added a rate limited writer for klog (#17)

Author: def

go.mod

@@ -138,7 +138,7 @@ require (
 	golang.org/x/exp v0.0.0-20221106115401-f9659909a136 // indirect
 	golang.org/x/sync v0.1.0 // indirect
 	golang.org/x/text v0.7.0 // indirect
-	golang.org/x/time v0.2.0 // indirect
+	golang.org/x/time v0.3.0 // indirect
 	google.golang.org/genproto v0.0.0-20230110181048-76db0878b65f // indirect
 	google.golang.org/grpc v1.53.0 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect

go.sum

@@ -1211,6 +1211,8 @@ golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxb
 golang.org/x/time v0.0.0-20200630173020-3af7569d3a1e/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.2.0 h1:52I/1L54xyEQAYdtcSuxtiT84KGYTBGXwayxmIpNJhE=
 golang.org/x/time v0.2.0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
+golang.org/x/time v0.3.0 h1:rg5rLMjNzMS1RkNLzCG38eapWhnYLFYXDXj2gOlr8j4=
+golang.org/x/time v0.3.0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20181030221726-6c7e314b6563/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

main.go

@@ -11,6 +11,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"golang.org/x/mod/semver"
 	"golang.org/x/sys/unix"
+	"golang.org/x/time/rate"
 	"k8s.io/klog/v2"
 	"net/http"
 	_ "net/http/pprof"
@@ -74,6 +75,9 @@ func machineID() string {
 }
 
 func main() {
+	klog.LogToStderr(false)
+	klog.SetOutput(&RateLimitedLogOutput{limiter: rate.NewLimiter(10, 100)})
+
 	klog.Infoln("agent version:", version)
 
 	hostname, kv, err := uname()
@@ -128,3 +132,14 @@ type logger struct{}
 func (l logger) Println(v ...interface{}) {
 	klog.Errorln(v...)
 }
+
+type RateLimitedLogOutput struct {
+	limiter *rate.Limiter
+}
+
+func (o *RateLimitedLogOutput) Write(data []byte) (int, error) {
+	if !o.limiter.Allow() {
+		return len(data), nil
+	}
+	return os.Stderr.Write(data)
+}