Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include "envoy/common/pure.h"
       4             : #include "envoy/config/core/v3/http_uri.pb.h"
       5             : #include "envoy/upstream/cluster_manager.h"
       6             : 
       7             : namespace Envoy {
       8             : namespace Config {
       9             : namespace DataFetcher {
      10             : 
      11             : /**
      12             :  * Failure reason.
      13             :  */
      14             : enum class FailureReason {
      15             :   /* A network error occurred causing remote data retrieval failure. */
      16             :   Network,
      17             :   /* A failure occurred when trying to verify remote data using sha256. */
      18             :   InvalidData,
      19             : };
      20             : 
      21             : /**
      22             :  * Callback used by remote data fetcher.
      23             :  */
      24             : class RemoteDataFetcherCallback {
      25             : public:
      26           0 :   virtual ~RemoteDataFetcherCallback() = default;
      27             : 
      28             :   /**
      29             :    * This function will be called when data is fetched successfully from remote.
      30             :    * @param data remote data
      31             :    */
      32             :   virtual void onSuccess(const std::string& data) PURE;
      33             : 
      34             :   /**
      35             :    * This function is called when error happens during fetching data.
      36             :    * @param reason failure reason.
      37             :    */
      38             :   virtual void onFailure(FailureReason reason) PURE;
      39             : };
      40             : 
      41             : /**
      42             :  * Remote data fetcher.
      43             :  */
      44             : class RemoteDataFetcher : public Logger::Loggable<Logger::Id::config>,
      45             :                           public Http::AsyncClient::Callbacks {
      46             : public:
      47             :   RemoteDataFetcher(Upstream::ClusterManager& cm, const envoy::config::core::v3::HttpUri& uri,
      48             :                     const std::string& content_hash, RemoteDataFetcherCallback& callback);
      49             : 
      50             :   ~RemoteDataFetcher() override;
      51             : 
      52             :   // Http::AsyncClient::Callbacks
      53             :   void onSuccess(const Http::AsyncClient::Request&, Http::ResponseMessagePtr&& response) override;
      54             :   void onFailure(const Http::AsyncClient::Request&,
      55             :                  Http::AsyncClient::FailureReason reason) override;
      56             :   void onBeforeFinalizeUpstreamSpan(Envoy::Tracing::Span&,
      57           0 :                                     const Http::ResponseHeaderMap*) override {}
      58             : 
      59             :   /**
      60             :    * Fetch data from remote.
      61             :    * @param uri remote URI
      62             :    * @param content_hash for verifying data integrity
      63             :    * @param callback callback when fetch is done.
      64             :    */
      65             :   void fetch();
      66             : 
      67             :   /**
      68             :    * Cancel the fetch.
      69             :    */
      70             :   void cancel();
      71             : 
      72             : private:
      73             :   Upstream::ClusterManager& cm_;
      74             :   const envoy::config::core::v3::HttpUri uri_;
      75             :   const std::string content_hash_;
      76             :   RemoteDataFetcherCallback& callback_;
      77             : 
      78             :   Http::AsyncClient::Request* request_{};
      79             : };
      80             : 
      81             : using RemoteDataFetcherPtr = std::unique_ptr<RemoteDataFetcher>;
      82             : 
      83             : } // namespace DataFetcher
      84             : } // namespace Config
      85             : } // namespace Envoy