Initial commit

metric/exporter.go

@@ -0,0 +1,113 @@
+package metric
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"os"
+	"strconv"
+	"time"
+
+	consulapi "github.com/hashicorp/consul/api"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"globalfintech/golib/tlog"
+)
+
+const (
+	DefaultListenerAddr = "0.0.0.0:9166"
+)
+
+type ExporterCfg struct {
+	Listener       net.Listener
+	RegisterConsul bool
+	ProductName    string
+	ServiceRegion  string
+	AppName        string
+}
+
+// Exporter init function must be executed asynchronously
+func InitExporter(cfg ExporterCfg) (err error) {
+	lis := cfg.Listener
+	if cfg.Listener == nil {
+		if lis, err = net.Listen("tcp", DefaultListenerAddr); err != nil {
+			tlog.Error("fail to create listener with default address")
+			return err
+		}
+	}
+
+	_, port, err := net.SplitHostPort(lis.Addr().String())
+	if err != nil {
+		tlog.Error("fail to get port from listener, err: ", err)
+		return err
+	}
+
+	h := http.NewServeMux()
+	h.Handle("/metrics", promhttp.Handler())
+	h.HandleFunc("/health_checker", healthChecker)
+	server := &http.Server{
+		Handler:           h,
+		ReadTimeout:       30 * time.Second,
+		ReadHeaderTimeout: 30 * time.Second,
+		IdleTimeout:       30 * time.Second,
+		WriteTimeout:      10 * time.Second,
+	}
+
+	if cfg.RegisterConsul {
+		var tags []string
+		tags = append(tags, fmt.Sprintf("app=%s", cfg.ProductName))
+		tags = append(tags, fmt.Sprintf("country=%s", cfg.ServiceRegion))
+		err = consulRegister(port, "", tags, cfg.AppName)
+		if err != nil {
+			tlog.Error("consul register failed, err: ", err)
+			return err
+		}
+	}
+
+	if err = server.Serve(lis); err != nil {
+		tlog.Error("fail to init prometheus exporter, err: ", err)
+		return err
+	}
+
+	return nil
+}
+
+func consulRegister(checkPort string, regAddr string, tags []string, name string) (err error) {
+	config := consulapi.DefaultConfig()
+	if regAddr != "" {
+		config.Address = regAddr
+	}
+
+	client, err := consulapi.NewClient(config)
+	if err != nil {
+		tlog.Error("fail to new consul client, err: ", err)
+		return err
+	}
+
+	intPort, _ := strconv.Atoi(checkPort)
+	hostName, _ := os.Hostname()
+
+	registration := &consulapi.AgentServiceRegistration{
+		Port: intPort,
+		Name: name,
+		ID:   name + ":" + hostName,
+		Tags: append(tags, "lang=go"),
+		Check: &consulapi.AgentServiceCheck{
+			HTTP:     fmt.Sprintf("http://%s:%s%s", "127.0.0.1", checkPort, "/health_checker"),
+			Interval: "10s",
+			Timeout:  "10s",
+		},
+	}
+
+	return client.Agent().ServiceRegister(registration)
+}
+
+func healthChecker(resp http.ResponseWriter, req *http.Request) {
+	data := map[string]interface{}{
+		"code":        0,
+		"message":     "ok",
+		"server_time": time.Now().Unix(),
+	}
+	res, _ := json.Marshal(data)
+	resp.Write(res)
+}