Merge pull request #42979 from akerouanton/bump-fluent-logger

vendor: github.com/fluent/fluent-logger-golang v1.8.0

daemon/logger/fluentd/fluentd.go

@@ -242,6 +242,7 @@ func parseConfig(cfg map[string]string) (fluent.Config, error) {
 		AsyncConnect:       asyncConnect,
 		SubSecondPrecision: subSecondPrecision,
 		RequestAck:         requestAck,
+		ForceStopAsyncSend: async || asyncConnect,
 	}
 
 	return config, nil

vendor.conf

@@ -103,7 +103,7 @@ github.com/godbus/dbus/v5                           c88335c0b1d28a30e7fc76d526a0
 github.com/Graylog2/go-gelf                         1550ee647df0510058c9d67a45c56f18911d80b8 # v2 branch
 
 # fluent-logger-golang deps
-github.com/fluent/fluent-logger-golang              b9b7fb02ccfee8ba4e69aa87386820c2bf24fd11 # v1.6.1
+github.com/fluent/fluent-logger-golang              0b652e850a9140d0b1db6390d8925d0601e952db # v1.8.0
 github.com/philhofer/fwd                            bb6d471dc95d4fe11e432687f8b70ff496cf3136 # v1.0.0
 github.com/tinylib/msgp                             af6442a0fcf6e2a1b824f70dd0c734f01e817751 # v1.1.0
 

vendor/github.com/fluent/fluent-logger-golang/README.md

@@ -1,7 +1,7 @@
 fluent-logger-golang
 ====
 
-[![Build Status](https://travis-ci.org/fluent/fluent-logger-golang.png?branch=master)](https://travis-ci.org/fluent/fluent-logger-golang)
+[![Build Status](https://github.com/fluent/fluent-logger-golang/actions/workflows/ci.yaml/badge.svg?branch=master)](https://github.com/fluent/fluent-logger-golang/actions)
 [![GoDoc](https://godoc.org/github.com/fluent/fluent-logger-golang/fluent?status.svg)](https://godoc.org/github.com/fluent/fluent-logger-golang/fluent)
 
 ## A structured event logger for Fluentd (Golang)
@@ -60,7 +60,12 @@ f := fluent.New(fluent.Config{FluentPort: 80, FluentHost: "example.com"})
 
 ### FluentNetwork
 
-Specify the network protocol, as "tcp" (use `FluentHost` and `FluentPort`) or "unix" (use `FluentSocketPath`).
+Specify the network protocol. The supported values are:
+
+ * "tcp" (use `FluentHost` and `FluentPort`)
+ * "tls" (use`FluentHost` and `FluentPort`)
+ * "unix" (use `FluentSocketPath`)
+
 The default is "tcp".
 
 ### FluentHost
@@ -121,6 +126,12 @@ The default is false.
 When Async is enabled, immediately discard the event queue on close() and return (instead of trying MaxRetry times for each event in the queue before returning)
 The default is false.
 
+### AsyncResultCallback
+
+When Async is enabled, if this is callback is provided, it will be called on every write to Fluentd. The callback function
+takes two arguments - a `[]byte` of the message that was to be sent and an `error`. If the `error` is not nil this means the 
+delivery of the message was unsuccessful.
+
 ### SubSecondPrecision
 
 Enable time encoding as EventTime, which contains sub-second precision values. The messages encoded with this option can be received only by Fluentd v0.14 or later.
@@ -136,6 +147,10 @@ The default is false.
 Sets whether to request acknowledgment from Fluentd to increase the reliability
 of the connection. The default is false.
 
+### TlsInsecureSkipVerify
+
+Skip verifying the server certificate. Useful for development and testing. The default is false.
+
 ## FAQ
 
 ### Does this logger support the features of Fluentd Forward Protocol v1?
@@ -144,7 +159,24 @@ of the connection. The default is false.
 
 This logger doesn't support those features. Patches are welcome!
 
