fix: guard all R2 operations behind nil client checks for local dev support

backend/playout/src/playlist.go

@@ -59,8 +59,21 @@ const (
 	manifestCacheControl = "public, max-age=1, s-maxage=2, must-revalidate"
 )
 
-// initR2Client initializes the R2 (S3-compatible) client
+// isR2Configured returns true when the required R2 environment variables are set.
+func isR2Configured() bool {
+	return os.Getenv("R2_ENDPOINT") != "" &&
+		os.Getenv("R2_ACCESS_KEY_ID") != "" &&
+		os.Getenv("R2_SECRET_ACCESS_KEY") != "" &&
+		os.Getenv("R2_BUCKET_NAME") != ""
+}
+
+// initR2Client initializes the R2 (S3-compatible) client.
+// Returns an error if required environment variables are missing.
 func initR2Client() error {
+	if !isR2Configured() {
+		return fmt.Errorf("R2 not configured: R2_ENDPOINT, R2_ACCESS_KEY_ID, R2_SECRET_ACCESS_KEY, or R2_BUCKET_NAME is empty")
+	}
+
 	cfg, err := config.LoadDefaultConfig(context.TODO(),
 		config.WithRegion("auto"),
 		config.WithCredentialsProvider(aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
@@ -566,10 +579,9 @@ func main() {
 		os.Exit(1)
 	}
 
-	// Initialize R2 client
+	// Initialize R2 client (skip if not configured — local HLS via nginx still works)
 	if err := initR2Client(); err != nil {
-		fmt.Println("Warning: R2 client initialization failed:", err)
-		// Continue without R2 for local testing
+		fmt.Println("R2 sync disabled:", err)
 	}
 
 	// Start HTTP health check server
@@ -612,9 +624,14 @@ func main() {
 			continue
 		}
 
-		// Start filesystem watcher for real-time R2 segment upload (STREAMING.md)
-		watchCtx, watchCancel := context.WithCancel(context.Background())
-		go watchAndPublishSegments(watchCtx, hlsDir)
+		// Start filesystem watcher for real-time R2 segment upload (STREAMING.md).
+		// Only active when R2 is configured; otherwise the watcher is skipped.
+		var watchCtx context.Context
+		var watchCancel context.CancelFunc
+		if r2Client != nil {
+			watchCtx, watchCancel = context.WithCancel(context.Background())
+			go watchAndPublishSegments(watchCtx, hlsDir)
+		}
 
 		fmt.Printf("[%s] Starting FFmpeg playout with browser-safe H.264/AAC HLS encoding...\n", time.Now().Format(time.RFC3339))
 
@@ -635,7 +652,9 @@ func main() {
 			filepath.Join(hlsDir, "playlist.m3u8"))
 
 		runErr := cmd.Run()
-		watchCancel() // Stop the filesystem watcher
+		if watchCancel != nil {
+			watchCancel() // Stop the filesystem watcher
+		}
 
 		// Track restart and check for slate escalation
 		restartCount++
@@ -659,15 +678,18 @@ func main() {
 			deactivateSlate()
 		}
 
-		// After FFmpeg run, publish remaining segments and atomic manifest to R2
-		if err := syncLatestToR2(hlsDir); err != nil {
-			fmt.Println("R2 sync warning:", err)
-		}
+		// After FFmpeg run, publish remaining segments and atomic manifest to R2.
+		// Skipped when R2 is not configured.
+		if r2Client != nil {
+			if err := syncLatestToR2(hlsDir); err != nil {
+				fmt.Println("R2 sync warning:", err)
+			}
 
-		// Publish manifest atomically (STREAMING.md safe publication)
-		manifestPath := filepath.Join(hlsDir, "playlist.m3u8")
-		if err := publishManifest(manifestPath); err != nil {
-			fmt.Println("Manifest publish warning:", err)
+			// Publish manifest atomically (STREAMING.md safe publication)
+			manifestPath := filepath.Join(hlsDir, "playlist.m3u8")
+			if err := publishManifest(manifestPath); err != nil {
+				fmt.Println("Manifest publish warning:", err)
+			}
 		}
 
 		time.Sleep(5 * time.Second)