1 files changed, 251 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/logr/v2/targets/tcp.go b/vendor/github.com/mattermost/logr/v2/targets/tcp.go
new file mode 100644
index 00000000..ce73e034
--- /dev/null
+++ b/vendor/github.com/mattermost/logr/v2/targets/tcp.go
@@ -0,0 +1,251 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package targets
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/mattermost/logr/v2"
+)
+
+const (
+	DialTimeoutSecs             = 30
+	WriteTimeoutSecs            = 30
+	RetryBackoffMillis    int64 = 100
+	MaxRetryBackoffMillis int64 = 30 * 1000 // 30 seconds
+)
+
+// Tcp outputs log records to raw socket server.
+type Tcp struct {
+	options *TcpOptions
+	addy    string
+
+	mutex    sync.Mutex
+	conn     net.Conn
+	monitor  chan struct{}
+	shutdown chan struct{}
+}
+
+// TcpOptions provides parameters for dialing a socket server.
+type TcpOptions struct {
+	IP       string `json:"ip,omitempty"` // deprecated
+	Host     string `json:"host"`
+	Port     int    `json:"port"`
+	TLS      bool   `json:"tls"`
+	Cert     string `json:"cert"`
+	Insecure bool   `json:"insecure"`
+}
+
+func (to TcpOptions) CheckValid() error {
+	if to.Host == "" && to.IP == "" {
+		return errors.New("missing host")
+	}
+	if to.Port == 0 {
+		return errors.New("missing port")
+	}
+	return nil
+}
+
+// NewTcpTarget creates a target capable of outputting log records to a raw socket, with or without TLS.
+func NewTcpTarget(options *TcpOptions) *Tcp {
+	tcp := &Tcp{
+		options:  options,
+		addy:     fmt.Sprintf("%s:%d", options.IP, options.Port),
+		monitor:  make(chan struct{}),
+		shutdown: make(chan struct{}),
+	}
+	return tcp
+}
+
+// Init is called once to initialize the target.
+func (tcp *Tcp) Init() error {
+	return nil
+}
+
+// getConn provides a net.Conn.  If a connection already exists, it is returned immediately,
+// otherwise this method blocks until a new connection is created, timeout or shutdown.
+func (tcp *Tcp) getConn(reporter func(err interface{})) (net.Conn, error) {
+	tcp.mutex.Lock()
+	defer tcp.mutex.Unlock()
+
+	if tcp.conn != nil {
+		return tcp.conn, nil
+	}
+
+	type result struct {
+		conn net.Conn
+		err  error
+	}
+
+	connChan := make(chan result)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*DialTimeoutSecs)
+	defer cancel()
+
+	go func(ctx context.Context, ch chan result) {
+		conn, err := tcp.dial(ctx)
+		if err != nil {
+			reporter(fmt.Errorf("log target %s connection error: %w", tcp.String(), err))
+			return
+		}
+		tcp.conn = conn
+		tcp.monitor = make(chan struct{})
+		go monitor(tcp.conn, tcp.monitor)
+		ch <- result{conn: conn, err: err}
+	}(ctx, connChan)
+
+	select {
+	case <-tcp.shutdown:
+		return nil, errors.New("shutdown")
+	case res := <-connChan:
+		return res.conn, res.err
+	}
+}
+
+// dial connects to a TCP socket, and optionally performs a TLS handshake.
+// A non-nil context must be provided which can cancel the dial.