+### Is it allowed to call `Fluent.Post()` after connection close?
+
+Before v1.8.0, the Fluent logger silently reopened connections whenever
+`Fluent.Post()` was called.
+
+```go
+logger, _ := fluent.New(fluent.Config{})
+logger.Post(tag, data)
+logger.Close()
+logger.Post(tag, data)  /* reopen connection */
+```
+
+However, this behavior was confusing, in particular when multiple goroutines
+were involved. Starting v1.8.0, the logger no longer accepts `Fluent.Post()`
+after `Fluent.Close()`, and instead returns a "Logger already closed" error.
+
 ## Tests
 ```
+
 go test
 ```

vendor/github.com/fluent/fluent-logger-golang/fluent/fluent.go

@@ -1,10 +1,13 @@
 package fluent
 
 import (
+	"context"
+	"crypto/tls"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"math"
+	"math/rand"
 	"net"
 	"os"
 	"reflect"
@@ -15,7 +18,6 @@ import (
 	"bytes"
 	"encoding/base64"
 	"encoding/binary"
-	"math/rand"
 
 	"github.com/tinylib/msgp/msgp"
 )
@@ -35,22 +37,30 @@ const (
 	// Default sub-second precision value to false since it is only compatible
 	// with fluentd versions v0.14 and above.
 	defaultSubSecondPrecision = false
+
+	// Default value whether to skip checking insecure certs on TLS connections.
+	defaultTlsInsecureSkipVerify = false
 )
 
+// randomGenerator is used by getUniqueId to generate ack hashes. Its value is replaced
+// during tests with a deterministic function.
+var randomGenerator = rand.Uint64
+
 type Config struct {
-	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"`
-	WriteTimeout       time.Duration `json:"write_timeout"`
-	BufferLimit        int           `json:"buffer_limit"`
-	RetryWait          int           `json:"retry_wait"`
-	MaxRetry           int           `json:"max_retry"`
-	MaxRetryWait       int           `json:"max_retry_wait"`
-	TagPrefix          string        `json:"tag_prefix"`
-	Async              bool          `json:"async"`
-	ForceStopAsyncSend bool          `json:"force_stop_async_send"`
+	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"`
+	WriteTimeout        time.Duration `json:"write_timeout"`
+	BufferLimit         int           `json:"buffer_limit"`
+	RetryWait           int           `json:"retry_wait"`
+	MaxRetry            int           `json:"max_retry"`
+	MaxRetryWait        int           `json:"max_retry_wait"`
+	TagPrefix           string        `json:"tag_prefix"`
+	Async               bool          `json:"async"`
+	ForceStopAsyncSend  bool          `json:"force_stop_async_send"`
+	AsyncResultCallback func(data []byte, err error)
 	// Deprecated: Use Async instead
 	AsyncConnect  bool `json:"async_connect"`
 	MarshalAsJSON bool `json:"marshal_as_json"`
@@ -63,6 +73,9 @@ type Config struct {
 	// respond with an acknowledgement. This option improves the reliability
 	// of the message transmission.
 	RequestAck bool `json:"request_ack"`
+
+	// Flag to skip verifying insecure certs on TLS connections
+	TlsInsecureSkipVerify bool `json: "tls_insecure_skip_verify"`
 }
 
 type ErrUnknownNetwork struct {
@@ -85,17 +98,24 @@ type msgToSend struct {
 type Fluent struct {
 	Config
 
-	dialer       dialer
-	stopRunning  chan bool
-	pending      chan *msgToSend
-	pendingMutex sync.RWMutex
-	chanClosed   bool
-	wg           sync.WaitGroup
-
-	muconn sync.Mutex
+	dialer dialer
+	// stopRunning is used in async mode to signal to run() it should abort.
+	stopRunning chan struct{}
+	// cancelDialings is used by Close() to stop any in-progress dialing.
+	cancelDialings context.CancelFunc
+	pending        chan *msgToSend
+	pendingMutex   sync.RWMutex
+	closed         bool
+	wg             sync.WaitGroup
+
+	muconn sync.RWMutex
 	conn   net.Conn
 }
 
