client: Use func without format

Signed-off-by: Sasha Melentyev <sasha@melentyev.io>

client/pkg/fileutil/lock_windows.go

@@ -54,7 +54,7 @@ func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
 
 func open(path string, flag int, perm os.FileMode) (*os.File, error) {
 	if path == "" {
-		return nil, fmt.Errorf("cannot open empty filename")
+		return nil, errors.New("cannot open empty filename")
 	}
 	var access uint32
 	switch flag {

client/pkg/testutil/leak.go

@@ -48,7 +48,7 @@ func CheckLeakedGoroutine() bool {
 		stackCount[normalized]++
 	}
 
-	fmt.Fprintf(os.Stderr, "Unexpected goroutines running after all test(s).\n")
+	fmt.Fprint(os.Stderr, "Unexpected goroutines running after all test(s).\n")
 	for stack, count := range stackCount {
 		fmt.Fprintf(os.Stderr, "%d instances of:\n%s\n", count, stack)
 	}

client/pkg/transport/keepalive_listener.go

@@ -16,6 +16,7 @@ package transport
 
 import (
 	"crypto/tls"
+	"errors"
 	"fmt"
 	"net"
 	"time"
@@ -38,7 +39,7 @@ func NewKeepAliveListener(l net.Listener, scheme string, tlscfg *tls.Config) (ne
 
 	if scheme == "https" {
 		if tlscfg == nil {
-			return nil, fmt.Errorf("cannot listen on TLS for given listener: KeyFile and CertFile are not presented")
+			return nil, errors.New("cannot listen on TLS for given listener: KeyFile and CertFile are not presented")
 		}
 		return newTLSKeepaliveListener(kal, tlscfg), nil
 	}

client/pkg/transport/listener.go

@@ -200,7 +200,7 @@ func SelfCert(lg *zap.Logger, dirpath string, hosts []string, selfSignedCertVali
 	verify.Assert(lg != nil, "nil log isn't allowed")
 	info.Logger = lg
 	if selfSignedCertValidity == 0 {
-		err = fmt.Errorf("selfSignedCertValidity is invalid,it should be greater than 0")
+		err = errors.New("selfSignedCertValidity is invalid,it should be greater than 0")
 		info.Logger.Warn(
 			"cannot generate cert",
 			zap.Error(err),

client/pkg/transport/sockopt_solaris.go

@@ -18,14 +18,14 @@
 package transport
 
 import (
-	"fmt"
+	"errors"
 	"syscall"
 
 	"golang.org/x/sys/unix"
 )
 
 func setReusePort(network, address string, c syscall.RawConn) error {
-	return fmt.Errorf("port reuse is not supported on Solaris")
+	return errors.New("port reuse is not supported on Solaris")
 }
 
 func setReuseAddress(network, address string, conn syscall.RawConn) error {

client/pkg/transport/sockopt_windows.go

@@ -18,16 +18,16 @@
 package transport
 
 import (
-	"fmt"
+	"errors"
 	"syscall"
 )
 
 func setReusePort(network, address string, c syscall.RawConn) error {
-	return fmt.Errorf("port reuse is not supported on Windows")
+	return errors.New("port reuse is not supported on Windows")
 }
 
 // Windows supports SO_REUSEADDR, but it may cause undefined behavior, as
 // there is no protection against port hijacking.
 func setReuseAddress(network, addr string, conn syscall.RawConn) error {
-	return fmt.Errorf("address reuse is not supported on Windows")
+	return errors.New("address reuse is not supported on Windows")
 }

client/pkg/transport/tls.go

@@ -16,6 +16,7 @@ package transport
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"strings"
 	"time"
@@ -46,7 +47,7 @@ func ValidateSecureEndpoints(tlsInfo TLSInfo, eps []string) ([]string, error) {
 		endpoints = append(endpoints, ep)
 	}
 	if len(errs) != 0 {
-		err = fmt.Errorf("%s", strings.Join(errs, ","))
+		err = errors.New(strings.Join(errs, ","))
 	}
 	return endpoints, err
 }

