How do you set a program as a service in Linux (Debian) but have it switched off by default?

Question

When you install Alfresco, it gives you an option of having it installed as a service or not.

If you install it as a service, the service starts up on booting but since it's using Tomcat it's too heavy to leave as a background program. In addition, it takes a lot longer to stop than Apache.

Therefore, I would like to keep it as a service but have it set to off by default so all I need to do is type sudo service alfresco start.

While I can leave it set-up not as a service and write a bash script or two, I'd like to learn more about how "services" work in Linux. Apache's not a problem but it would be nice to know where its service parameters are stored and how you can change these.

Answer 1

The 'general' approach would be

$ sudo update-rc.d -f servicename remove

to remove the servicename from any runlevel to start automatically.

To re-enable the defaults, do

$ sudo update-rc.d servicename defaults

Answer 2

You could use sysv-rc-conf to manage runlevels (configure which services are supposed to be started at which runlevels).

It is quite simple:

1. Install it: sudo apt-get install sysv-rc-conf
2. Run it: sudo sysv-rc-conf
3. Mark your service to be started on desired runlevels (2, 3, 4 and 5 are regular boot, 0 is shutdown, 6 is reboot). Use keyboard arrows to navigate and space key to toggle a checkbox.

Answer 3

By default, Debian ships with SysVinit. Which services are executed in which runlevels is controlled through symbolic links in /etc/initN.d (N = 0 to 6, with 2–5 being the normal runlevels; S is for services started at boot time). See Dmitry Vasilyanov and gertvdijk's answers for ways of configuring these symbolic links.

I like to use the file-rc package, which replaces the symbolic links with a simple text file /etc/runlevel.conf.

If you're going to turn off a lot of services, or if you want to prevent a service from starting when it's installed or upgraded (a known issue on Debian), you can define a local service start policy. Write a script called /usr/sbin/policy-rc.d that implements the init script policy of your choice. See /usr/share/doc/sysv-rc/README.policy-rc.d on your system for details. Implementing a full policy is a bit of work, but you can make simple cases work; for example, if the script just contains exit 101, then no init script will ever be executed (this is convenient for systems installed in a chroot).