+type dialer interface {
+	DialContext(ctx context.Context, network, address string) (net.Conn, error)
+}
+
 // New creates a new Logger.
 func New(config Config) (*Fluent, error) {
 	if config.Timeout == 0 {
@@ -106,10 +126,6 @@ func New(config Config) (*Fluent, error) {
 	})
 }
 
-type dialer interface {
-	Dial(string, string) (net.Conn, error)
-}
-
 func newWithDialer(config Config, d dialer) (f *Fluent, err error) {
 	if config.FluentNetwork == "" {
 		config.FluentNetwork = defaultNetwork
@@ -138,27 +154,36 @@ func newWithDialer(config Config, d dialer) (f *Fluent, err error) {
 	if config.MaxRetryWait == 0 {
 		config.MaxRetryWait = defaultMaxRetryWait
 	}
+	if !config.TlsInsecureSkipVerify {
+		config.TlsInsecureSkipVerify = defaultTlsInsecureSkipVerify
+	}
 	if config.AsyncConnect {
 		fmt.Fprintf(os.Stderr, "fluent#New: AsyncConnect is now deprecated, please use Async instead")
 		config.Async = config.Async || config.AsyncConnect
 	}
 
 	if config.Async {
+		ctx, cancel := context.WithCancel(context.Background())
+
 		f = &Fluent{
-			Config:       config,
-			dialer:       d,
-			pending:      make(chan *msgToSend, config.BufferLimit),
-			pendingMutex: sync.RWMutex{},
-			stopRunning:  make(chan bool, 1),
+			Config:         config,
+			dialer:         d,
+			stopRunning:    make(chan struct{}),
+			cancelDialings: cancel,
+			pending:        make(chan *msgToSend, config.BufferLimit),
+			pendingMutex:   sync.RWMutex{},
+			muconn:         sync.RWMutex{},
 		}
+
 		f.wg.Add(1)
-		go f.run()
+		go f.run(ctx)
 	} else {
 		f = &Fluent{
 			Config: config,
 			dialer: d,
+			muconn: sync.RWMutex{},
 		}
-		err = f.connect()
+		err = f.connect(context.Background())
 	}
 	return
 }
@@ -211,13 +236,18 @@ func (f *Fluent) PostWithTime(tag string, tm time.Time, message interface{}) err
 		fields := msgtype.NumField()
 		for i := 0; i < fields; i++ {
 			field := msgtype.Field(i)
+			value := msg.FieldByIndex(field.Index)
+			// ignore unexported fields
+			if !value.CanInterface() {
+				continue
+			}
 			name := field.Name
 			if n1 := field.Tag.Get("msg"); n1 != "" {
 				name = n1
 			} else if n2 := field.Tag.Get("codec"); n2 != "" {
 				name = n2
 			}
-			kv[name] = msg.FieldByIndex(field.Index).Interface()
+			kv[name] = value.Interface()
 		}
 		return f.EncodeAndPostData(tag, tm, kv)
 	}
@@ -254,8 +284,12 @@ func (f *Fluent) postRawData(msg *msgToSend) error {
 	if f.Config.Async {
 		return f.appendBuffer(msg)
 	}
+
 	// Synchronous write
-	return f.write(msg)
+	if f.closed {
+		return fmt.Errorf("fluent#postRawData: Logger already closed")
+	}
+	return f.writeWithRetry(context.Background(), msg)
 }
 
 // For sending forward protocol adopted JSON
@@ -289,7 +323,7 @@ func getUniqueID(timeUnix int64) (string, error) {
 		enc.Close()
 		return "", err
 	}
-	if err := binary.Write(enc, binary.LittleEndian, rand.Uint64()); err != nil {
+	if err := binary.Write(enc, binary.LittleEndian, randomGenerator()); err != nil {
 		enc.Close()
 		return "", err
 	}
@@ -325,32 +359,53 @@ func (f *Fluent) EncodeData(tag string, tm time.Time, message interface{}) (msg
 	return
 }
 
