pullImage method

Future<void> pullImage(String image)

Downloads image from its registry, waiting for the end of the pull; its progress is ignored.

Throws a DockerException saying which image could not be pulled and why (a name or tag that does not exist, a registry that asks for a login). Registry credentials are not sent: private images must be pulled beforehand (docker login, docker pull).

Implementation

Future<void> pullImage(String image) async {
  final (name, tag) = parseImage(image);
  final HttpClientResponse response;
  try {
    response = await _send(
      'POST',
      '/images/create',
      query: {'fromImage': name, 'tag': ?tag},
    );
  } on DockerException catch (e) {
    throw DockerException(
      "Cannot pull the image '$image': ${e.message}",
      statusCode: e.statusCode,
    );
  }
  // The progress is a stream of JSON lines; a failure is one of them.
  await for (final line
      in response.transform(utf8.decoder).transform(const LineSplitter())) {
    if (line.trim().isEmpty) {
      continue;
    }
    final Object? event;
    try {
      event = jsonDecode(line);
    } on FormatException {
      continue;
    }
    if (event is Map<String, Object?> && event['error'] != null) {
      throw DockerException(
        "Cannot pull the image '$image': ${event['error']}",
      );
    }
  }
}