[lxc-devel] [RFC] lxc-start: daemonize by default

[Christian Seiler]

Hi there,

First of all, thanks for the feedback, it appears I'm not alone in
wishing that LXC changes this behavior. :-)

>> It has been several times that I have accidentally run lxc-start
>> without the -d flag and then had to shut the container down again
>> only to immediately try again with -d. Therefore, at least from
>> the way I use LXC, it seems to me to be much more sensible to
>> have lxc-start daemonize by default and instead provide flag to
>> keep it in the foreground, which seems to be a use case that is
>> rare in comparison.
>>
>> Obviously, this shouldn't be done for the 1.0 branch, since this
>> breaks the given interface. But could we think about this for
>> the next release (or, if you want to be conservative, the
>> release after that with a warning in the next)? Thoughts?
>>
>> Regards,
>> Christian
> 
> And make -F mean 'foreground a console'?

I don't quite know what you mean by 'foreground a console'. To clear a
few things up, I want to mention a use case for the current current
default behavior that I have:

lxc-start -n foo -- /bin/bash /tmp/post_container_create_actions
(called from a script that also captures output)

Obviously, if you mean by 'foreground a console' that it's the same
behavior as currently, so that the above works if I just add a -F, I'm
all for it. If you mean something else, please elaborate. :)



My suggestion (if you see it the same way I do) would be that I write
three patches:

1. First patch adds a -F option for keeping stuff in the foreground. In
this patch, it is simply ignored. This patch can then be backported to
1.0 in order to create early compatibility.

2. Second patch changes default behavior to -d but keeps -d (just does
nothing anymore). This then should NOT be backported.

3. Third patch changes daemonize behavior of LXC to wait until the
container has left the STARTING state (either RUNNING or some failure),
and use an apropriate exit code. This might be backported, or not.

If there's consensus, I'll get on that.

Regards,
Christian

PS: Btw. I've really, really come to like the -f option of lxc-ls.
Thanks to whoever implemented that.