-// Close closes the connection, waiting for pending logs to be sent
+// Close closes the connection, waiting for pending logs to be sent. If the client is
+// running in async mode, the run() goroutine exits before Close() returns.
 func (f *Fluent) Close() (err error) {
-	defer f.close(f.conn)
 	if f.Config.Async {
 		f.pendingMutex.Lock()
-		if f.chanClosed {
+		if f.closed {
 			f.pendingMutex.Unlock()
 			return nil
 		}
-		f.chanClosed = true
+		f.closed = true
 		f.pendingMutex.Unlock()
+
 		if f.Config.ForceStopAsyncSend {
-			f.stopRunning <- true
 			close(f.stopRunning)
+			f.cancelDialings()
 		}
+
 		close(f.pending)
+		// If ForceStopAsyncSend is false, all logs in the channel have to be sent
+		// before closing the connection. At this point closed is true so no more
+		// logs are written to the channel and f.pending has been closed, so run()
+		// goroutine will exit as soon as all logs in the channel are sent.
+		if !f.Config.ForceStopAsyncSend {
+			f.wg.Wait()
+		}
+	}
+
+	f.muconn.Lock()
+	f.close()
+	f.closed = true
+	f.muconn.Unlock()
+
+	// If ForceStopAsyncSend is true, we shall close the connection before waiting for
+	// run() goroutine to exit to be sure we aren't waiting on ack message that might
+	// never come (eg. because fluentd server is down). However we want to be sure the
+	// run() goroutine stops before returning from Close().
+	if f.Config.ForceStopAsyncSend {
 		f.wg.Wait()
 	}
-	return nil
+	return
 }
 
 // appendBuffer appends data to buffer with lock.
 func (f *Fluent) appendBuffer(msg *msgToSend) error {
 	f.pendingMutex.RLock()
 	defer f.pendingMutex.RUnlock()
-	if f.chanClosed {
+	if f.closed {
 		return fmt.Errorf("fluent#appendBuffer: Logger already closed")
 	}
 	select {
@@ -361,58 +416,114 @@ func (f *Fluent) appendBuffer(msg *msgToSend) error {
 	return nil
 }
 
-// close closes the connection.
-func (f *Fluent) close(c net.Conn) {
-	f.muconn.Lock()
-	if f.conn != nil && f.conn == c {
+// close closes the connection. Callers should take care of locking muconn first.
+func (f *Fluent) close() {
+	if f.conn != nil {
 		f.conn.Close()
 		f.conn = nil
 	}
-	f.muconn.Unlock()
 }
 
-// connect establishes a new connection using the specified transport.
-func (f *Fluent) connect() (err error) {
+// connect establishes a new connection using the specified transport. Caller should
+// take care of locking muconn first.
+func (f *Fluent) connect(ctx context.Context) (err error) {
 	switch f.Config.FluentNetwork {
 	case "tcp":
-		f.conn, err = f.dialer.Dial(
+		f.conn, err = f.dialer.DialContext(ctx,
 			f.Config.FluentNetwork,
 			f.Config.FluentHost+":"+strconv.Itoa(f.Config.FluentPort))
+	case "tls":
+		tlsConfig := &tls.Config{InsecureSkipVerify: f.Config.TlsInsecureSkipVerify}
+		f.conn, err = tls.DialWithDialer(
+			&net.Dialer{Timeout: f.Config.Timeout},
+			"tcp",
+			f.Config.FluentHost+":"+strconv.Itoa(f.Config.FluentPort), tlsConfig,
+		)
 	case "unix":
-		f.conn, err = f.dialer.Dial(
+		f.conn, err = f.dialer.DialContext(ctx,
 			f.Config.FluentNetwork,
 			f.Config.FluentSocketPath)
 	default:
 		err = NewErrUnknownNetwork(f.Config.FluentNetwork)
 	}
+
 	return err
 }
 