+func (tcp *Tcp) dial(ctx context.Context) (net.Conn, error) {
+	var dialer net.Dialer
+	dialer.Timeout = time.Second * DialTimeoutSecs
+	conn, err := dialer.DialContext(ctx, "tcp", fmt.Sprintf("%s:%d", tcp.options.IP, tcp.options.Port))
+	if err != nil {
+		return nil, err
+	}
+
+	if !tcp.options.TLS {
+		return conn, nil
+	}
+
+	tlsconfig := &tls.Config{
+		ServerName:         tcp.options.IP,
+		InsecureSkipVerify: tcp.options.Insecure,
+	}
+	if tcp.options.Cert != "" {
+		pool, err := GetCertPool(tcp.options.Cert)
+		if err != nil {
+			return nil, err
+		}
+		tlsconfig.RootCAs = pool
+	}
+
+	tlsConn := tls.Client(conn, tlsconfig)
+	if err := tlsConn.Handshake(); err != nil {
+		return nil, err
+	}
+	return tlsConn, nil
+}
+
+func (tcp *Tcp) close() error {
+	tcp.mutex.Lock()
+	defer tcp.mutex.Unlock()
+
+	var err error
+	if tcp.conn != nil {
+		close(tcp.monitor)
+		err = tcp.conn.Close()
+		tcp.conn = nil
+	}
+	return err
+}
+
+// Shutdown stops processing log records after making best effort to flush queue.
+func (tcp *Tcp) Shutdown() error {
+	err := tcp.close()
+	close(tcp.shutdown)
+	return err
+}
+
+// Write converts the log record to bytes, via the Formatter, and outputs to the socket.
+// Called by dedicated target goroutine and will block until success or shutdown.
+func (tcp *Tcp) Write(p []byte, rec *logr.LogRec) (int, error) {
+	try := 1
+	backoff := RetryBackoffMillis
+	for {
+		select {
+		case <-tcp.shutdown:
+			return 0, nil
+		default:
+		}
+
+		reporter := rec.Logger().Logr().ReportError
+
+		conn, err := tcp.getConn(reporter)
+		if err != nil {
+			reporter(fmt.Errorf("log target %s connection error: %w", tcp.String(), err))
+			backoff = tcp.sleep(backoff)
+			continue
+		}
+
+		err = conn.SetWriteDeadline(time.Now().Add(time.Second * WriteTimeoutSecs))
+		if err != nil {
+			reporter(fmt.Errorf("log target %s set write deadline error: %w", tcp.String(), err))
+		}
+
+		count, err := conn.Write(p)
+		if err == nil {
+			return count, nil
+		}
+
+		reporter(fmt.Errorf("log target %s write error: %w", tcp.String(), err))
+
+		_ = tcp.close()
+
+		backoff = tcp.sleep(backoff)
+		try++
+	}
+}
+
+// monitor continuously tries to read from the connection to detect socket close.
+// This is needed because TCP target uses a write only socket and Linux systems
+// take a long time to detect a loss of connectivity on a socket when only writing;
+// the writes simply fail without an error returned.
+func monitor(conn net.Conn, done <-chan struct{}) {
+	buf := make([]byte, 1)
+	for {
+		select {
+		case <-done:
+			return
+		case <-time.After(1 * time.Second):
+		}
+
+		err := conn.SetReadDeadline(time.Now().Add(time.Second * 30))
+		if err != nil {
+			continue
+		}
+
+		_, err = conn.Read(buf)
+
+		if errt, ok := err.(net.Error); ok && errt.Timeout() {
+			// read timeout is expected, keep looping.
+			continue
+		}
+
+		// Any other error closes the connection, forcing a reconnect.
+		conn.Close()
+		return
+	}
+}
+
+// String returns a string representation of this target.
+func (tcp *Tcp) String() string {
+	return fmt.Sprintf("TcpTarget[%s:%d]", tcp.options.IP, tcp.options.Port)
+}
+
+func (tcp *Tcp) sleep(backoff int64) int64 {
+	select {
+	case <-tcp.shutdown:
+	case <-time.After(time.Millisecond * time.Duration(backoff)):
+	}
+
+	nextBackoff := backoff + (backoff >> 1)
+	if nextBackoff > MaxRetryBackoffMillis {
+		nextBackoff = MaxRetryBackoffMillis
+	}
+	return nextBackoff
+}