Use errors.Is instead of checking underlying err messages (#5140)

* Use errors.Is instead of checking underlying err messages

Fixes #5132

This PR replaces the usage of `strings.hasSuffix` with `errors.Is`
wherever error messages are being checked. So, that the code is not
effected by changes in the underlying message. Also adds a string
const for http2 response body closed error

Signed-off-by: Tarun Pothulapati <tarunpothulapati@outlook.com>

cli/cmd/top.go

@@ -435,7 +435,7 @@ func recvEvents(tapByteStream *bufio.Reader, eventCh chan<- *pb.TapEvent, closin
 		if err != nil {
 			if err == io.EOF {
 				fmt.Println("Tap stream terminated")
-			} else if !strings.HasSuffix(err.Error(), "http2: response body closed") {
+			} else if !strings.HasSuffix(err.Error(), tap.ErrClosedResponseBody) {
 				fmt.Println(err.Error())
 			}
 

pkg/profiles/tap.go

@@ -3,8 +3,10 @@ package profiles
 import (
 	"bufio"
 	"context"
+	"errors"
 	"fmt"
 	"io"
+	"net"
 	"os"
 	"sort"
 	"strings"
@@ -83,10 +85,11 @@ func routeSpecFromTap(tapByteStream *bufio.Reader, routeLimit int) []*sp.RouteSp
 		err := protohttp.FromByteStreamToProtocolBuffers(tapByteStream, &event)
 		if err != nil {
 			// expected errors when hitting the tapDuration deadline
+			var e net.Error
 			if err != io.EOF &&
-				!strings.HasSuffix(err.Error(), "(Client.Timeout or context cancellation while reading body)") &&
-				!strings.HasSuffix(err.Error(), "context deadline exceeded") &&
-				!strings.HasSuffix(err.Error(), "http2: response body closed") {
+				!(errors.As(err, &e) && e.Timeout()) &&
+				!errors.Is(err, context.DeadlineExceeded) &&
+				!strings.HasSuffix(err.Error(), tap.ErrClosedResponseBody) {
 				fmt.Fprintln(os.Stderr, err)
 			}
 			break

pkg/protohttp/protohttp.go

@@ -131,14 +131,14 @@ func deserializePayloadFromReader(reader *bufio.Reader) ([]byte, error) {
 	messageLengthAsBytes := make([]byte, numBytesForMessageLength)
 	_, err := io.ReadFull(reader, messageLengthAsBytes)
 	if err != nil {
-		return nil, fmt.Errorf("error while reading message length: %v", err)
+		return nil, fmt.Errorf("error while reading message length: %w", err)
 	}
 	messageLength := int(binary.LittleEndian.Uint32(messageLengthAsBytes))
 
 	messageContentsAsBytes := make([]byte, messageLength)
 	_, err = io.ReadFull(reader, messageContentsAsBytes)
 	if err != nil {
-		return nil, fmt.Errorf("error while reading bytes from message: %v", err)
+		return nil, fmt.Errorf("error while reading bytes from message: %w", err)
 	}
 
 	return messageContentsAsBytes, nil
@@ -190,12 +190,12 @@ func CheckIfResponseHasError(rsp *http.Response) error {
 func FromByteStreamToProtocolBuffers(byteStreamContainingMessage *bufio.Reader, out proto.Message) error {
 	messageAsBytes, err := deserializePayloadFromReader(byteStreamContainingMessage)
 	if err != nil {
-		return fmt.Errorf("error reading byte stream header: %v", err)
+		return fmt.Errorf("error reading byte stream header: %w", err)
 	}
 
 	err = proto.Unmarshal(messageAsBytes, out)
 	if err != nil {
-		return fmt.Errorf("error unmarshalling array of [%d] bytes error: %v", len(messageAsBytes), err)
+		return fmt.Errorf("error unmarshalling array of [%d] bytes error: %w", len(messageAsBytes), err)
 	}
 
 	return nil

pkg/tap/tap.go

@@ -16,6 +16,11 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+const (
+	// ErrClosedResponseBody is returned when response body is closed in http2
+	ErrClosedResponseBody = "http2: response body closed"
+)
+
 // TapRbacURL is the link users should visit to remedy issues when attempting
 // to tap resources with missing authorizations
 const TapRbacURL = "https://linkerd.io/tap-rbac"