LXC execution, something’s not right yet

I’ve complained about some LXC choices last week, but at the same time I was working on at least trying to get it to run, somewhat, so that I could make use of it on our required setup.

The result has been a new revbump of LXC (0.8.0_rc1-r1), which contains a patch using libtool to build the library, this also makes sure that the library is properly created with an always-variable soname (see the link for more explanation on what that is).

This new version actually allows you to go one step further, and you can properly set it to execute commands within the container, directly. Even though it takes a bit of time due to the POSIX Message Queue not being extremely fast (Luca do you know anything about that?). The problem is that if you’re going to run any interactive command.. you get stuck, almost literally, including a very simple emerge -av.

The problem, as far as I can tell, is that the namespacing allows the container to create a new pseudo-tty (PTS) within the container itself, instead of using the one that is connected with the current session. This means that you cannot actually use the tty at all, making it impossible to run any kind of interactive command (at the same time, it doesn’t make it known to the command that it lacks a controlling tty, so for instance an emerge -av does not get downgraded to emerge -pv this way.

I’m hoping that maybe Kevin’s (whichever Kevin that is!) patches mentioned in my previous post will help getting it to work, if so that would also mean that the tinderbox would be much easier to deal with than it has been in the past, and might actually get me to restore it to a working state (it hasn’t been working for a quite long time at this point, and I’m certainly not happy about it).

For the moment what I can tell is that I’ve half-tracked down the issue with the netprio cgroup, and contacted its original author to see how we can deal with it, and I have a couple of changes for the ebuild and init scripts queued up. Since at least the cgroup mountpoint issue has been fixed in the utilities, I’ll soon make it depend on a version of OpenRC new enough to mount the thing by itself, easing off part of the init script log (well, to be honest I’ve already dropped most of that logic), so that it can actually grow from there…

I guess I should thank Tiziano for telling me about LXC at the time, although there is still so much work to do before it works as intended. Oh well.

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