redfish_passthrough_plugin.h

#pragma once

#include <memory>

#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "redfish_query_engine/http/client.h"
#include "http_client_pool.h"
#include "proxy_config.pb.h"
#include "redfish_plugin.h"
#include "request_response.h"

namespace milotic {

// Implements backend of RedfishPlugin, sending requests as http.
// HandleRequest runs synchronously, but can be called by multiple threads
// simultaneously after initialization.
// Example:
//    RedfishPlugin *redfish_plugin = new RedfishPassthroughPlugin();
//    redfish_plugin->Initialize("localhost:8889");
//    absl::Status status = redfish_plugin->HandleRequest(
//        RedfishPlugin::RequestVerb::Get,
//        request,
//        response);
//    return status;
class RedfishPassthroughPluginBase : public RedfishPlugin {
 protected:
  RedfishPassthroughPluginBase(ecclesia::HttpClient* http_client,
                               ecclesia::HttpClient* subscribe_http_client)
      : http_client_(*http_client),
        subscribe_http_client_(*subscribe_http_client) {}

 public:
  virtual ~RedfishPassthroughPluginBase() = default;

  RequestAction PreprocessRequest(RedfishPlugin::RequestVerb verb,
                                  ProxyRequest& /*request*/) override {
    if (verb == RedfishPlugin::RequestVerb::kInternal) {
      return RequestAction::kDrop;
    }
    return RequestAction::kHandle;
  }

  absl::StatusOr<ProxyResponse> HandleRequest(
      RedfishPlugin::RequestVerb verb,
      std::unique_ptr<ProxyRequest> request) override;

  absl::Status Subscribe(std::unique_ptr<ProxyRequest> /*request*/,
                         EventHandler* handler) override;

  absl::Status Initialize(Proxy* /*proxy*/) override;

  RedfishPassthroughPluginBase(const RedfishPassthroughPluginBase&) = delete;
  RedfishPassthroughPluginBase& operator=(const RedfishPassthroughPluginBase&) =
      delete;

 private:
  ecclesia::HttpClient& http_client_;
  ecclesia::HttpClient& subscribe_http_client_;
};

class RedfishPassthroughPlugin : public RedfishPassthroughPluginBase {
 public:
  explicit RedfishPassthroughPlugin(
      const milotic_grpc_proxy::Plugin::RedfishPassthrough& config);

 private:
  HttpClientPool curl_http_client_;
  HttpClientPool subscribe_curl_http_client_;
};

}  // namespace milotic