libminifi/include/c2/protocols/RESTSender.h

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#pragma once

#include <string>
#include <memory>
#include <vector>
#include <optional>

#include "c2/C2Protocol.h"
#include "c2/protocols/RESTProtocol.h"
#include "minifi-cpp/controllers/SSLContextServiceInterface.h"
#include "http/HTTPClient.h"
#include "utils/Enum.h"

namespace org::apache::nifi::minifi::c2 {

/**
 * Purpose and Justification: Encapsulates the restful protocol that is built upon C2Protocol.
 *
 * The external interfaces rely solely on send, where send includes a Direction. Transmit will perform a POST
 * and RECEIVE will perform a GET. This does not mean we can't receive on a POST; however, since Direction
 * will encompass other protocols the context of its meaning here simply translates into POST and GET respectively.
 *
 */
class RESTSender : public RESTProtocol, public C2Protocol {
 public:
  enum class RequestEncoding {
    none,
    gzip
  };

  explicit RESTSender(std::string_view name, const utils::Identifier &uuid = utils::Identifier());

  MINIFIAPI static constexpr const char* Description = "Encapsulates the restful protocol that is built upon C2Protocol.";

  C2Payload consumePayload(const std::string &url, const C2Payload &payload, Direction direction, bool async) override;

  C2Payload consumePayload(const C2Payload &payload, Direction direction, bool async) override;

  bool fetch(const std::string& url, const std::vector<std::string>& accepted_formats, std::function<bool(std::span<const char> chunk)> chunk_callback) override;

  void update(const std::shared_ptr<Configure> &configure) override;

  void initialize(core::controller::ControllerServiceProvider* controller, const std::shared_ptr<Configure> &configure) override;

 protected:
  C2Payload sendPayload(const std::string& url, const Direction direction, const C2Payload &payload, std::optional<std::string> data,
                        const std::optional<std::vector<std::string>>& accepted_formats = std::nullopt);

  /**
   * Initializes the SSLContextService onto the HTTP client if one is needed
   * @param client HTTP client
   * @param type type of HTTP request
   * @param url HTTP url
   */
  void setSecurityContext(http::HTTPClient &client, http::HttpRequestMethod type, const std::string &url);

  std::shared_ptr<minifi::controllers::SSLContextServiceInterface> ssl_context_service_;

  std::string rest_uri_;
  std::string ack_uri_;
  RequestEncoding req_encoding_ = RequestEncoding::none;

 private:
  std::chrono::milliseconds asset_download_timeout_{0};
  std::shared_ptr<core::logging::Logger> logger_ = core::logging::LoggerFactory<RESTSender>::getLogger();
};

}  // namespace org::apache::nifi::minifi::c2