vendor update for E2E framework

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/k8s.io/utils/io/read.go

@@ -18,10 +18,15 @@ package io
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 )
 
+// ErrLimitReached means that the read limit is reached.
+var ErrLimitReached = errors.New("the read limit is reached")
+
 // ConsistentRead repeatedly reads a file until it gets the same content twice.
 // This is useful when reading files in /proc that are larger than page size
 // and kernel may modify them between individual read() syscalls.
@@ -53,3 +58,17 @@ func consistentReadSync(filename string, attempts int, sync func(int)) ([]byte,
 	}
 	return nil, fmt.Errorf("could not get consistent content of %s after %d attempts", filename, attempts)
 }
+
+// ReadAtMost reads up to `limit` bytes from `r`, and reports an error
+// when `limit` bytes are read.
+func ReadAtMost(r io.Reader, limit int64) ([]byte, error) {
+	limitedReader := &io.LimitedReader{R: r, N: limit}
+	data, err := ioutil.ReadAll(limitedReader)
+	if err != nil {
+		return data, err
+	}
+	if limitedReader.N <= 0 {
+		return data, ErrLimitReached
+	}
+	return data, nil
+}