package main import ( "encoding/json" "flag" "fmt" "io/ioutil" "net/http" _ "net/http/pprof" "os" "os/signal" "strings" "sync" "syscall" "time" "github.com/golang/glog" "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/node_exporter/collector" ) const subsystem = "exporter" var ( // set at build time Version = "0.0.0.dev" configFile = flag.String("config.file", "", "Path to config file.") memProfile = flag.String("debug.memprofile-file", "", "Write memory profile to this file upon receipt of SIGUSR1.") listenAddress = flag.String("web.listen-address", ":9100", "Address on which to expose metrics and web interface.") metricsPath = flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics.") enabledCollectors = flag.String("collectors.enabled", "attributes,diskstats,filesystem,loadavg,meminfo,stat,textfile,time,netdev,netstat", "Comma-separated list of collectors to use.") printCollectors = flag.Bool("collectors.print", false, "If true, print available collectors and exit.") authUser = flag.String("auth.user", "", "Username for basic auth.") authPass = flag.String("auth.pass", "", "Password for basic auth.") collectorLabelNames = []string{"collector", "result"} scrapeDurations = prometheus.NewSummaryVec( prometheus.SummaryOpts{ Namespace: collector.Namespace, Subsystem: subsystem, Name: "scrape_duration_seconds", Help: "node_exporter: Duration of a scrape job.", }, collectorLabelNames, ) ) // Implements Collector. type NodeCollector struct { collectors map[string]collector.Collector } // Implements Collector. func (n NodeCollector) Describe(ch chan<- *prometheus.Desc) { scrapeDurations.Describe(ch) } // Implements Collector. func (n NodeCollector) Collect(ch chan<- prometheus.Metric) { wg := sync.WaitGroup{} wg.Add(len(n.collectors)) for name, c := range n.collectors { go func(name string, c collector.Collector) { Execute(name, c, ch) wg.Done() }(name, c) } wg.Wait() scrapeDurations.Collect(ch) } type basicAuthHandler struct { handler http.HandlerFunc user string password string } func (h *basicAuthHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { user, password, ok := r.BasicAuth() if !ok || password != h.password || user != h.user { w.Header().Set("WWW-Authenticate", "Basic realm=\"metrics\"") http.Error(w, "Invalid username or password", http.StatusUnauthorized) return } h.handler(w, r) return } func Execute(name string, c collector.Collector, ch chan<- prometheus.Metric) { begin := time.Now() err := c.Update(ch) duration := time.Since(begin) var result string if err != nil { glog.Infof("ERROR: %s failed after %fs: %s", name, duration.Seconds(), err) result = "error" } else { glog.Infof("OK: %s success after %fs.", name, duration.Seconds()) result = "success" } scrapeDurations.WithLabelValues(name, result).Observe(duration.Seconds()) } func getConfig(file string) (*collector.Config, error) { config := &collector.Config{} glog.Infof("Reading config %s", *configFile) bytes, err := ioutil.ReadFile(*configFile) if err != nil { return nil, err } return config, json.Unmarshal(bytes, &config) } func loadCollectors(file string) (map[string]collector.Collector, error) { collectors := map[string]collector.Collector{} config := &collector.Config{} if file != "" { var err error config, err = getConfig(file) if err != nil { return nil, fmt.Errorf("couldn't read config %s: %s", file, err) } } for _, name := range strings.Split(*enabledCollectors, ",") { fn, ok := collector.Factories[name] if !ok { return nil, fmt.Errorf("collector '%s' not available", name) } c, err := fn(*config) if err != nil { return nil, err } collectors[name] = c } return collectors, nil } func main() { flag.Parse() if *printCollectors { fmt.Printf("Available collectors:\n") for n, _ := range collector.Factories { fmt.Printf(" - %s\n", n) } return } collectors, err := loadCollectors(*configFile) if err != nil { glog.Fatalf("Couldn't load config and collectors: %s", err) } glog.Infof("Enabled collectors:") for n, _ := range collectors { glog.Infof(" - %s", n) } nodeCollector := NodeCollector{collectors: collectors} prometheus.MustRegister(nodeCollector) sigUsr1 := make(chan os.Signal) signal.Notify(sigUsr1, syscall.SIGUSR1) handler := prometheus.Handler() if *authUser != "" || *authPass != "" { if *authUser == "" || *authPass == "" { glog.Fatal("You need to specify -auth.user and -auth.pass to enable basic auth") } handler = &basicAuthHandler{ handler: prometheus.Handler().ServeHTTP, user: *authUser, password: *authPass, } } http.Handle(*metricsPath, handler) http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) { w.Write([]byte(` Node Exporter

Node Exporter

Metrics

`)) }) glog.Infof("Starting node_exporter v%s at %s", Version, *listenAddress) err = http.ListenAndServe(*listenAddress, nil) if err != nil { glog.Fatal(err) } }