message: nydus-image: add bootstrap path to build output
  Add bootstrap path to build output.
diff: @@ -64,6 +64,8 @@ const BLOB_ID_MAXIMUM_LENGTH: usize = 255;
  pub struct OutputSerializer {
  /// The binary version of builder (nydus-image).
  version: String,
  + /// RAFS meta data file path.
  + bootstrap: String,
  /// Represents all blob in blob table ordered by blob index, this field
  /// only include the layer that does have a blob, and should be deprecated
  /// in future, use `artifacts` field to replace.
  @@ -93,6 +95,7 @@ impl OutputSerializer {
  let version = format!("{}-{}", build_info.package_ver, build_info.git_commit);
  let output = Self {
  version,
  + bootstrap: build_output.bootstrap_path.unwrap_or_default(),
  blobs: build_output.blobs,
  trace,
  };
  @@ -107,6 +110,7 @@ impl OutputSerializer {
  matches: &clap::ArgMatches,
  build_info: &BuildTimeInfo,
  blob_ids: Vec<String>,
  + bootstrap: &Path,
  ) -> Result<()> {
  let output_json: Option<PathBuf> = matches
  .get_one::<String>("output-json")
  @@ -123,6 +127,7 @@ impl OutputSerializer {
  let version = format!("{}-{}", build_info.package_ver, build_info.git_commit);
  let output = Self {
  version,
  + bootstrap: bootstrap.display().to_string(),
  blobs: blob_ids,
  trace,
  };
  @@ -866,7 +871,7 @@ impl Command {
  blob_ids.push(blob.blob_id().to_string());
  }
  - OutputSerializer::dump_with_check(matches, build_info, blob_ids)?;
  + OutputSerializer::dump_with_check(matches, build_info, blob_ids, bootstrap_path)?;
  Ok(())
  }
  