Chkconfig alternative for Ubuntu Server?

The equivalent to chkconfig is update-rc.d

The equivalents you seek are

update-rc.d <service> defaults
update-rc.d <service> start 20 3 4 5
update-rc.d -f <service>  remove

See this useful page for more information or check out man update-rc.d

Best alternative IMHO is sysv-rc-conf To install just need to run the command:

sudo apt-get install sysv-rc-conf

Once installed run the command:

sudo sysv-rc-conf

You can check or uncheck the options to start a service on any level of execution and may even stop or start the services from this console. It is an indispensable tool to enable or disable applications on an permanently way to boot your ubuntu If you need a quick change, then you can use the CLI interface:

For example to stop ssh at levels 3 and 5 of execution:

sysv-rc-conf-off level 35 ssh

Atd to start in runlevels 2,3,4 and 5:

sysv-rc-conf on atd

If you want to know more:

man sysv-rc-conf

Right now, there is no equivalent on a stable release for doing things with Upstart scripts. Jacob Peddicord wrote jobservice (backend daemon) and jobs-admin (GTK+ GUI that talks to it) for his Google Summer of Code project. Lucid packages are in his PPA. They also exist in Universe in Maverick. There is no command line front-end for jobservice yet, just jobs-admin.