Upstart 0.9 now replaces (x)inetd!

The upcoming version of Ubuntu, version 11.04 code name "natty", will include Upstart 0.9 which brings a very nifty trick (from http://www.ubuntu.com/testing/natty/alpha3):

Upstart now provides a socket bridge (upstart-socket-bridge) which is a daemon started early in the boot process that allows jobs to be started when socket connections are made. Jobs register their desire to be started by a socket connection by requiring the new "socket" event in their start on (or stop on) stanza(s):


# Internet sockets
start on socket PROTO=PROTO PORT=PORT ADDR=ADDR

# Local and Abstract sockets
socket PROTO=PROTO PATH=PATH

For example, to have a web server only start when the first client connection is received, its job configuration file might specify:


start on socket PROTO=inet PORT=80

See the new manual pages for further details:

• upstart-socket-event (7)
  
• upstart-socket-bridge (8)