Documentation
¶
Overview ¶
Package proxy provides a reverse proxy handler for gRPC.
The implementation allows a `grpc.Server` to pass a received ServerStream to a ClientStream without understanding the semantics of the messages exchanged. It basically provides a transparent reverse-proxy.
This package is intentionally generic, exposing a `StreamDirector` function that allows users of this package to implement whatever logic of backend-picking, dialing and service verification to perform.
Package is a revised version of https://github.com/mwitkow/grpc-proxy
Index ¶
- func Codec() codec
- func CodecWithParent(fallback encoding.Codec) codec
- func RegisterService(server *grpc.Server, director StreamDirector, serviceName string, ...)
- func RegisterTestServiceServer(s *grpc.Server, srv TestServiceServer)
- func TransparentHandler(director StreamDirector) grpc.StreamHandler
- type Empty
- type PingRequest
- type PingResponse
- type StreamDirector
- type TestServiceClient
- type TestServiceServer
- type TestService_PingListClient
- type TestService_PingListServer
- type TestService_PingStreamClient
- type TestService_PingStreamServer
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Codec ¶
func Codec() codec
Codec returns a proxying codec with conforms both to encoding.Codec and grpc.Codec with the default protobuf codec as parent.
See CodecWithParent.
func CodecWithParent ¶
CodecWithParent returns a proxying encoding.Codec with a user provided codec as parent.
This codec is *crucial* to the functioning of the proxy. It allows the proxy server to be oblivious to the schema of the forwarded messages. It basically treats a gRPC message frame as raw bytes. However, if the server handler, or the client caller are not proxy-internal functions it will fall back to trying to decode the message using a fallback codec.
func RegisterService ¶
func RegisterService(server *grpc.Server, director StreamDirector, serviceName string, methodNames ...string)
func RegisterTestServiceServer ¶
func RegisterTestServiceServer(s *grpc.Server, srv TestServiceServer)
func TransparentHandler ¶
func TransparentHandler(director StreamDirector) grpc.StreamHandler
TransparentHandler returns a handler that attempts to proxy all requests that are not registered in the server. The indented use here is as a transparent proxy, where the server doesn't know about the services implemented by the backends. It should be used as a `grpc.UnknownServiceHandler`.
This can *only* be used if the `server` also uses proxy.CustomCodec(proxy.Codec()) ServerOption.
Types ¶
type Empty ¶
type Empty struct {
}
func (*Empty) Descriptor ¶
func (*Empty) ProtoMessage ¶
func (*Empty) ProtoMessage()
type PingRequest ¶
type PingRequest struct {
Value string `protobuf:"bytes,1,opt,name=value" json:"value,omitempty"`
}
func (*PingRequest) Descriptor ¶
func (*PingRequest) Descriptor() ([]byte, []int)
func (*PingRequest) GetValue ¶
func (m *PingRequest) GetValue() string
func (*PingRequest) ProtoMessage ¶
func (*PingRequest) ProtoMessage()
func (*PingRequest) Reset ¶
func (m *PingRequest) Reset()
func (*PingRequest) String ¶
func (m *PingRequest) String() string
type PingResponse ¶
type PingResponse struct {
Value string `protobuf:"bytes,1,opt,name=Value" json:"Value,omitempty"`
Counter int32 `protobuf:"varint,2,opt,name=counter" json:"counter,omitempty"`
}
func (*PingResponse) Descriptor ¶
func (*PingResponse) Descriptor() ([]byte, []int)
func (*PingResponse) GetCounter ¶
func (m *PingResponse) GetCounter() int32
func (*PingResponse) GetValue ¶
func (m *PingResponse) GetValue() string
func (*PingResponse) ProtoMessage ¶
func (*PingResponse) ProtoMessage()
func (*PingResponse) Reset ¶
func (m *PingResponse) Reset()
func (*PingResponse) String ¶
func (m *PingResponse) String() string
type StreamDirector ¶
type StreamDirector func(ctx context.Context, fullMethodName string) (outgoingContext context.Context, backendConn *grpc.ClientConn, err error)
StreamDirector returns a gRPC ClientConn to be used to forward the call to.
The presence of the `Context` allows for rich filtering, e.g. based on Metadata (headers). If no handling is meant to be done, a `codes.NotImplemented` gRPC error should be returned.
The context returned from this function should be the context for the *outgoing* (to backend) call. In case you want to forward any Metadata between the inbound request and outbound requests, you should do it manually. However, you *must* propagate the cancel function (`context.WithCancel`) of the inbound context to the one returned.
It is worth noting that the StreamDirector will be fired *after* all server-side stream interceptors are invoked. So decisions around authorization, monitoring etc. are better to be handled there.
type TestServiceClient ¶
type TestServiceClient interface {
PingEmpty(ctx context.Context, in *Empty, opts ...grpc.CallOption) (*PingResponse, error)
Ping(ctx context.Context, in *PingRequest, opts ...grpc.CallOption) (*PingResponse, error)
PingError(ctx context.Context, in *PingRequest, opts ...grpc.CallOption) (*Empty, error)
PingList(ctx context.Context, in *PingRequest, opts ...grpc.CallOption) (TestService_PingListClient, error)
PingStream(ctx context.Context, opts ...grpc.CallOption) (TestService_PingStreamClient, error)
}
func NewTestServiceClient ¶
func NewTestServiceClient(cc *grpc.ClientConn) TestServiceClient
type TestServiceServer ¶
type TestServiceServer interface {
PingEmpty(context.Context, *Empty) (*PingResponse, error)
Ping(context.Context, *PingRequest) (*PingResponse, error)
PingError(context.Context, *PingRequest) (*Empty, error)
PingList(*PingRequest, TestService_PingListServer) error
PingStream(TestService_PingStreamServer) error
}
type TestService_PingListClient ¶
type TestService_PingListClient interface {
Recv() (*PingResponse, error)
grpc.ClientStream
}
type TestService_PingListServer ¶
type TestService_PingListServer interface {
Send(*PingResponse) error
grpc.ServerStream
}
type TestService_PingStreamClient ¶
type TestService_PingStreamClient interface {
Send(*PingRequest) error
Recv() (*PingResponse, error)
grpc.ClientStream
}
type TestService_PingStreamServer ¶
type TestService_PingStreamServer interface {
Send(*PingResponse) error
Recv() (*PingRequest, error)
grpc.ServerStream
}
Source Files