Add error filter to admin trace API (#7923)

This allows MinIO to have the ability to send back only error trace

pkg/madmin/api-trace.go

@@ -32,7 +32,7 @@ type TraceInfo struct {
 }
 
 // Trace - listen on http trace notifications.
-func (adm AdminClient) Trace(allTrace bool, doneCh <-chan struct{}) <-chan TraceInfo {
+func (adm AdminClient) Trace(allTrace, errTrace bool, doneCh <-chan struct{}) <-chan TraceInfo {
 	traceInfoCh := make(chan TraceInfo)
 	// Only success, start a routine to start reading line by line.
 	go func(traceInfoCh chan<- TraceInfo) {
@@ -40,6 +40,7 @@ func (adm AdminClient) Trace(allTrace bool, doneCh <-chan struct{}) <-chan Trace
 		for {
 			urlValues := make(url.Values)
 			urlValues.Set("all", strconv.FormatBool(allTrace))
+			urlValues.Set("err", strconv.FormatBool(errTrace))
 			reqData := requestData{
 				relPath:     "/v1/trace",
 				queryValues: urlValues,

pkg/madmin/examples/trace.go

@@ -20,6 +20,7 @@
 package main
 
 import (
+	"fmt"
 	"log"
 
 	"github.com/minio/minio/pkg/madmin"
@@ -40,7 +41,9 @@ func main() {
 
 	// Start listening on all http trace activity from all servers
 	// in the minio cluster.
-	traceCh := madmClnt.Trace(false, doneCh)
+	allTrace := false
+	errTrace := false
+	traceCh := madmClnt.Trace(allTrace, errTrace, doneCh)
 	for traceInfo := range traceCh {
 		if traceInfo.Err != nil {
 			fmt.Println(traceInfo.Err)