third party config support

# Conflicts:
#	internal/config/config.go
#	internal/config/types.go
#	internal/file/file_manager_service.go

Author: Akshay2191

internal/file/file_manager_service.go

@@ -410,12 +410,12 @@ func (fms *FileManagerService) DetermineFileActions(
 		// If it's external, we DON'T care about disk state or hashes here.
 		// We tag it as ExternalFile and let the downloader handle the rest.
 		if modifiedFile.File.GetExternalDataSource() != nil || (ok && currentFile.GetExternalDataSource() != nil) {
-			slog.DebugContext(ctx, "External file URI detected - flagging for fetch", "file_name", fileName)
+			slog.DebugContext(ctx, "External file detected - flagging for fetch", "file_name", fileName)
 			modifiedFile.Action = model.ExternalFile
 			fileDiff[fileName] = modifiedFile
 			continue
 		}
-		
+
 		// If file currently exists on disk, is being tracked in manifest and file hash is different.
 		// Treat it as a file update.
 		if ok && modifiedFile.File.GetFileMeta().GetHash() != currentFile.GetFileMeta().GetHash() {
@@ -468,7 +468,6 @@ func (fms *FileManagerService) DetermineFileActions(
 	return fileDiff, nil
 }
 
-
 // UpdateCurrentFilesOnDisk updates the FileManagerService currentFilesOnDisk slice which contains the files
 // currently on disk
 func (fms *FileManagerService) UpdateCurrentFilesOnDisk(

internal/file/file_service_operator.go

@@ -285,6 +285,23 @@ func (fso *FileServiceOperator) UpdateFile(
 	return fso.sendUpdateFileStream(ctx, fileToUpdate, fso.agentConfig.Client.Grpc.FileChunkSize)
 }
 
+func (fso *FileServiceOperator) RenameExternalFile(
+	ctx context.Context, source, desination string,
+) error {
+	slog.DebugContext(ctx, fmt.Sprintf("Moving file %s to %s (no hash validation)", source, desination))
+
+	if err := os.MkdirAll(filepath.Dir(desination), dirPerm); err != nil {
+		return fmt.Errorf("failed to create directories for %s: %w", desination, err)
+	}
+
+	moveErr := os.Rename(source, desination)
+	if moveErr != nil {
+		return fmt.Errorf("failed to move file: %w", moveErr)
+	}
+
+	return nil
+}
+
 // renameFile, renames (moves) file from tempDir to new location to update file.
 func (fso *FileServiceOperator) RenameFile(
 	ctx context.Context, source, desination string,

internal/model/config.go

@@ -52,6 +52,10 @@ type ManifestFileMeta struct {
 	Referenced bool `json:"referenced"`
 	// File is not managed by the agent
 	Unmanaged bool `json:"unmanaged"`
+	// ETag of the 3rd Party external file
+	ETag string `json:"etag"`
+	// Last modified time of the 3rd Party external file
+	LastModified string `json:"last_modified"`
 }
 type ConfigApplyMessage struct {
 	Error         error