sync with README

Upstream-commit: 9875a9b1f1b59114356c129f42449e2d62427f65
Component: engine

components/engine/docs/sources/commandline/basics.rst

@@ -69,7 +69,8 @@ Expose a service on a TCP port
 
   # Connect to the public port via the host's public address
   # Please note that because of how routing works connecting to localhost or 127.0.0.1 $PORT will not work.
-  echo hello world | nc $(hostname) $PORT
+  IP=$(ifconfig eth0 | perl -n -e 'if (m/inet addr:([\d\.]+)/g) { print $1 }')
+  echo hello world | nc $IP $PORT
 
   # Verify that the network connection worked
   echo "Daemon received: $(docker logs $JOB)"