1 // 2 // Copyright 2023 gRPC authors. 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // http://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 // 16 17 #ifndef GRPC_SRC_CORE_UTIL_GCP_METADATA_QUERY_H 18 #define GRPC_SRC_CORE_UTIL_GCP_METADATA_QUERY_H 19 20 #include <grpc/support/port_platform.h> 21 22 #include <string> 23 24 #include "absl/functional/any_invocable.h" 25 #include "absl/status/statusor.h" 26 #include "src/core/lib/iomgr/closure.h" 27 #include "src/core/lib/iomgr/error.h" 28 #include "src/core/lib/iomgr/polling_entity.h" 29 #include "src/core/util/http_client/httpcli.h" 30 #include "src/core/util/http_client/parser.h" 31 #include "src/core/util/orphanable.h" 32 #include "src/core/util/time.h" 33 34 namespace grpc_core { 35 36 // Fetches the value of an attribute from the MetadataServer on a GCP 37 // environment. 38 class GcpMetadataQuery : public InternallyRefCounted<GcpMetadataQuery> { 39 public: 40 static constexpr const char kZoneAttribute[] = 41 "/computeMetadata/v1/instance/zone"; 42 static constexpr const char kClusterNameAttribute[] = 43 "/computeMetadata/v1/instance/attributes/cluster-name"; 44 static constexpr const char kRegionAttribute[] = 45 "/computeMetadata/v1/instance/region"; 46 static constexpr const char kInstanceIdAttribute[] = 47 "/computeMetadata/v1/instance/id"; 48 static constexpr const char kIPv6Attribute[] = 49 "/computeMetadata/v1/instance/network-interfaces/0/ipv6s"; 50 51 GcpMetadataQuery( 52 std::string attribute, grpc_polling_entity* pollent, 53 absl::AnyInvocable<void(std::string /* attribute */, 54 absl::StatusOr<std::string> /* result */)> 55 callback, 56 Duration timeout); 57 58 // Alternative ctor allows overriding the metadata server address, mainly 59 // to inject fakes in tests 60 GcpMetadataQuery( 61 std::string metadata_server_name, std::string attribute, 62 grpc_polling_entity* pollent, 63 absl::AnyInvocable<void(std::string /* attribute */, 64 absl::StatusOr<std::string> /* result */)> 65 callback, 66 Duration timeout); 67 68 ~GcpMetadataQuery() override; 69 70 void Orphan() override; 71 72 private: 73 static void OnDone(void* arg, grpc_error_handle error); 74 75 grpc_closure on_done_; 76 std::string attribute_; 77 absl::AnyInvocable<void(std::string /* attribute */, 78 absl::StatusOr<std::string> /* result */)> 79 callback_; 80 OrphanablePtr<HttpRequest> http_request_; 81 grpc_http_response response_; 82 }; 83 84 } // namespace grpc_core 85 86 #endif // GRPC_SRC_CORE_UTIL_GCP_METADATA_QUERY_H 87