feat: add debug mode for Unix socket output

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

README.md

@@ -231,6 +231,7 @@ outputs:
     enabled: true
     params:
       socket_path: /var/run/logcorrelator/network.socket
+      # debug: true  # Activer pour logger l'état de connexion et les données envoyées
 ```
 
 ### Logging fichier + stdout

config.yml.example

@@ -36,3 +36,4 @@ outputs:
   #   enabled: false
   #   params:
   #     socket_path: /var/run/logcorrelator/network.socket
+  #     debug: true  # Enable debug logging for socket connection state

internal/output/writers.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log"
 	"net"
 	"os"
 	"path/filepath"
@@ -197,6 +198,8 @@ type UnixSocketWriter struct {
 	isClosed          bool
 	pendingWrites     [][]byte
 	pendingMu         sync.Mutex
+	debug             bool
+	logger            *log.Logger
 }
 
 // NewUnixSocketWriter creates a new UNIX socket writer with reconnection logic
@@ -206,6 +209,11 @@ func NewUnixSocketWriter(socketPath string) (*UnixSocketWriter, error) {
 
 // NewUnixSocketWriterWithConfig creates a new UNIX socket writer with custom configuration
 func NewUnixSocketWriterWithConfig(socketPath string, dialTimeout, writeTimeout time.Duration, queueSize int) (*UnixSocketWriter, error) {
+	return NewUnixSocketWriterWithConfigAndDebug(socketPath, dialTimeout, writeTimeout, queueSize, false, nil)
+}
+
+// NewUnixSocketWriterWithConfigAndDebug creates a new UNIX socket writer with debug logging
+func NewUnixSocketWriterWithConfigAndDebug(socketPath string, dialTimeout, writeTimeout time.Duration, queueSize int, debug bool, logger *log.Logger) (*UnixSocketWriter, error) {
 	w := &UnixSocketWriter{
 		socketPath:       socketPath,
 		dialTimeout:      dialTimeout,
@@ -217,6 +225,8 @@ func NewUnixSocketWriterWithConfig(socketPath string, dialTimeout, writeTimeout
 		queueClose:       make(chan struct{}),
 		queueDone:        make(chan struct{}),
 		pendingWrites:    make([][]byte, 0),
+		debug:            debug,
+		logger:           logger,
 	}
 
 	// Start the queue processor
@@ -226,6 +236,13 @@ func NewUnixSocketWriterWithConfig(socketPath string, dialTimeout, writeTimeout
 	conn, err := net.DialTimeout("unix", socketPath, w.dialTimeout)
 	if err == nil {
 		w.conn = conn
+		if w.debug && w.logger != nil {
+			w.logger.Printf("[DEBUG] UnixSocketWriter: connected to %s", socketPath)
+		}
+	} else {
+		if w.debug && w.logger != nil {
+			w.logger.Printf("[DEBUG] UnixSocketWriter: initial connection to %s failed: %v (will retry on write)", socketPath, err)
+		}
 	}
 
 	return w, nil
@@ -256,6 +273,10 @@ func (w *UnixSocketWriter) processQueue() {
 				}
 				w.pendingMu.Unlock()
 
+				if w.debug && w.logger != nil {
+					w.logger.Printf("[DEBUG] UnixSocketWriter: write failed to %s: %v (failures: %d)", w.socketPath, err, consecutiveFailures)
+				}
+
 				// Exponential backoff
 				if consecutiveFailures > w.maxReconnects {
 					time.Sleep(backoff)
@@ -265,6 +286,9 @@ func (w *UnixSocketWriter) processQueue() {
 					}
 				}
 			} else {
+				if w.debug && w.logger != nil {
+					w.logger.Printf("[DEBUG] UnixSocketWriter: wrote %d bytes to %s", len(data), w.socketPath)
+				}
 				consecutiveFailures = 0
 				backoff = w.reconnectBackoff
 				// Try to flush pending data
@@ -312,10 +336,16 @@ func (w *UnixSocketWriter) writeWithReconnect(data []byte) error {
 			return fmt.Errorf("failed to connect to socket %s: %w", w.socketPath, err)
 		}
 		w.conn = conn
+		if w.debug && w.logger != nil {
+			w.logger.Printf("[DEBUG] UnixSocketWriter: reconnected to %s", w.socketPath)
+		}
 		return nil
 	}
 
 	if err := ensureConn(); err != nil {
+		if w.debug && w.logger != nil {
+			w.logger.Printf("[DEBUG] UnixSocketWriter: connection failed to %s: %v", w.socketPath, err)
+		}
 		return err
 	}
 
@@ -328,6 +358,9 @@ func (w *UnixSocketWriter) writeWithReconnect(data []byte) error {
 	}
 
 	// Connection failed, try to reconnect
+	if w.debug && w.logger != nil {
+		w.logger.Printf("[DEBUG] UnixSocketWriter: write failed, attempting reconnect to %s", w.socketPath)
+	}
 	_ = w.conn.Close()
 	w.conn = nil
 
@@ -386,6 +419,9 @@ func (w *UnixSocketWriter) Close() error {
 
 		w.isClosed = true
 		if w.conn != nil {
+			if w.debug && w.logger != nil {
+				w.logger.Printf("[DEBUG] UnixSocketWriter: closing connection to %s", w.socketPath)
+			}
 			w.conn.Close()
 			w.conn = nil
 		}
@@ -482,7 +518,14 @@ func (b *BuilderImpl) NewFromConfig(cfg api.AppConfig) (api.Writer, error) {
 			if socketPath == "" {
 				return nil, fmt.Errorf("unix_socket output requires 'socket_path' parameter")
 			}
-			writer, err = NewUnixSocketWriter(socketPath)
+			// Check for debug mode
+			debug := outputCfg.Params["debug"] == "true" || outputCfg.Params["debug"] == "1"
+			if debug {
+				logger := log.New(os.Stderr, "[UnixSocket] ", log.LstdFlags|log.Lmicroseconds)
+				writer, err = NewUnixSocketWriterWithConfigAndDebug(socketPath, DefaultDialTimeout, DefaultWriteTimeout, DefaultQueueSize, debug, logger)
+			} else {
+				writer, err = NewUnixSocketWriter(socketPath)
+			}
 			if err != nil {
 				return nil, err
 			}