Method reserve

src/master/http.cpp:1832–1928

Future<Response> Master::Http::reserve(
    const Request& request,
    const Option<Principal>& principal) const
{
  // TODO(greggomann): Remove this check once the `Principal` type is used in
  // `ReservationInfo`, `DiskInfo`, and within the master's `principals` map.
  // See MESOS-7202.
  if (principal.isSome() && principal->value.isNone()) {
    return Forbidden(
        "The request's authenticated principal contains claims, but no value "
        "string. The master currently requires that principals have a value");
  }

  // When current master is not the leader, redirect to the leading master.
  if (!master->elected()) {
    return redirect(request);
  }

  if (request.method != "POST") {
    return MethodNotAllowed({"POST"}, request.method);
  }

  // Parse the query string in the request body.
  Try<hashmap<string, string>> decode =
    process::http::query::decode(request.body);

  if (decode.isError()) {
    return BadRequest("Unable to decode query string: " + decode.error());
  }

  // Helper function to parse a list of resource from query parameters.
  auto parseResourcesList = [](
      const std::string& key,
      const hashmap<string, string>& queryParameters)
    -> Try<RepeatedPtrField<Resource>>
    {
      Option<string> value = queryParameters.get(key);
      if (value.isNone()) {
        return Error(
          "Missing '" + key + "' query parameter in the request body");
      }

      Try<JSON::Array> parse =
        JSON::parse<JSON::Array>(value.get());

      if (parse.isError()) {
        return Error(
            "Error parsing '" + key +
            "' query parameter in the request body: " + parse.error());
      }

      RepeatedPtrField<Resource> resources;
      foreach (const JSON::Value& value, parse->values) {
        Try<Resource> resource = ::protobuf::parse<Resource>(value);
        if (resource.isError()) {
          return Error(
              "Error parsing '" + key +
              "' query parameter in the request body: " + resource.error());