title: Port Unification in grpc-java
body: <p>I am looking for an approach to enable SSL on demand for gRPC.</p>
  <p><a href="https://netty.io/4.1/xref/io/netty/example/portunification/package-summary.html" rel="nofollow noreferrer">Netty doc</a> shows this can be done by adding a custom <em>ByteToMessageDecoder</em> handler, reading through the initial bytes, and making decisions on the fly.</p>
  <p>Does grpc-java support port unification? From my initial dig at the code, the <a href="https://github.com/grpc/grpc-java/blob/master/netty/src/main/java/io/grpc/netty/NettyServer.java#L228" rel="nofollow noreferrer">server-starter</a> doesn't seem to expose any interface to inject custom handlers.</p>