[VOL-1386]  This commit add "dep" as the package management tool
for voltha-go.

Change-Id: I52bc4911dd00a441756ec7c30f46d45091f3f90e
diff --git a/vendor/github.com/sirupsen/logrus/entry.go b/vendor/github.com/sirupsen/logrus/entry.go
new file mode 100644
index 0000000..df6d188
--- /dev/null
+++ b/vendor/github.com/sirupsen/logrus/entry.go
@@ -0,0 +1,393 @@
+package logrus
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"reflect"
+	"runtime"
+	"strings"
+	"sync"
+	"time"
+)
+
+var (
+	bufferPool *sync.Pool
+
+	// qualified package name, cached at first use
+	logrusPackage string
+
+	// Positions in the call stack when tracing to report the calling method
+	minimumCallerDepth int
+
+	// Used for caller information initialisation
+	callerInitOnce sync.Once
+)
+
+const (
+	maximumCallerDepth int = 25
+	knownLogrusFrames  int = 4
+)
+
+func init() {
+	bufferPool = &sync.Pool{
+		New: func() interface{} {
+			return new(bytes.Buffer)
+		},
+	}
+
+	// start at the bottom of the stack before the package-name cache is primed
+	minimumCallerDepth = 1
+}
+
+// Defines the key when adding errors using WithError.
+var ErrorKey = "error"
+
+// An entry is the final or intermediate Logrus logging entry. It contains all
+// the fields passed with WithField{,s}. It's finally logged when Trace, Debug,
+// Info, Warn, Error, Fatal or Panic is called on it. These objects can be
+// reused and passed around as much as you wish to avoid field duplication.
+type Entry struct {
+	Logger *Logger
+
+	// Contains all the fields set by the user.
+	Data Fields
+
+	// Time at which the log entry was created
+	Time time.Time
+
+	// Level the log entry was logged at: Trace, Debug, Info, Warn, Error, Fatal or Panic
+	// This field will be set on entry firing and the value will be equal to the one in Logger struct field.
+	Level Level
+
+	// Calling method, with package name
+	Caller *runtime.Frame
+
+	// Message passed to Trace, Debug, Info, Warn, Error, Fatal or Panic
+	Message string
+
+	// When formatter is called in entry.log(), a Buffer may be set to entry
+	Buffer *bytes.Buffer
+
+	// err may contain a field formatting error
+	err string
+}
+
+func NewEntry(logger *Logger) *Entry {
+	return &Entry{
+		Logger: logger,
+		// Default is three fields, plus one optional.  Give a little extra room.
+		Data: make(Fields, 6),
+	}
+}
+
+// Returns the string representation from the reader and ultimately the
+// formatter.
+func (entry *Entry) String() (string, error) {
+	serialized, err := entry.Logger.Formatter.Format(entry)
+	if err != nil {
+		return "", err
+	}
+	str := string(serialized)
+	return str, nil
+}
+
+// Add an error as single field (using the key defined in ErrorKey) to the Entry.
+func (entry *Entry) WithError(err error) *Entry {
+	return entry.WithField(ErrorKey, err)
+}
+
+// Add a single field to the Entry.
+func (entry *Entry) WithField(key string, value interface{}) *Entry {
+	return entry.WithFields(Fields{key: value})
+}
+
+// Add a map of fields to the Entry.
+func (entry *Entry) WithFields(fields Fields) *Entry {
+	data := make(Fields, len(entry.Data)+len(fields))
+	for k, v := range entry.Data {
+		data[k] = v
+	}
+	fieldErr := entry.err
+	for k, v := range fields {
+		isErrField := false
+		if t := reflect.TypeOf(v); t != nil {
+			switch t.Kind() {
+			case reflect.Func:
+				isErrField = true
+			case reflect.Ptr:
+				isErrField = t.Elem().Kind() == reflect.Func
+			}
+		}
+		if isErrField {
+			tmp := fmt.Sprintf("can not add field %q", k)
+			if fieldErr != "" {
+				fieldErr = entry.err + ", " + tmp
+			} else {
+				fieldErr = tmp
+			}
+		} else {
+			data[k] = v
+		}
+	}
+	return &Entry{Logger: entry.Logger, Data: data, Time: entry.Time, err: fieldErr}
+}
+
+// Overrides the time of the Entry.
