Add hooks to genkernel

[Dissonant-Tech]

Possible solution to #61

[mudler]

Thanks! i like the idea of having configurable hooks, and i ack for completeness: if we have to provide this feature should be complete in each phase (as you did).

But i do think that needs to be documented (since we already lack it in some areas)

[Dissonant-Tech]

But i do think that needs to be documented

@mudler Not a problem! I'm taking a look at doc/genkernel.8.txt to see where the docs would fit but I'm not too sure. Should there be a new category or under an old one? And if so, where would that category fit?

From what I can tell the best places would either be:

1. HOOKS category between ACTIONS and OPTIONS
2. HOOKS category before NETBOOTING
3. Documentation under ACTIONS since the available actions correlate pretty well with the available hooks.

In any case it will consist of a bit of info on how the hooks work (running all executable scripts in a certain directory) plus a list of available hooks.

Just let me know what sounds best and I'll get on that.

[mudler]

to me looks fine either way 👍 , feel free to pick one - even tho i'm inclined for 2) since it's a new feature, but 3) sounds also fair as well

[Dissonant-Tech]

@mudler I ended up going for 2) as suggested, and in the end I think it was the right option. Let me know if you feel there is anything else missing.

[mudler]

Thanks! 👍