-func (f *Fluent) run() {
-	drainEvents := false
-	var emitEventDrainMsg sync.Once
+var errIsClosing = errors.New("fluent logger is closing")
+
+// Caller should take care of locking muconn first.
+func (f *Fluent) connectWithRetry(ctx context.Context) error {
+	// A Time channel is used instead of time.Sleep() to avoid blocking this
+	// goroutine during way too much time (because of the exponential back-off
+	// retry).
+	// time.NewTimer() is used instead of time.After() to avoid leaking the
+	// timer channel (cf. https://pkg.go.dev/time#After).
+	timeout := time.NewTimer(time.Duration(0))
+	defer func() {
+		// timeout.Stop() is called in a function literal instead of being
+		// defered directly as it's re-assigned below when the retry loop spins.
+		timeout.Stop()
+	}()
+
+	for i := 0; i < f.Config.MaxRetry; i++ {
+		select {
+		case <-timeout.C:
+			err := f.connect(ctx)
+			if err == nil {
+				return nil
+			}
+
+			if _, ok := err.(*ErrUnknownNetwork); ok {
+				return err
+			}
+			if err == context.Canceled {
+				return errIsClosing
+			}
+
+			waitTime := f.Config.RetryWait * e(defaultReconnectWaitIncreRate, float64(i-1))
+			if waitTime > f.Config.MaxRetryWait {
+				waitTime = f.Config.MaxRetryWait
+			}
+
+			timeout = time.NewTimer(time.Duration(waitTime) * time.Millisecond)
+		case <-ctx.Done():
+			return errIsClosing
+		}
+	}
+
+	return fmt.Errorf("could not connect to fluentd after %d retries", f.Config.MaxRetry)
+}
+
+// run is the goroutine used to unqueue and write logs in async mode. That
+// goroutine is meant to run during the whole life of the Fluent logger.
+func (f *Fluent) run(ctx context.Context) {
 	for {
 		select {
 		case entry, ok := <-f.pending:
+			// f.stopRunning is closed before f.pending only when ForceStopAsyncSend
+			// is enabled. Otherwise, f.pending is closed when Close() is called.
 			if !ok {
 				f.wg.Done()
 				return
 			}
-			if drainEvents {
-				emitEventDrainMsg.Do(func() { fmt.Fprintf(os.Stderr, "[%s] Discarding queued events...\n", time.Now().Format(time.RFC3339)) })
-				continue
-			}
-			err := f.write(entry)
-			if err != nil {
+
+			err := f.writeWithRetry(ctx, entry)
+			if err != nil && err != errIsClosing {
 				fmt.Fprintf(os.Stderr, "[%s] Unable to send logs to fluentd, reconnecting...\n", time.Now().Format(time.RFC3339))
 			}
-		}
-		select {
-		case stopRunning, ok := <-f.stopRunning:
-			if stopRunning || !ok {
-				drainEvents = true
+			if f.AsyncResultCallback != nil {
+				var data []byte
+				if entry != nil {
+					data = entry.data
+				}
+				f.AsyncResultCallback(data, err)
 			}
-		default:
+		case <-f.stopRunning:
+			fmt.Fprintf(os.Stderr, "[%s] Discarding queued events...\n", time.Now().Format(time.RFC3339))
+
+			f.wg.Done()
+			return
 		}
 	}
 }
@@ -421,63 +532,85 @@ func e(x, y float64) int {
 	return int(math.Pow(x, y))
 }
 
