Switch from Unix sockets to TCP for Docker Desktop compatibility

Architecture:
- Container acts as TCP server (listens on :5151)
- Windows binary connects as TCP client
- Same protocol: newline-delimited JSON

Usage:
  docker run -p 5151:5151 -v C:\src:/host:ro -v data:/data sourcewatch
  sourcewatch.exe -dir C:\src -connect localhost:5151

This avoids Docker Desktop's inability to mount Windows Unix sockets
into Linux containers (they become directories instead of files).

1 files changed, 29 insertions, 26 deletions

diff --git a/cmd_linux.go b/cmd_linux.go
index 65e8644..069881a 100644
--- a/cmd_linux.go
+++ b/cmd_linux.go
@@ -15,10 +15,10 @@ import (
 )
 
 var (
-	hostDir    = flag.String("host", "/host", "Host source directory (read-only)")
-	dataDir    = flag.String("data", "/data", "Data destination directory")
-	dryRun     = flag.Bool("dry-run", false, "Preview what would be synced without copying")
-	socketPath = flag.String("socket", "/run/sourcewatch.sock", "Unix socket to receive events from (Windows watcher)")
+	hostDir  = flag.String("host", "/host", "Host source directory (read-only)")
+	dataDir  = flag.String("data", "/data", "Data destination directory")
+	dryRun   = flag.Bool("dry-run", false, "Preview what would be synced without copying")
+	listen   = flag.String("listen", ":5151", "TCP address to listen on for Windows watcher connections")
 )
 
 func run() {
@@ -40,8 +40,8 @@ func run() {
 
 	stack := NewGitignoreStack(*hostDir)
 
-	if *socketPath == "" {
-		logInfo("no -socket specified, running standalone (full scan)")
+	if *listen == "" {
+		logInfo("no -listen specified, running standalone (full scan)")
 		manifest, err := initialSync(*hostDir, *dataDir, stack, *dryRun)
 		if err != nil {
 			logErrorf("initial sync failed: %v", err)
@@ -57,29 +57,35 @@ func run() {
 		return
 	}
 
-	logInfo("watcher: connecting to %s ...", *socketPath)
+	ln, err := net.Listen("tcp", *listen)
+	if err != nil {
+		logErrorf("listen: %v", err)
+		os.Exit(1)
+	}
+	defer ln.Close()
+
+	logInfo("watcher: listening on %s", *listen)
+	logInfo("watcher: waiting for Windows watcher to connect ...")
 
-	var conn net.Conn
 	for {
 		if ctx.Err() != nil {
-			logErrorf("cancelled while connecting")
-			os.Exit(1)
-		}
-		conn, err = net.Dial("unix", *socketPath)
-		if err == nil {
-			break
+			return
 		}
-		logDebug("connect failed: %v, retrying...", err)
-		select {
-		case <-ctx.Done():
-			logErrorf("cancelled while connecting")
-			os.Exit(1)
-		case <-time.After(1 * time.Second):
+
+		conn, err := ln.Accept()
+		if err != nil {
+			logErrorf("accept: %v", err)
+			continue
 		}
+
+		logInfo("watcher: client connected from %s", conn.RemoteAddr())
+		handleClient(conn, stack)
+		logInfo("watcher: client disconnected, waiting for reconnect ...")
 	}
-	defer conn.Close()
+}
 
-	logInfo("watcher: connected, receiving manifest ...")
+func handleClient(conn net.Conn, stack *GitignoreStack) {
+	defer conn.Close()
 
 	scanner := bufio.NewScanner(conn)
 	remoteManifest := &Manifest{Files: make(map[string]FileMeta)}
@@ -134,7 +140,7 @@ func run() {
 	}
 
 	if err := scanner.Err(); err != nil {
-		logErrorf("socket read: %v", err)
+		logErrorf("read: %v", err)
 	}
 }
 
@@ -142,7 +148,6 @@ func syncFromManifest(remote *Manifest, stack *GitignoreStack) {
 	stats := &syncStats{}
 	start := time.Now()
 
-	// Scan local /data to get current state (fast, local volume)
 	localManifest := scanLocalDirectory(*dataDir)
 
 	for relPath, remoteMeta := range remote.Files {
@@ -157,7 +162,6 @@ func syncFromManifest(remote *Manifest, stack *GitignoreStack) {
 		destPath := filepath.Join(*dataDir, relPath)
 		srcPath := filepath.Join(*hostDir, relPath)
 
-		// Check if file already exists locally with same metadata
 		if localMeta, exists := localManifest.Files[relPath]; exists {
 			if localMeta.Size == remoteMeta.Size &&
 				localMeta.Mode == remoteMeta.Mode &&
@@ -167,7 +171,6 @@ func syncFromManifest(remote *Manifest, stack *GitignoreStack) {
 			}
 		}
 
-		// Need to sync
 		info, err := os.Lstat(srcPath)
 		if err != nil {
 			if os.IsNotExist(err) {