Re: using upstart in Debian
Dmitrijs Ledkovs <xnox@debian.org> writes:
>> Also on technical merits although more philosophically, with Upstart you're
>> expressing yourself in an event-based DSL rather than writing configuration
>> files. It's pretty generic. But unfortunately, that means it's also not
>> entirely straightforward, and, I believe, easier to get wrong. Scott had
>> some explaining blog posts before he left Canonical that I still find
>> confusing (from the POV of just getting a job file done):
>>
>> http://netsplit.com/2010/12/20/events-are-like-methods/
>> http://netsplit.com/2010/12/03/event-matching-in-upstart/
>>
>
> Since those blog posts were published a coprehensive documentation
> book was written and is constantly kept up to date.
>
> http://upstart.ubuntu.com/cookbook/
>
> It actually guides & explains upstart concepts in a coherent and
> straight-forward manner with a very large section of examples on how
> to achieve various goals & tasks.
It is well documented, but IMO doesn't make it any less counterintuitive
and confusing.
For example: after some intense studying, I now fully understand why
declaring a new upstart job C that depends on existing jobs A and B
("start on job-a-did-its-thing AND job-b-did-its-thing") may prevent the
start of job A (cf https://bugs.launchpad.net/ubuntu/+source/upstart/+bug/964207).
However, I still consider it confusing and at least questionable design that
adding a new job can prevent an existing job from starting even though
they do not conflict in any way.
Moreover, understanding this has actually made me even more nervous
about configuring upstart jobs. This is issue is not something that I
was able to pick up routinely from reading the documentation, so I'm
always worried that there might be similar issues I'm not yet aware of,
even though they can (in principle) be derived and explained from the
documentation.
Best,
-Nikolaus
--
»Time flies like an arrow, fruit flies like a Banana.«
PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6 02CF A9AD B7F8 AE4E 425C
Reply to: