Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include <memory>
       4             : #include <string>
       5             : 
       6             : #include "envoy/common/pure.h"
       7             : #include "envoy/http/message.h"
       8             : #include "envoy/upstream/cluster_manager.h"
       9             : 
      10             : #include "source/common/http/message_impl.h"
      11             : #include "source/extensions/common/aws/utility.h"
      12             : 
      13             : #include "absl/strings/string_view.h"
      14             : #include "absl/types/optional.h"
      15             : 
      16             : namespace Envoy {
      17             : namespace Extensions {
      18             : namespace Common {
      19             : namespace Aws {
      20             : 
      21             : class MetadataFetcher;
      22             : using MetadataFetcherPtr = std::unique_ptr<MetadataFetcher>;
      23             : 
      24             : /**
      25             :  * MetadataFetcher interface can be used to retrieve AWS Metadata from various providers.
      26             :  * An instance of this interface is designed to retrieve one AWS Metadata at a time.
      27             :  * The implementation of AWS Metadata Fetcher is similar to JwksFetcher.
      28             :  */
      29             : 
      30             : class MetadataFetcher {
      31             : public:
      32             :   class MetadataReceiver {
      33             :   public:
      34             :     enum class Failure {
      35             :       /* A network error occurred causing AWS Metadata retrieval failure. */
      36             :       Network,
      37             :       /* A failure occurred when trying to parse the retrieved AWS Metadata data. */
      38             :       InvalidMetadata,
      39             :       /* A missing config causing AWS Metadata retrieval failure. */
      40             :       MissingConfig,
      41             :     };
      42             : 
      43           6 :     virtual ~MetadataReceiver() = default;
      44             : 
      45             :     /**
      46             :      * @brief Successful retrieval callback of returned AWS Metadata.
      47             :      * @param body Fetched AWS Metadata.
      48             :      */
      49             :     virtual void onMetadataSuccess(const std::string&& body) PURE;
      50             : 
      51             :     /**
      52             :      * @brief Retrieval error callback.
      53             :      * @param reason the failure reason.
      54             :      */
      55             :     virtual void onMetadataError(Failure reason) PURE;
      56             :   };
      57             : 
      58           0 :   virtual ~MetadataFetcher() = default;
      59             : 
      60             :   /**
      61             :    * @brief Cancel any in-flight request.
      62             :    */
      63             :   virtual void cancel() PURE;
      64             : 
      65             :   /**
      66             :    * @brief Retrieve a AWS Metadata from a remote HTTP host.
      67             :    * At most one outstanding request may be in-flight.
      68             :    * i.e. from the invocation of `fetch()` until either
      69             :    * a callback or `cancel()` is invoked, no additional
      70             :    * `fetch()` may be issued. The URI to fetch is to pre
      71             :    * determined based on the credentials provider source.
      72             :    *
      73             :    * @param receiver the receiver of the fetched AWS Metadata or error
      74             :    */
      75             :   virtual void fetch(Http::RequestMessage& message, Tracing::Span& parent_span,
      76             :                      MetadataReceiver& receiver) PURE;
      77             : 
      78             :   /**
      79             :    * @brief Return MetadataReceiver Failure enum as a string.
      80             :    *
      81             :    * @return absl::string_view
      82             :    */
      83             :   virtual absl::string_view failureToString(MetadataReceiver::Failure) PURE;
      84             : 
      85             :   /**
      86             :    * @brief Factory method for creating a Metadata Fetcher.
      87             :    *
      88             :    * @param cm the cluster manager to use during AWS Metadata retrieval
      89             :    * @param provider the AWS Metadata provider
      90             :    * @return a MetadataFetcher instance
      91             :    */
      92             :   static MetadataFetcherPtr create(Upstream::ClusterManager& cm, absl::string_view cluster_name);
      93             : };
      94             : } // namespace Aws
      95             : } // namespace Common
      96             : } // namespace Extensions
      97             : } // namespace Envoy