Function executeFileOperation

src/slave/containerizer/mesos/launch.cpp:487–559

static Try<Nothing> executeFileOperation(const ContainerFileOperation& op)
{
  switch (op.operation()) {
    case ContainerFileOperation::SYMLINK: {
      Try<Nothing> result =
        ::fs::symlink(op.symlink().source(), op.symlink().target());
      if (result.isError()) {
        return Error(
            "Failed to link '" + op.symlink().source() + "' as '" +
            op.symlink().target() + "': " + result.error());
      }

      return Nothing();
    }

    case ContainerFileOperation::MOUNT: {
#ifdef __linux__
      Try<Nothing> result = mountContainerFilesystem(op.mount());
      if (result.isError()) {
        return Error(
            "Failed to mount '" + stringify(JSON::protobuf(op.mount())) +
            "': " + result.error());
      }

      return Nothing();
#else
      return Error("Container mount is not supported on non-Linux systems");
#endif // __linux__
    }

    case ContainerFileOperation::RENAME: {
      Try<Nothing> result =
        os::rename(op.rename().source(), op.rename().target());

      // TODO(jpeach): We should only fall back to `mv` if the error
      // is EXDEV, in which case a rename is a copy+unlink.
      if (result.isError()) {
        Option<int> status = os::spawn(
            "mv", {"mv", "-f", op.rename().source(), op.rename().target()});

        if (status.isNone()) {
          return Error(
              "Failed to rename '" + op.rename().source() + "' to '" +
              op.rename().target() + "':  spawn failed");
        }

        if (!WSUCCEEDED(status.get())) {
          return Error(
              "Failed to rename '" + op.rename().source() + "' to '" +
              op.rename().target() + "': " + WSTRINGIFY(status.get()));
        }

        result = Nothing();
      }

      return Nothing();
  }