Update fluent-logger-golang to v1.2.0.

Fix race condition issue to solve an issue about "panic: runtime error: invalid memory address or nil pointer dereference".
This fix stabilize Docker daemon under the situation of communication problem with Fluentd processes.

Signed-off-by: Satoshi Tagomori <tagomoris@gmail.com>
(cherry picked from commit 87124b9d62bc71f7632126cf7f8d5eb805c4a7f1)
Signed-off-by: Victor Vieux <vieux@docker.com>

hack/vendor.sh

@@ -114,7 +114,7 @@ clone git github.com/golang/protobuf 3c84672111d91bb5ac31719e112f9f7126a0e26e
 # gelf logging driver deps
 clone git github.com/Graylog2/go-gelf aab2f594e4585d43468ac57287b0dece9d806883
 
-clone git github.com/fluent/fluent-logger-golang v1.1.0
+clone git github.com/fluent/fluent-logger-golang v1.2.0
 # fluent-logger-golang deps
 clone git github.com/philhofer/fwd 899e4efba8eaa1fea74175308f3fae18ff3319fa
 clone git github.com/tinylib/msgp 75ee40d2601edf122ef667e2a07d600d4c44490c

vendor/src/github.com/fluent/fluent-logger-golang/LICENSE

@@ -1,13 +1,202 @@
-Copyright (c) 2013 Tatsuo Kaniwa
 
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
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vendor/src/github.com/fluent/fluent-logger-golang/fluent/fluent.go

@@ -1,6 +1,7 @@
 package fluent
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -25,24 +26,28 @@ const (
 )
 
 type Config struct {
-	FluentPort       int
-	FluentHost       string
-	FluentNetwork    string
-	FluentSocketPath string
-	Timeout          time.Duration
-	BufferLimit      int
-	RetryWait        int
-	MaxRetry         int
-	TagPrefix        string
-	AsyncConnect     bool
+	FluentPort       int           `json:"fluent_port"`
+	FluentHost       string        `json:"fluent_host"`
+	FluentNetwork    string        `json:"fluent_network"`
+	FluentSocketPath string        `json:"fluent_socket_path"`
+	Timeout          time.Duration `json:"timeout"`
+	BufferLimit      int           `json:"buffer_limit"`
+	RetryWait        int           `json:"retry_wait"`
+	MaxRetry         int           `json:"max_retry"`
+	TagPrefix        string        `json:"tag_prefix"`
+	AsyncConnect     bool          `json:"async_connect"`
+	MarshalAsJSON    bool          `json:"marshal_as_json"`
 }
 
 type Fluent struct {
 	Config
+
+	mubuff  sync.Mutex
+	pending []byte
+
+	muconn       sync.Mutex
 	conn         io.WriteCloser
-	pending      []byte
 	reconnecting bool
-	mu           sync.Mutex
 }
 
 // New creates a new Logger.
@@ -140,9 +145,9 @@ func (f *Fluent) PostWithTime(tag string, tm time.Time, message interface{}) err
 	}
 
 	if msgtype.Kind() != reflect.Map {
-		return errors.New("messge must be a map")
+		return errors.New("fluent#PostWithTime: message must be a map")
 	} else if msgtype.Key().Kind() != reflect.String {
-		return errors.New("map keys must be strings")
+		return errors.New("fluent#PostWithTime: map keys must be strings")
 	}
 
 	kv := make(map[string]interface{})
@@ -154,33 +159,54 @@ func (f *Fluent) PostWithTime(tag string, tm time.Time, message interface{}) err
 }
 
 func (f *Fluent) EncodeAndPostData(tag string, tm time.Time, message interface{}) error {
-	if data, dumperr := f.EncodeData(tag, tm, message); dumperr != nil {
-		return fmt.Errorf("fluent#EncodeAndPostData: can't convert '%s' to msgpack:%s", message, dumperr)
-		// fmt.Println("fluent#Post: can't convert to msgpack:", message, dumperr)
-	} else {
-		f.PostRawData(data)
-		return nil
+	var data []byte
+	var err error
+	if data, err = f.EncodeData(tag, tm, message); err != nil {
+		return fmt.Errorf("fluent#EncodeAndPostData: can't convert '%#v' to msgpack:%v", message, err)
 	}
+	return f.postRawData(data)
 }
 
+// Deprecated: Use EncodeAndPostData instead
 func (f *Fluent) PostRawData(data []byte) {
-	f.mu.Lock()
-	f.pending = append(f.pending, data...)
-	f.mu.Unlock()
+	f.postRawData(data)
+}
+
+func (f *Fluent) postRawData(data []byte) error {
+	if err := f.appendBuffer(data); err != nil {
+		return err
+	}
 	if err := f.send(); err != nil {
 		f.close()
-		if len(f.pending) > f.Config.BufferLimit {
-			f.flushBuffer()
-		}
-	} else {
-		f.flushBuffer()
+		return err
 	}
+	return nil
+}
+
+// For sending forward protocol adopted JSON
+type MessageChunk struct {
+	message Message
+}
+
+// Golang default marshaler does not support
+// ["value", "value2", {"key":"value"}] style marshaling.
+// So, it should write JSON marshaler by hand.
+func (chunk *MessageChunk) MarshalJSON() ([]byte, error) {
+	data, err := json.Marshal(chunk.message.Record)
+	return []byte(fmt.Sprintf("[\"%s\",%d,%s,null]", chunk.message.Tag,
+		chunk.message.Time, data)), err
 }
 