+func (entry *Entry) WithTime(t time.Time) *Entry {
+	return &Entry{Logger: entry.Logger, Data: entry.Data, Time: t, err: entry.err}
+}
+
+// getPackageName reduces a fully qualified function name to the package name
+// There really ought to be to be a better way...
+func getPackageName(f string) string {
+	for {
+		lastPeriod := strings.LastIndex(f, ".")
+		lastSlash := strings.LastIndex(f, "/")
+		if lastPeriod > lastSlash {
+			f = f[:lastPeriod]
+		} else {
+			break
+		}
+	}
+
+	return f
+}
+
+// getCaller retrieves the name of the first non-logrus calling function
+func getCaller() *runtime.Frame {
+	// Restrict the lookback frames to avoid runaway lookups
+	pcs := make([]uintptr, maximumCallerDepth)
+	depth := runtime.Callers(minimumCallerDepth, pcs)
+	frames := runtime.CallersFrames(pcs[:depth])
+
+	// cache this package's fully-qualified name
+	callerInitOnce.Do(func() {
+		logrusPackage = getPackageName(runtime.FuncForPC(pcs[0]).Name())
+
+		// now that we have the cache, we can skip a minimum count of known-logrus functions
+		// XXX this is dubious, the number of frames may vary store an entry in a logger interface
+		minimumCallerDepth = knownLogrusFrames
+	})
+
+	for f, again := frames.Next(); again; f, again = frames.Next() {
+		pkg := getPackageName(f.Function)
+
+		// If the caller isn't part of this package, we're done
+		if pkg != logrusPackage {
+			return &f
+		}
+	}
+
+	// if we got here, we failed to find the caller's context
+	return nil
+}
+
+func (entry Entry) HasCaller() (has bool) {
+	return entry.Logger != nil &&
+		entry.Logger.ReportCaller &&
+		entry.Caller != nil
+}
+
+// This function is not declared with a pointer value because otherwise
+// race conditions will occur when using multiple goroutines
+func (entry Entry) log(level Level, msg string) {
+	var buffer *bytes.Buffer
+
+	// Default to now, but allow users to override if they want.
+	//
+	// We don't have to worry about polluting future calls to Entry#log()
+	// with this assignment because this function is declared with a
+	// non-pointer receiver.
+	if entry.Time.IsZero() {
+		entry.Time = time.Now()
+	}
+
+	entry.Level = level
+	entry.Message = msg
+	if entry.Logger.ReportCaller {
+		entry.Caller = getCaller()
+	}
+
+	entry.fireHooks()
+
+	buffer = bufferPool.Get().(*bytes.Buffer)
+	buffer.Reset()
+	defer bufferPool.Put(buffer)
+	entry.Buffer = buffer
+
+	entry.write()
+
+	entry.Buffer = nil
+
+	// To avoid Entry#log() returning a value that only would make sense for
+	// panic() to use in Entry#Panic(), we avoid the allocation by checking
+	// directly here.
+	if level <= PanicLevel {
+		panic(&entry)
+	}
+}
+
+func (entry *Entry) fireHooks() {
+	entry.Logger.mu.Lock()
+	defer entry.Logger.mu.Unlock()
+	err := entry.Logger.Hooks.Fire(entry.Level, entry)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to fire hook: %v\n", err)
+	}
+}
+
+func (entry *Entry) write() {
+	entry.Logger.mu.Lock()
+	defer entry.Logger.mu.Unlock()
+	serialized, err := entry.Logger.Formatter.Format(entry)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to obtain reader, %v\n", err)
+	} else {
+		_, err = entry.Logger.Out.Write(serialized)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to write to log, %v\n", err)
+		}
+	}
+}
+
+func (entry *Entry) Log(level Level, args ...interface{}) {
+	if entry.Logger.IsLevelEnabled(level) {
+		entry.log(level, fmt.Sprint(args...))
+	}
+}
+
+func (entry *Entry) Trace(args ...interface{}) {
+	entry.Log(TraceLevel, args...)
+}
+
+func (entry *Entry) Debug(args ...interface{}) {
+	entry.Log(DebugLevel, args...)
