support dynamic change log level through http (#18430)

Signed-off-by: Wei Liu <wei.liu@zilliz.com>

internal/log/log.go

@@ -31,6 +31,7 @@ package log
 
 import (
 	"fmt"
+	"net/http"
 	"os"
 	"sync/atomic"
 
@@ -55,6 +56,12 @@ func init() {
 
 	r := utils.NewRateLimiter(1.0, 60.0)
 	_globalR.Store(r)
+
+	updateLoglLevel := func(w http.ResponseWriter, req *http.Request) {
+		_globalP.Load().(*ZapProperties).Level.ServeHTTP(w, req)
+	}
+
+	http.HandleFunc("/log/level", updateLoglLevel)
 }
 
 // InitLogger initializes a zap logger.

internal/log/log_test.go

@@ -33,7 +33,11 @@ package log
 import (
 	"bufio"
 	"bytes"
+	"context"
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
+	"net/http"
 	"testing"
 	"time"
 
@@ -113,6 +117,56 @@ func TestLevelGetterAndSetter(t *testing.T) {
 	assert.Equal(t, zap.ErrorLevel, GetLevel())
 }
 
+func TestUpdateLogLevelThroughHttp(t *testing.T) {
+	httpServer := &http.Server{Addr: ":9081"}
+	go func() {
+		if err := httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			Fatal(err.Error())
+		}
+	}()
+
+	SetLevel(zap.DebugLevel)
+	assert.Equal(t, zap.DebugLevel, GetLevel())
+
+	// replace global logger, log change will not be affected.
+	conf := &Config{Level: "info", File: FileLogConfig{}, DisableTimestamp: true}
+	logger, p, _ := InitLogger(conf)
+	ReplaceGlobals(logger, p)
+	assert.Equal(t, zap.InfoLevel, GetLevel())
+
+	// change log level through http
+	payload, err := json.Marshal(map[string]interface{}{"level": "error"})
+	if err != nil {
+		Fatal(err.Error())
+	}
+
+	req, err := http.NewRequest(http.MethodPut, "http://localhost:9081/log/level", bytes.NewBuffer(payload))
+	req.Header.Set("Content-Type", "application/json")
+	if err != nil {
+		Fatal(err.Error())
+	}
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		Fatal(err.Error())
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		Fatal(err.Error())
+	}
+	assert.Equal(t, "{\"level\":\"error\"}\n", string(body))
+	assert.Equal(t, zap.ErrorLevel, GetLevel())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	if err := httpServer.Shutdown(ctx); err != nil {
+		Fatal(err.Error())
+	}
+}
+
 func TestSampling(t *testing.T) {
 	sample, drop := make(chan zapcore.SamplingDecision, 1), make(chan zapcore.SamplingDecision, 1)
 	samplingConf := zap.SamplingConfig{