Re: interesting claims

2019-04-30 Thread Jonathan de Boyne Pollard

Jeff:


where can i learn how a "correct" init has to operate ?



See https://unix.stackexchange.com/a/197472/5132 for starters.


Re: interesting claims

2019-04-30 Thread Laurent Bercot

"suckless init is incorrect, because it has no supervision capabilities,
and thus, killing all processes but init can brick the machine."

a rather bold claim IMO !
where was the "correct" init behaviour specified ?
where can i learn how a "correct" init has to operate ?


For instance:
https://archive.fosdem.org/2017/schedule/event/s6_supervision/
https://www.youtube.com/watch?v=I7qE43KK5bY=7591
 
https://www.reddit.com/r/linux/comments/2dx7k3/s6_skarnetorg_small_secure_supervision_software/cjxc1hj/?context=3


 Or, as Guillermo mentioned, several posts in the ML archive.

 init is a subject that little study has been put into (though it
is also the subject of a whole lot of talk, which says something
about whether people would rather talk or study). But I think you'll
find that things are different around here.



or is it true since s6-svscan already provides such respawn
capabilities ? ;-)


Do not mistake causes for consequences. Things are not correct
because s6 does them; s6 does things because they are correct.



there is actually NO need for a "correct" working init implementation
to provide respawn capabilities at all IMO.


Then you are free to use one of the many incorrect inits out there,
including sinit, Rich Felker's init, dumb-init, and others. You are
definitely not alone with your opinion. However, you sound interested
in process supervision, which is part of the more general idea that a
machine should be made as reliable as possible *at all times* and
*under any circumstances*; if you subscribe to that idea, then you
will understand why init must supervise at least 1 process.



so this looks like a rather artificial and constructed argument for
the necessity of respawn functionality in an init implementation IMO.


 Maybe you've never bricked a device because init didn't respawn
anything. I have. The "rather artificial and constructed argument"
happened to me in real life, and it was a significant inconvenience.

--
 Laurent