+}
+
+func (entry *Entry) Print(args ...interface{}) {
+	entry.Info(args...)
+}
+
+func (entry *Entry) Info(args ...interface{}) {
+	entry.Log(InfoLevel, args...)
+}
+
+func (entry *Entry) Warn(args ...interface{}) {
+	entry.Log(WarnLevel, args...)
+}
+
+func (entry *Entry) Warning(args ...interface{}) {
+	entry.Warn(args...)
+}
+
+func (entry *Entry) Error(args ...interface{}) {
+	entry.Log(ErrorLevel, args...)
+}
+
+func (entry *Entry) Fatal(args ...interface{}) {
+	entry.Log(FatalLevel, args...)
+	entry.Logger.Exit(1)
+}
+
+func (entry *Entry) Panic(args ...interface{}) {
+	entry.Log(PanicLevel, args...)
+	panic(fmt.Sprint(args...))
+}
+
+// Entry Printf family functions
+
+func (entry *Entry) Logf(level Level, format string, args ...interface{}) {
+	entry.Log(level, fmt.Sprintf(format, args...))
+}
+
+func (entry *Entry) Tracef(format string, args ...interface{}) {
+	entry.Logf(TraceLevel, format, args...)
+}
+
+func (entry *Entry) Debugf(format string, args ...interface{}) {
+	entry.Logf(DebugLevel, format, args...)
+}
+
+func (entry *Entry) Infof(format string, args ...interface{}) {
+	entry.Logf(InfoLevel, format, args...)
+}
+
+func (entry *Entry) Printf(format string, args ...interface{}) {
+	entry.Infof(format, args...)
+}
+
+func (entry *Entry) Warnf(format string, args ...interface{}) {
+	entry.Logf(WarnLevel, format, args...)
+}
+
+func (entry *Entry) Warningf(format string, args ...interface{}) {
+	entry.Warnf(format, args...)
+}
+
+func (entry *Entry) Errorf(format string, args ...interface{}) {
+	entry.Logf(ErrorLevel, format, args...)
+}
+
+func (entry *Entry) Fatalf(format string, args ...interface{}) {
+	entry.Logf(FatalLevel, format, args...)
+	entry.Logger.Exit(1)
+}
+
+func (entry *Entry) Panicf(format string, args ...interface{}) {
+	entry.Logf(PanicLevel, format, args...)
+}
+
+// Entry Println family functions
+
+func (entry *Entry) Logln(level Level, args ...interface{}) {
+	if entry.Logger.IsLevelEnabled(level) {
+		entry.Log(level, entry.sprintlnn(args...))
+	}
+}
+
+func (entry *Entry) Traceln(args ...interface{}) {
+	entry.Logln(TraceLevel, args...)
+}
+
+func (entry *Entry) Debugln(args ...interface{}) {
+	entry.Logln(DebugLevel, args...)
+}
+
+func (entry *Entry) Infoln(args ...interface{}) {
+	entry.Logln(InfoLevel, args...)
+}
+
+func (entry *Entry) Println(args ...interface{}) {
+	entry.Infoln(args...)
+}
+
+func (entry *Entry) Warnln(args ...interface{}) {
+	entry.Logln(WarnLevel, args...)
+}
+
+func (entry *Entry) Warningln(args ...interface{}) {
+	entry.Warnln(args...)
+}
+
+func (entry *Entry) Errorln(args ...interface{}) {
+	entry.Logln(ErrorLevel, args...)
+}
+
+func (entry *Entry) Fatalln(args ...interface{}) {
+	entry.Logln(FatalLevel, args...)
+	entry.Logger.Exit(1)
+}
+
+func (entry *Entry) Panicln(args ...interface{}) {
+	entry.Logln(PanicLevel, args...)
+}
+
+// Sprintlnn => Sprint no newline. This is to get the behavior of how
+// fmt.Sprintln where spaces are always added between operands, regardless of
+// their type. Instead of vendoring the Sprintln implementation to spare a
+// string allocation, we do the simplest thing.
+func (entry *Entry) sprintlnn(args ...interface{}) string {
+	msg := fmt.Sprintln(args...)
+	return msg[:len(msg)-1]
+}