// 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 (
"flag"
"net"
"net/http"
"strconv"
"github.com/howeyc/fsnotify"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/log"
)
var (
listenAddress = flag.String("web.listen-address", ":9102", "The address on which to expose the web interface and generated Prometheus metrics.")
metricsEndpoint = flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics.")
statsdListenAddress = flag.String("statsd.listen-address", ":9125", "The UDP address on which to receive statsd metric lines.")
mappingConfig = flag.String("statsd.mapping-config", "", "Metric mapping configuration file name.")
readBuffer = flag.Int("statsd.read-buffer", 0, "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.")
)
func serveHTTP() {
http.Handle(*metricsEndpoint, prometheus.Handler())
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte(`
StatsD Bridge
StatsD Bridge
Metrics
`))
})
http.ListenAndServe(*listenAddress, nil)
}
func udpAddrFromString(addr string) *net.UDPAddr {
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 &net.UDPAddr{
IP: ip.IP,
Port: port,
Zone: ip.Zone,
}
}
func watchConfig(fileName string, 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.Printf("Config file changed (%s), attempting reload", ev)
err = mapper.initFromFile(fileName)
if err != nil {
log.Println("Error reloading config:", err)
configLoads.WithLabelValues("failure").Inc()
} else {
log.Println("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.
err = watcher.WatchFlags(fileName, fsnotify.FSN_MODIFY)
case err := <-watcher.Error:
log.Println("Error watching config:", err)
}
}
}
func main() {
flag.Parse()
log.Println("Starting StatsD -> Prometheus Exporter...")
log.Println("Accepting StatsD Traffic on", *statsdListenAddress)
log.Println("Accepting Prometheus Requests on", *listenAddress)
go serveHTTP()
events := make(chan Events, 1024)
defer close(events)
listenAddr := udpAddrFromString(*statsdListenAddress)
conn, err := net.ListenUDP("udp", listenAddr)
if err != nil {
log.Fatal(err)
}
if *readBuffer != 0 {
err = conn.SetReadBuffer(*readBuffer)
if err != nil {
log.Fatal("Error setting UDP read buffer:", err)
}
}
l := &StatsDListener{conn: conn}
go l.Listen(events)
mapper := &metricMapper{}
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)
}