use logger.LogOnce to reduce printing disconnection logs (#15408)

fixes #15334

- re-use net/url parsed value for http.Request{}
- remove gosimple, structcheck and unusued due to https://github.com/golangci/golangci-lint/issues/2649
- unwrapErrs upto leafErr to ensure that we store exactly the correct errors

internal/event/target/redis.go

@@ -30,6 +30,7 @@ import (
 
 	"github.com/gomodule/redigo/redis"
 	"github.com/minio/minio/internal/event"
+	"github.com/minio/minio/internal/logger"
 	xnet "github.com/minio/pkg/net"
 )
 
@@ -121,7 +122,7 @@ type RedisTarget struct {
 	pool       *redis.Pool
 	store      Store
 	firstPing  bool
-	loggerOnce func(ctx context.Context, err error, id interface{}, errKind ...interface{})
+	loggerOnce logger.LogOnce
 }
 
 // ID - returns target ID.
@@ -137,10 +138,8 @@ func (target *RedisTarget) HasQueueStore() bool {
 // IsActive - Return true if target is up and active
 func (target *RedisTarget) IsActive() (bool, error) {
 	conn := target.pool.Get()
-	defer func() {
-		cErr := conn.Close()
-		target.loggerOnce(context.Background(), cErr, target.ID())
-	}()
+	defer conn.Close()
+
 	_, pingErr := conn.Do("PING")
 	if pingErr != nil {
 		if IsConnRefusedErr(pingErr) {
@@ -166,10 +165,7 @@ func (target *RedisTarget) Save(eventData event.Event) error {
 // send - sends an event to the redis.
 func (target *RedisTarget) send(eventData event.Event) error {
 	conn := target.pool.Get()
-	defer func() {
-		cErr := conn.Close()
-		target.loggerOnce(context.Background(), cErr, target.ID())
-	}()
+	defer conn.Close()
 
 	if target.args.Format == event.NamespaceFormat {
 		objectName, err := url.QueryUnescape(eventData.S3.Object.Key)
@@ -209,10 +205,8 @@ func (target *RedisTarget) send(eventData event.Event) error {
 // Send - reads an event from store and sends it to redis.
 func (target *RedisTarget) Send(eventKey string) error {
 	conn := target.pool.Get()
-	defer func() {
-		cErr := conn.Close()
-		target.loggerOnce(context.Background(), cErr, target.ID())
-	}()
+	defer conn.Close()
+
 	_, pingErr := conn.Do("PING")
 	if pingErr != nil {
 		if IsConnRefusedErr(pingErr) {
@@ -258,7 +252,7 @@ func (target *RedisTarget) Close() error {
 }
 
 // NewRedisTarget - creates new Redis target.
-func NewRedisTarget(id string, args RedisArgs, doneCh <-chan struct{}, loggerOnce func(ctx context.Context, err error, id interface{}, errKind ...interface{}), test bool) (*RedisTarget, error) {
+func NewRedisTarget(id string, args RedisArgs, doneCh <-chan struct{}, loggerOnce logger.LogOnce, test bool) (*RedisTarget, error) {
 	pool := &redis.Pool{
 		MaxIdle:     3,
 		IdleTimeout: 2 * 60 * time.Second,
@@ -270,18 +264,14 @@ func NewRedisTarget(id string, args RedisArgs, doneCh <-chan struct{}, loggerOnc
 
 			if args.Password != "" {
 				if _, err = conn.Do("AUTH", args.Password); err != nil {
-					cErr := conn.Close()
-					targetID := event.TargetID{ID: id, Name: "redis"}
-					loggerOnce(context.Background(), cErr, targetID)
+					conn.Close()
 					return nil, err
 				}
 			}
 
 			// Must be done after AUTH
 			if _, err = conn.Do("CLIENT", "SETNAME", "MinIO"); err != nil {
-				cErr := conn.Close()
-				targetID := event.TargetID{ID: id, Name: "redis"}
-				loggerOnce(context.Background(), cErr, targetID)
+				conn.Close()
 				return nil, err
 			}
 
@@ -306,27 +296,24 @@ func NewRedisTarget(id string, args RedisArgs, doneCh <-chan struct{}, loggerOnc
 		queueDir := filepath.Join(args.QueueDir, storePrefix+"-redis-"+id)
 		store = NewQueueStore(queueDir, args.QueueLimit)
 		if oErr := store.Open(); oErr != nil {
-			target.loggerOnce(context.Background(), oErr, target.ID())
+			target.loggerOnce(context.Background(), oErr, target.ID().String())
 			return target, oErr
 		}
 		target.store = store
 	}
 
 	conn := target.pool.Get()
-	defer func() {
-		cErr := conn.Close()
-		target.loggerOnce(context.Background(), cErr, target.ID())
-	}()
+	defer conn.Close()
 
 	_, pingErr := conn.Do("PING")
 	if pingErr != nil {
 		if target.store == nil || !(IsConnRefusedErr(pingErr) || IsConnResetErr(pingErr)) {
-			target.loggerOnce(context.Background(), pingErr, target.ID())
+			target.loggerOnce(context.Background(), pingErr, target.ID().String())
 			return target, pingErr
 		}
 	} else {
 		if err := target.args.validateFormat(conn); err != nil {
-			target.loggerOnce(context.Background(), err, target.ID())
+			target.loggerOnce(context.Background(), err, target.ID().String())
 			return target, err
 		}
 		target.firstPing = true