From a6e8bcb1c412fdf68cb7c0b109ffe943f202356e Mon Sep 17 00:00:00 2001 From: Johannes 'fish' Ziemke Date: Thu, 18 Apr 2013 16:45:37 +0200 Subject: [PATCH] Exporter exposing load, last login and tag list. The list of tags can be configured in a json config. --- .gitignore | 1 + node_exporter.conf | 7 ++ node_exporter.go | 224 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 232 insertions(+) create mode 100644 node_exporter.conf create mode 100644 node_exporter.go diff --git a/.gitignore b/.gitignore index 00268614..583259c0 100644 --- a/.gitignore +++ b/.gitignore @@ -20,3 +20,4 @@ _cgo_export.* _testmain.go *.exe +node_exporter diff --git a/node_exporter.conf b/node_exporter.conf new file mode 100644 index 00000000..6800bac1 --- /dev/null +++ b/node_exporter.conf @@ -0,0 +1,7 @@ +{ + "attributes" : { + "web-server" : "1", + "zone" : "a", + "default" : "1" + } +} diff --git a/node_exporter.go b/node_exporter.go new file mode 100644 index 00000000..38194a05 --- /dev/null +++ b/node_exporter.go @@ -0,0 +1,224 @@ +package main + +import ( + "bufio" + "encoding/json" + "flag" + "fmt" + "github.com/prometheus/client_golang" + "github.com/prometheus/client_golang/metrics" + "io" + "io/ioutil" + "log" + "net/http" + _ "net/http/pprof" + "os" + "os/exec" + "os/signal" + "strconv" + "strings" + "syscall" + "time" +) + +const ( + proto = "tcp" + procLoad = "/proc/loadavg" +) + +var ( + verbose = flag.Bool("verbose", false, "Verbose output.") + listeningAddress = flag.String("listeningAddress", ":8080", "Address on which to expose JSON metrics.") + metricsEndpoint = flag.String("metricsEndpoint", "/metrics.json", "Path under which to expose JSON metrics.") + configFile = flag.String("config", "node_exporter.conf", "Config file.") + scrapeInterval = flag.Int("interval", 60, "Scrape interval.") + + loadAvg = metrics.NewGauge() + attributes = metrics.NewGauge() + lastSeen = metrics.NewGauge() +) + +type config struct { + Attributes map[string]string `json:"attributes"` +} + +func init() { + hostname, err := os.Hostname() + if err != nil { + log.Fatalf("Couldn't get hostname: %s", err) + } + + registry.DefaultRegistry.Register( + "node_load", + "node_exporter: system load.", + map[string]string{"hostname": hostname}, + loadAvg, + ) + + registry.DefaultRegistry.Register( + "node_last_login_seconds", + "node_exporter: seconds since last login.", + map[string]string{"hostname": hostname}, + lastSeen, + ) + + registry.DefaultRegistry.Register( + "node_attributes", + "node_exporter: system attributes.", + map[string]string{"hostname": hostname}, + attributes, + ) +} + +func debug(format string, a ...interface{}) { + if *verbose { + log.Printf(format, a...) + } +} + +func newConfig(filename string) (conf config, err error) { + log.Printf("Reading config %s", filename) + bytes, err := ioutil.ReadFile(filename) + if err != nil { + return + } + + err = json.Unmarshal(bytes, &conf) + return +} + +func serveStatus() { + exporter := registry.DefaultRegistry.Handler() + + http.Handle(*metricsEndpoint, exporter) + http.ListenAndServe(*listeningAddress, nil) +} + +// Takes a string, splits it, converts each element to int and returns them as new list. +// It will return an error in case any element isn't an int. +func splitToInts(str string, sep string) (ints []int, err error) { + for _, part := range strings.Split(str, sep) { + i, err := strconv.Atoi(part) + if err != nil { + return nil, fmt.Errorf("Could not split '%s' because %s is no int: %s", str, part, err) + } + ints = append(ints, i) + } + return ints, nil +} + +func main() { + flag.Parse() + sig := make(chan os.Signal, 1) + signal.Notify(sig, syscall.SIGHUP) + configChan := make(chan config) + go func() { + for _ = range sig { + config, err := newConfig(*configFile) + if err != nil { + log.Printf("Couldn't reload config: %s", err) + continue + } + configChan <- config + } + }() + + conf, err := newConfig(*configFile) + if err != nil { + log.Fatalf("Couldn't read config: %s", err) + } + + go serveStatus() + + tick := time.Tick(time.Duration(*scrapeInterval) * time.Second) + for { + select { + case conf = <-configChan: + log.Printf("Got new config") + case <-tick: + log.Printf("Starting new scrape interval") + + last, err := getSecondsSinceLastLogin() + if err != nil { + log.Printf("Couldn't get last seen: %s", err) + } else { + debug("last: %f", last) + lastSeen.Set(nil, last) + } + + load, err := getLoad() + if err != nil { + log.Printf("Couldn't get load: %s", err) + } else { + debug("load: %f", load) + loadAvg.Set(nil, load) + } + + debug("attributes: %s", conf.Attributes) + attributes.Set(conf.Attributes, 1) + + } + } +} + +func getLoad() (float64, error) { + data, err := ioutil.ReadFile(procLoad) + if err != nil { + return 0, err + } + parts := strings.Fields(string(data)) + load, err := strconv.ParseFloat(parts[0], 64) + if err != nil { + return 0, fmt.Errorf("Could not parse load '%s': %s", parts[0], err) + } + return load, nil +} + +func getSecondsSinceLastLogin() (float64, error) { + who := exec.Command("who", "/var/log/wtmp", "-l", "-u", "-s") + + output, err := who.StdoutPipe() + if err != nil { + return 0, err + } + + err = who.Start() + if err != nil { + return 0, err + } + + reader := bufio.NewReader(output) + var last time.Time + for { + line, isPrefix, err := reader.ReadLine() + if err == io.EOF { + break + } + if isPrefix { + return 0, fmt.Errorf("line to long: %s(...)", line) + } + + fields := strings.Fields(string(line)) + lastDate := fields[2] + lastTime := fields[3] + + dateParts, err := splitToInts(lastDate, "-") // 2013-04-16 + if err != nil { + return 0, err + } + + timeParts, err := splitToInts(lastTime, ":") // 11:33 + if err != nil { + return 0, err + } + + last_t := time.Date(dateParts[0], time.Month(dateParts[1]), dateParts[2], timeParts[0], timeParts[1], 0, 0, time.UTC) + last = last_t + } + err = who.Wait() + if err != nil { + return 0, err + } + + return float64(time.Now().Sub(last).Seconds()), nil +}