cmd, dashboard, log: log collection and exploration (#17097)

* cmd, dashboard, internal, log, node: logging feature

* cmd, dashboard, internal, log: requested changes

* dashboard, vendor: gofmt, govendor, use vendored file watcher

* dashboard, log: gofmt -s -w, goimports

* dashboard, log: gosimple

vendor/github.com/mohae/deepcopy/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Joel
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/mohae/deepcopy/README.md

@@ -0,0 +1,8 @@
+deepCopy
+========
+[![GoDoc](https://godoc.org/github.com/mohae/deepcopy?status.svg)](https://godoc.org/github.com/mohae/deepcopy)[![Build Status](https://travis-ci.org/mohae/deepcopy.png)](https://travis-ci.org/mohae/deepcopy)
+
+DeepCopy makes deep copies of things: unexported field values are not copied.
+
+## Usage
+    cpy := deepcopy.Copy(orig)

vendor/github.com/mohae/deepcopy/deepcopy.go

@@ -0,0 +1,125 @@
+// deepcopy makes deep copies of things. A standard copy will copy the
+// pointers: deep copy copies the values pointed to.  Unexported field
+// values are not copied.
+//
+// Copyright (c)2014-2016, Joel Scoble (github.com/mohae), all rights reserved.
+// License: MIT, for more details check the included LICENSE file.
+package deepcopy
+
+import (
+	"reflect"
+	"time"
+)
+
+// Interface for delegating copy process to type
+type Interface interface {
+	DeepCopy() interface{}
+}
+
+// Iface is an alias to Copy; this exists for backwards compatibility reasons.
+func Iface(iface interface{}) interface{} {
+	return Copy(iface)
+}
+
+// Copy creates a deep copy of whatever is passed to it and returns the copy
+// in an interface{}.  The returned value will need to be asserted to the
+// correct type.
+func Copy(src interface{}) interface{} {
+	if src == nil {
+		return nil
+	}
+
+	// Make the interface a reflect.Value
+	original := reflect.ValueOf(src)
+
+	// Make a copy of the same type as the original.
+	cpy := reflect.New(original.Type()).Elem()
+
+	// Recursively copy the original.
+	copyRecursive(original, cpy)
+
+	// Return the copy as an interface.
+	return cpy.Interface()
+}
+
+// copyRecursive does the actual copying of the interface. It currently has
+// limited support for what it can handle. Add as needed.
+func copyRecursive(original, cpy reflect.Value) {
+	// check for implement deepcopy.Interface
+	if original.CanInterface() {
+		if copier, ok := original.Interface().(Interface); ok {
+			cpy.Set(reflect.ValueOf(copier.DeepCopy()))
+			return
+		}
+	}
+
+	// handle according to original's Kind
+	switch original.Kind() {
+	case reflect.Ptr:
+		// Get the actual value being pointed to.
+		originalValue := original.Elem()
+
+		// if  it isn't valid, return.
+		if !originalValue.IsValid() {
+			return
+		}
+		cpy.Set(reflect.New(originalValue.Type()))
+		copyRecursive(originalValue, cpy.Elem())
+
+	case reflect.Interface:
+		// If this is a nil, don't do anything
+		if original.IsNil() {
+			return
+		}
+		// Get the value for the interface, not the pointer.
+		originalValue := original.Elem()
+
+		// Get the value by calling Elem().
+		copyValue := reflect.New(originalValue.Type()).Elem()
+		copyRecursive(originalValue, copyValue)
+		cpy.Set(copyValue)
+
+	case reflect.Struct:
+		t, ok := original.Interface().(time.Time)
+		if ok {
+			cpy.Set(reflect.ValueOf(t))
+			return
+		}
+		// Go through each field of the struct and copy it.
+		for i := 0; i < original.NumField(); i++ {
+			// The Type's StructField for a given field is checked to see if StructField.PkgPath
+			// is set to determine if the field is exported or not because CanSet() returns false
+			// for settable fields.  I'm not sure why.  -mohae
+			if original.Type().Field(i).PkgPath != "" {
+				continue
+			}
+			copyRecursive(original.Field(i), cpy.Field(i))
+		}
+
+	case reflect.Slice:
+		if original.IsNil() {
+			return
+		}
+		// Make a new slice and copy each element.
+		cpy.Set(reflect.MakeSlice(original.Type(), original.Len(), original.Cap()))
+		for i := 0; i < original.Len(); i++ {
+			copyRecursive(original.Index(i), cpy.Index(i))
+		}
+
+	case reflect.Map:
+		if original.IsNil() {
+			return
+		}
+		cpy.Set(reflect.MakeMap(original.Type()))
+		for _, key := range original.MapKeys() {
+			originalValue := original.MapIndex(key)
+			copyValue := reflect.New(originalValue.Type()).Elem()
+			copyRecursive(originalValue, copyValue)
+			copyKey := Copy(key.Interface())
+			cpy.SetMapIndex(reflect.ValueOf(copyKey), copyValue)
+		}
+
+	default:
+		cpy.Set(original)
+	}
+}