Butler stream servers can generate client address.

logdog/client/butler/streamserver/streamserver.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package streamserver
 
 import (
         "io"
 
         "github.com/luci/luci-go/logdog/client/butlerlib/streamproto"
 )
 
 // StreamServer is an interface to a backgound service that allows external
 // processes to establish Butler streams.
 type StreamServer interface {
         // Performs initial connection and setup, entering a listening state.
         Listen() error
+
+        // Address returns a string that can be used by the "streamclient" package to
+        // return a client for this StreamServer.
+        //
+        // Full package is:
+        // github.com/luci/luci-go/logdog/butlerlib/streamclient
+        //
+        // Address may only be called while the StreamServer is actively listening.
+        Address() string
+
         // Blocks, returning a new Stream when one is available. If the stream server
         // has closed, this will return nil.
         Next() (io.ReadCloser, *streamproto.Properties)
+
         // Closes the stream server, cleaning up resources.
         Close()
 }