From: GOTOU Yuuzou <gotoyuzo@...>
Date: 2005-03-21T04:36:12+09:00
Subject: Re: can WEBrick bind to port 0, and then tell me what port was allocated?

Hi,

In message <20050320184914.GB911@ensemble.local>,
 `Sam Roberts <sroberts@uniserve.com>' wrote:
> INADDR_ANY with a port of zero. The system will select a free port.
> 
> Then, I can advertise that port using mDNS/DNS-SD.
> 
> Is this possible? I can maybe set :Port to 0, but I am searching the
> webrick src and can't see a way to get the underlying socket up, so I
> can ask it it's port.

Setting :Port to 0 works like you want. However WEBrick
never report it. I think the log messages should be changed.
How about the following patch?

--- lib/webrick/server.rb	7 Mar 2005 12:32:07 -0000	1.9
+++ lib/webrick/server.rb	20 Mar 2005 19:17:49 -0000
@@ -74,11 +78,16 @@     def listen(address, port)
 
     def start(&block)
       raise ServerError, "already started." if @status != :Stop
       server_type = @config[:ServerType] || SimpleServer
 
       server_type.start{
-        @logger.info \
-          "#{self.class}#start: pid=#{$$} port=#{@config[:Port]}"
+        @logger.info "#{self.class}#start: pid=#{$$}"
+        @listeners.each{|sock|
+          sockaddr = sock.addr
+          addr = sockaddr[3]
+          port = sockaddr[1]
+          @logger.info "#{self.class}#start: addr=#{addr} port=#{port}"
+        }
         call_callback(:StartCallback)
 
         thgroup = ThreadGroup.new

-- 
gotoyuzo