Re: [gentoo-dev] rc-scripts/init: new service dependency

[Daniel]

On Wed, 7 May 2003 09:26 am, Wout Mertens wrote:
>
> 1) semi-hardcoded:
> - put a bunch of SysV init style symlinks to initscripts in
>   /etc/conf.d/net.d/ifup.d/
> - the interface comes up
> - start/stop each of them in order, with $INTERFACE set to the interface,
>
> Pro: Easy to write, the user has full control over what gets started or
> stopped
>
> Con: hard to maintain the SysV init style directory, each event needs a
> directory, solves only one problem.
>
> 2) event based:
> - the initscripts put subscribe statements in their depend() code
> - the interface comes up
> - the event dispatcher runs the subscribed initscripts event() functions,
>   with details about the event (who, what and args).
>
> Pro: Easy to write the initscripts, solves many problems. The event
> dispatcher shouldn't be difficult.
>
> Con: Need to find a nice way for a user to disable an initscript, so it
> doesn't get events. Example: the net may be up, but the user doesn't want
> wwwoffle to be brought online.
>
>
> Wout.
>

Expanding (combining?, bastardising (hopefully not)) your ideas:

SysV init style scripts in /etc/netinit.d

Have /etc/netlevel directory (akin to /etc/runlevels) with the subdirectories 
representing the interface e.g /etc/netlevel/ppp0 /etc/netlevel/eth0 and 
possibly a sepecial /etc/netlevel/all (called for any interface going up or 
down).

Could have a user interface in the form of:
"rc-netupdate {add|del} firewall ppp0"

Aguement to these scripts could be "start"."stop" as usual. Additionaly 
"reconfig" for example if the network interface parmeter change (IP change) 
with the details of the change in environment variables (IP_OLD,IP_NEW, etc). 
I think it would be hard to make all permutations of network change in a 
generic command line format. Are there any other generic  events that need to 
occur?

These would be called upon the hotplug events or /etc/ppp/ip-{up-down} since 
as you mentioned a generic interface is getting hard. I mentioned 
ip-{up|down} because of the case of dial-on-demand and 
/etc/init.d/net.{interface} does not necessarly bring up the interface. If 
its a simple interface the could be called from the /etc/init.d/net.* script 
through some function.

This solves your con of having all events is a different direcory. Scripts are 
now subscription based and triggered by "events".

Taking into account the hotplug usb device mount idea - a few find and 
replaces "s/net/event/g" and replace net interface directories with 
"/etc/eventlevel.d/net.{interface}" and the predominate mechanism is the 
same. I'm not too familiar with hotplug so appoligies if this is unfesable.

Ok "evenlevel" sounds sucky but how does the framework sound.


Daniel
-- 
Key fingerprint = 2300 3292 3351 9665 D41B DC20 4C34 9BB6 32A6 4DC8


--
gentoo-dev@g.o mailing list