenAddr := udpAddrFromString(*statsdListenUDP)
uconn, err := net.ListenUDP("udp", udpListenAddr)
if err != nil {
log.Fatal(err)
}
if *readBuffer != 0 {
err = uconn.SetReadBuffer(*readBuffer)
if err != nil {
log.Fatal("Error setting UDP read buffer:", err)
}
}
ul := &StatsDUDPListener{conn: uconn}
go ul.Listen(events)
}
if *statsdListenTCP != "" {
tcpListenAddr := tcpAddrFromString(*statsdListenTCP)
tconn, err := net.ListenTCP("tcp", tcpListenAddr)
if err != nil {
log.Fatal(err)
}
defer tconn.Close()
tl := &StatsDTCPListener{conn: tconn}
go tl.Listen(events)
}
mapper := &mapper.MetricMapper{MappingsCount: mappingsCount}
if *mappingConfig != "" {
err := mapper.InitFromFile(*mappingConfig)
if err != nil {
log.Fatal("Error loading config:", err)
}
go watchConfig(*mappingConfig, mapper)
}
exporter := NewExporter(mapper)
exporter.Listen(events)
}