cockroachdb/cmux

Name: cmux

Owner: CockroachDB

Description: Connection multiplexer for GoLang: serve different services on the same port!

Forked from: soheilhy/cmux

Created: 2016-02-28 18:40:05.0

Updated: 2018-05-11 07:27:30.0

Pushed: 2017-01-10 19:26:08.0

Homepage:

Size: 72

Language: Go

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README

cmux: Connection Mux

cmux is a generic Go library to multiplex connections based on their payload. Using cmux, you can serve gRPC, SSH, HTTPS, HTTP, Go RPC, and pretty much any other protocol on the same TCP listener.

How-To

Simply create your main listener, create a cmux for that listener, and then match connections:

reate the main listener.
rr := net.Listen("tcp", ":23456")
rr != nil {
log.Fatal(err)


reate a cmux.
 cmux.New(l)

atch connections in order:
irst grpc, then HTTP, and otherwise Go RPC/TCP.
L := m.Match(cmux.HTTP2HeaderField("content-type", "application/grpc"))
L := m.Match(cmux.HTTP1Fast())
L := m.Match(cmux.Any()) // Any means anything that is not yet matched.

reate your protocol servers.
S := grpc.NewServer()
hello.RegisterGreeterServer(grpcs, &server{})

S := &http.Server{
Handler: &helloHTTP1Handler{},


S := rpc.NewServer()
gister(&ExampleRPCRcvr{})

se the muxed listeners for your servers.
rpcS.Serve(grpcL)
ttpS.Serve(httpL)
rpcS.Accept(trpcL)

tart serving!
rve()

There are more examples on GoDoc.

Performance

Since we are only matching the very first bytes of a connection, the performance overhead on long-lived connections (i.e., RPCs and pipelined HTTP streams) is negligible.

Limitations

• TLS: net/http uses a type assertion to identify TLS connections; since cmux's lookahead-implementing connection wraps the underlying TLS connection, this type assertion fails. This means you can serve HTTPS using cmux but http.Request.TLS will not be set in your handlers. If you are able to wrap TLS around cmux, you can work around this limitation. See https://github.com/cockroachdb/cockroach/commit/83caba2 for an example of this approach.

• Different Protocols on The Same Connection: cmux matches the connection when it's accepted. For example, one connection can be either gRPC or REST, but not both. That is, we assume that a client connection is either used for gRPC or REST.

Copyright and License

Copyright 2016 The CMux Authors. All rights reserved.

See CONTRIBUTORS for the CMux Authors. Code is released under the Apache 2 license.