Init : someone could comment this ?

[Les Mikesell]

Andrew Farris wrote:

>> What is missing IMVHO is the ability of handling service dependencies, 
>> but
>> that one is very tricky. For example, it mostly makes no sense to run a
>> mail/web/... server if there is no network, but the minority of cases 
>> where
>> it does make sense is sizeable nonetheless. And trying to cater for both
>> cases rapidly gets to be an unmanageable mess.
> 
> What should be discussed are only serious *requirements* in the init 
> scripts dependencies.  In the example you gave here it makes no sense to 
> prevent the web server from running because of no network because it 
> could serve a purpose and it does function that way (and can be turned 
> off if the user did not want it running).

What happens in practice, though, is that things that expect network 
services to be running will do DNS lookups, hanging for minutes at at 
time when there is no response.

 > A dependency should be only
> what is absolutely required for basic functionality so that if it is 
> turned on it has the *capability of starting*. It should be a much more 
> manageable mess when the bare bones basics are figured out.

Things may be 'capable' of starting with a several-minute timeout and 
failing DNS but that doesn't mean it is desirable - or that they will 
necessarily work when the interface(s) the services were supposed to be 
listening on become active later.  On the other hand, you may have 
nothing but a loopback interface and a hosts file and want things to 
come up running so you can test them locally, or in sendmail's case so 
it can accept local submissions.

And in the case of a laptop, it is fairly likely that you'll want to 
suspend it on one network (wired/wireless or both) and wake it up on 
something different.

-- 
    Les Mikesell
     lesmikesell at gmail.com