-func (f *Fluent) write(msg *msgToSend) error {
-	var c net.Conn
+func (f *Fluent) writeWithRetry(ctx context.Context, msg *msgToSend) error {
 	for i := 0; i < f.Config.MaxRetry; i++ {
-		c = f.conn
-		// Connect if needed
-		if c == nil {
-			f.muconn.Lock()
-			if f.conn == nil {
-				err := f.connect()
-				if err != nil {
-					f.muconn.Unlock()
-
-					if _, ok := err.(*ErrUnknownNetwork); ok {
-						// do not retry on unknown network error
-						break
-					}
-					waitTime := f.Config.RetryWait * e(defaultReconnectWaitIncreRate, float64(i-1))
-					if waitTime > f.Config.MaxRetryWait {
-						waitTime = f.Config.MaxRetryWait
-					}
-					time.Sleep(time.Duration(waitTime) * time.Millisecond)
-					continue
-				}
-			}
-			c = f.conn
-			f.muconn.Unlock()
+		if retry, err := f.write(ctx, msg); !retry {
+			return err
+		}
+	}
+
+	return fmt.Errorf("fluent#write: failed to write after %d attempts", f.Config.MaxRetry)
+}
+
+// write writes the provided msg to fluentd server. Its first return values is
+// a bool indicating whether the write should be retried.
+// This method relies on function literals to execute muconn.Unlock or
+// muconn.RUnlock in deferred calls to ensure the mutex is unlocked even in
+// the case of panic recovering.
+func (f *Fluent) write(ctx context.Context, msg *msgToSend) (bool, error) {
+	closer := func() {
+		f.muconn.Lock()
+		defer f.muconn.Unlock()
+
+		f.close()
+	}
+
+	if err := func() (err error) {
+		f.muconn.Lock()
+		defer f.muconn.Unlock()
+
+		if f.conn == nil {
+			err = f.connectWithRetry(ctx)
+		}
+
+		return err
+	}(); err != nil {
+		// Here, we don't want to retry the write since connectWithRetry already
+		// retries Config.MaxRetry times to connect.
+		return false, fmt.Errorf("fluent#write: %v", err)
+	}
+
+	if err := func() (err error) {
+		f.muconn.RLock()
+		defer f.muconn.RUnlock()
+
+		if f.conn == nil {
+			return fmt.Errorf("connection has been closed before writing to it")
 		}
 
-		// We're connected, write msg
 		t := f.Config.WriteTimeout
 		if time.Duration(0) < t {
-			c.SetWriteDeadline(time.Now().Add(t))
+			f.conn.SetWriteDeadline(time.Now().Add(t))
 		} else {
-			c.SetWriteDeadline(time.Time{})
+			f.conn.SetWriteDeadline(time.Time{})
 		}
-		_, err := c.Write(msg.data)
-		if err != nil {
-			f.close(c)
+
+		_, err = f.conn.Write(msg.data)
+		return err
+	}(); err != nil {
+		closer()
+		return true, fmt.Errorf("fluent#write: %v", err)
+	}
+
+	// Acknowledgment check
+	if msg.ack != "" {
+		resp := &AckResp{}
+		var err error
+		if f.Config.MarshalAsJSON {
+			dec := json.NewDecoder(f.conn)
+			err = dec.Decode(resp)
 		} else {
-			// Acknowledgment check
-			if msg.ack != "" {
-				resp := &AckResp{}
-				if f.Config.MarshalAsJSON {
-					dec := json.NewDecoder(c)
-					err = dec.Decode(resp)
-				} else {
-					r := msgp.NewReader(c)
-					err = resp.DecodeMsg(r)
-				}
-				if err != nil || resp.Ack != msg.ack {
-					f.close(c)
-					continue
-				}
-			}
-			return err
+			r := msgp.NewReader(f.conn)
+			err = resp.DecodeMsg(r)
+		}
+
+		if err != nil || resp.Ack != msg.ack {
+			fmt.Fprintf(os.Stderr, "fluent#write: message ack (%s) doesn't match expected one (%s). Closing connection...", resp.Ack, msg.ack)
+
+			closer()
+			return true, err
 		}
 	}
 
-	return fmt.Errorf("fluent#write: failed to reconnect, max retry: %v", f.Config.MaxRetry)
+	return false, nil
 }