github.com/gravitational/teleport/api@v0.0.0-20240507183017-3110591cbafc/breaker/interceptors.go (about)

     1  // Copyright 2022 Gravitational, Inc
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package breaker
    16  
    17  import (
    18  	"context"
    19  
    20  	"google.golang.org/grpc"
    21  )
    22  
    23  // UnaryClientInterceptor is a unary gRPC client interceptor that uses the provided CircuitBreaker to track errors
    24  // returned from the outgoing calls.
    25  func UnaryClientInterceptor(cb *CircuitBreaker) grpc.UnaryClientInterceptor {
    26  	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
    27  		_, err := cb.Execute(func() (interface{}, error) {
    28  			err := invoker(ctx, method, req, reply, cc, opts...)
    29  			return nil, err
    30  		})
    31  		return err
    32  	}
    33  }
    34  
    35  // StreamClientInterceptor is a stream gRPC client interceptor that uses the provided CircuitBreaker to track errors
    36  // returned from the outgoing calls.
    37  func StreamClientInterceptor(cb *CircuitBreaker) grpc.StreamClientInterceptor {
    38  	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
    39  		stream, err := cb.Execute(func() (interface{}, error) {
    40  			return streamer(ctx, desc, cc, method, opts...)
    41  		})
    42  
    43  		if stream == nil {
    44  			return nil, err
    45  		}
    46  
    47  		if cs, ok := stream.(grpc.ClientStream); ok {
    48  			return cs, err
    49  		}
    50  
    51  		return nil, err
    52  	}
    53  }