client/v2/client.go

@@ -649,7 +649,7 @@ func (r *redirectFollowingHTTPClient) Do(ctx context.Context, act httpAction) (*
 		if resp.StatusCode/100 == 3 {
 			hdr := resp.Header.Get("Location")
 			if hdr == "" {
-				return nil, nil, fmt.Errorf("location header not set")
+				return nil, nil, errors.New("location header not set")
 			}
 			loc, err := url.Parse(hdr)
 			if err != nil {

client/v2/client_test.go

@@ -17,7 +17,6 @@ package client
 import (
 	"context"
 	"errors"
-	"fmt"
 	"io"
 	"math/rand"
 	"net/http"
@@ -429,7 +428,7 @@ func TestHTTPClusterClientDo(t *testing.T) {
 				rand: rand.New(rand.NewSource(0)),
 			},
 			ctx:        context.WithValue(context.Background(), &oneShotCtxValue, &oneShotCtxValue),
-			wantErr:    fmt.Errorf("client: etcd member  returns server error [Bad Gateway]"),
+			wantErr:    errors.New("client: etcd member  returns server error [Bad Gateway]"),
 			wantPinned: 1,
 		},
 	}

client/v3/client.go

@@ -410,7 +410,7 @@ func newClient(cfg *Config) (*Client, error) {
 
 	if len(cfg.Endpoints) < 1 {
 		client.cancel()
-		return nil, fmt.Errorf("at least one Endpoint is required in client config")
+		return nil, errors.New("at least one Endpoint is required in client config")
 	}
 	client.SetEndpoints(cfg.Endpoints...)
 

client/v3/client_test.go

@@ -16,7 +16,7 @@ package clientv3
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"io"
 	"net"
 	"sync"
@@ -152,7 +152,7 @@ func TestDialNoTimeout(t *testing.T) {
 }
 
 func TestIsHaltErr(t *testing.T) {
-	if !isHaltErr(context.TODO(), fmt.Errorf("etcdserver: some etcdserver error")) {
+	if !isHaltErr(context.TODO(), errors.New("etcdserver: some etcdserver error")) {
 		t.Errorf(`error prefixed with "etcdserver: " should be Halted by default`)
 	}
 	if isHaltErr(context.TODO(), rpctypes.ErrGRPCStopped) {

client/v3/concurrency/key.go

@@ -16,7 +16,7 @@ package concurrency
 
 import (
 	"context"
-	"fmt"
+	"errors"
 
 	pb "go.etcd.io/etcd/api/v3/etcdserverpb"
 	"go.etcd.io/etcd/api/v3/mvccpb"
@@ -42,7 +42,7 @@ func waitDelete(ctx context.Context, client *v3.Client, key string, rev int64) e
 	if err := ctx.Err(); err != nil {
 		return err
 	}
-	return fmt.Errorf("lost watcher waiting for delete")
+	return errors.New("lost watcher waiting for delete")
 }
 
 // waitDeletes efficiently waits until all keys matching the prefix and no greater

client/v3/logger.go

@@ -52,7 +52,7 @@ func etcdClientDebugLevel() zapcore.Level {
 	}
 	var l zapcore.Level
 	if err := l.Set(envLevel); err != nil {
-		log.Printf("Invalid value for environment variable 'ETCD_CLIENT_DEBUG'. Using default level: 'info'")
+		log.Print("Invalid value for environment variable 'ETCD_CLIENT_DEBUG'. Using default level: 'info'")
 		return zapcore.InfoLevel
 	}
 	return l

client/v3/watch.go

@@ -408,7 +408,7 @@ func (w *watcher) RequestProgress(ctx context.Context) (err error) {
 	w.mu.Lock()
 	if w.streams == nil {
 		w.mu.Unlock()
-		return fmt.Errorf("no stream found for context")
+		return errors.New("no stream found for context")
 	}
 	wgs := w.streams[ctxKey]
 	if wgs == nil {