Method _httpCheck

src/checks/checker_process.cpp:1033–1090

Future<int> CheckerProcess::_httpCheck(
    const vector<string>& cmdArgv,
    const Option<runtime::Plain>& plain)
{
  VLOG(1) << "Launching " << name << " with command '"
          << strings::join(" ", cmdArgv) << "' for task '" << taskId << "'";

  // TODO(alexr): Consider launching the helper binary once per task lifetime,
  // see MESOS-6766.
  Try<Subprocess> s = process::subprocess(
      cmdArgv[0],
      cmdArgv,
      Subprocess::PATH(os::DEV_NULL),
      Subprocess::PIPE(),
      Subprocess::PIPE(),
      nullptr,
      None(),
      getCustomCloneFunc(plain));

  if (s.isError()) {
    return Failure(
        "Failed to create the " + string(HTTP_CHECK_COMMAND) +
        " subprocess: " + s.error());
  }

  // TODO(alexr): Use lambda named captures for
  // these cached values once it is available.
  const pid_t curlPid = s->pid();
  const string _name = name;
  const Duration timeout = checkTimeout;
  const TaskID _taskId = taskId;

  return await(
      s->status(),
      process::io::read(s->out().get()),
      process::io::read(s->err().get()))
    .after(
        timeout,
        [timeout, curlPid, _name, _taskId](Future<tuple<Future<Option<int>>,
                                                        Future<string>,
                                                        Future<string>>> future)
    {
      future.discard();

      if (curlPid != -1) {
        // Cleanup the HTTP_CHECK_COMMAND process.
        VLOG(1) << "Killing the " << _name << " process " << curlPid
                << " for task '" << _taskId << "'";

        os::killtree(curlPid, SIGKILL);
      }

      return Failure(
          string(HTTP_CHECK_COMMAND) + " timed out after " +
          stringify(timeout));
    })
    .then(defer(self(), &Self::__httpCheck, lambda::_1));
}