 func (f *Fluent) EncodeData(tag string, tm time.Time, message interface{}) (data []byte, err error) {
 	timeUnix := tm.Unix()
-	msg := &Message{Tag: tag, Time: timeUnix, Record: message}
-	data, err = msg.MarshalMsg(nil)
+	if f.Config.MarshalAsJSON {
+		msg := Message{Tag: tag, Time: timeUnix, Record: message}
+		chunk := &MessageChunk{message: msg}
+		data, err = json.Marshal(chunk)
+	} else {
+		msg := &Message{Tag: tag, Time: timeUnix, Record: message}
+		data, err = msg.MarshalMsg(nil)
+	}
 	return
 }
 
@@ -193,23 +219,32 @@ func (f *Fluent) Close() (err error) {
 	return
 }
 
-// close closes the connection.
-func (f *Fluent) close() (err error) {
-	if f.conn != nil {
-		f.mu.Lock()
-		defer f.mu.Unlock()
-	} else {
-		return
+// appendBuffer appends data to buffer with lock.
+func (f *Fluent) appendBuffer(data []byte) error {
+	f.mubuff.Lock()
+	defer f.mubuff.Unlock()
+	if len(f.pending)+len(data) > f.Config.BufferLimit {
+		return errors.New(fmt.Sprintf("fluent#appendBuffer: Buffer full, limit %v", f.Config.BufferLimit))
 	}
+	f.pending = append(f.pending, data...)
+	return nil
+}
+
+// close closes the connection.
+func (f *Fluent) close() {
+	f.muconn.Lock()
 	if f.conn != nil {
 		f.conn.Close()
 		f.conn = nil
 	}
-	return
+	f.muconn.Unlock()
 }
 
 // connect establishes a new connection using the specified transport.
 func (f *Fluent) connect() (err error) {
+	f.muconn.Lock()
+	defer f.muconn.Unlock()
+
 	switch f.Config.FluentNetwork {
 	case "tcp":
 		f.conn, err = net.DialTimeout(f.Config.FluentNetwork, f.Config.FluentHost+":"+strconv.Itoa(f.Config.FluentPort), f.Config.Timeout)
@@ -218,6 +253,10 @@ func (f *Fluent) connect() (err error) {
 	default:
 		err = net.UnknownNetworkError(f.Config.FluentNetwork)
 	}
+
+	if err != nil {
+		f.reconnecting = false
+	}
 	return
 }
 
@@ -226,44 +265,45 @@ func e(x, y float64) int {
 }
 
 func (f *Fluent) reconnect() {
-	go func() {
-		for i := 0; ; i++ {
-			err := f.connect()
-			if err == nil {
-				f.mu.Lock()
-				f.reconnecting = false
-				f.mu.Unlock()
-				break
-			} else {
-				if i == f.Config.MaxRetry {
-					panic("fluent#reconnect: failed to reconnect!")
-				}
-				waitTime := f.Config.RetryWait * e(defaultReconnectWaitIncreRate, float64(i-1))
-				time.Sleep(time.Duration(waitTime) * time.Millisecond)
-			}
+	for i := 0; ; i++ {
+		err := f.connect()
+		if err == nil {
+			f.send()
+			return
+		}
+		if i == f.Config.MaxRetry {
+			// TODO: What we can do when connection failed MaxRetry times?
+			panic("fluent#reconnect: failed to reconnect!")
 		}
-	}()
+		waitTime := f.Config.RetryWait * e(defaultReconnectWaitIncreRate, float64(i-1))
+		time.Sleep(time.Duration(waitTime) * time.Millisecond)
+	}
 }
 
-func (f *Fluent) flushBuffer() {
-	f.mu.Lock()
-	defer f.mu.Unlock()
-	f.pending = f.pending[0:0]
-}
+func (f *Fluent) send() error {
+	f.muconn.Lock()
+	defer f.muconn.Unlock()
 
-func (f *Fluent) send() (err error) {
 	if f.conn == nil {
 		if f.reconnecting == false {
-			f.mu.Lock()
 			f.reconnecting = true
-			f.mu.Unlock()
-			f.reconnect()
+			go f.reconnect()
 		}
-		err = errors.New("fluent#send: can't send logs, client is reconnecting")
-	} else {
-		f.mu.Lock()
+		return errors.New("fluent#send: can't send logs, client is reconnecting")
+	}
+
+	f.mubuff.Lock()
+	defer f.mubuff.Unlock()
+
+	var err error
+	if len(f.pending) > 0 {
 		_, err = f.conn.Write(f.pending)
-		f.mu.Unlock()
+		if err != nil {
+			f.conn.Close()
+			f.conn = nil
+		} else {
+			f.pending = f.pending[:0]
+		}
 	}
-	return
+	return err
 }