On Thu, 2020-07-02 at 21:10 +0200, Christian Brauner wrote: > On Thu, Jul 02, 2020 at 08:17:38AM -0500, Eric W. Biederman wrote: > > Matt Bennett <matt.bennett@xxxxxxxxxxxxxxxxxxx> writes: > > > > > Previously the connector functionality could only be used by processes running in the > > > default network namespace. This meant that any process that uses the connector functionality > > > could not operate correctly when run inside a container. This is a draft patch series that > > > attempts to now allow this functionality outside of the default network namespace. > > > > > > I see this has been discussed previously [1], but am not sure how my changes relate to all > > > of the topics discussed there and/or if there are any unintended side effects from my draft > > > changes. > > > > Is there a piece of software that uses connector that you want to get > > working in containers? We have an IPC system [1] where processes can register their socket details (unix, tcp, tipc, ...) to a 'monitor' process. Processes can then get notified when other processes they are interested in start/stop their servers and use the registered details to connect to them. Everything works unless a process crashes, in which case the monitoring process never removes their details. Therefore the monitoring process uses the connector functionality with PROC_EVENT_EXIT to detect when a process crashes and removes the details if it is a previously registered PID. This was working for us until we tried to run our system in a container. > > > > I am curious what the motivation is because up until now there has been > > nothing very interesting using this functionality. So it hasn't been > > worth anyone's time to make the necessary changes to the code. > > Imho, we should just state once and for all that the proc connector will > not be namespaced. This is such a corner-case thing and has been > non-namespaced for such a long time without consistent push for it to be > namespaced combined with the fact that this needs quite some code to > make it work correctly that I fear we end up buying more bugs than we're > selling features. And realistically, you and I will end up maintaining > this and I feel this is not worth the time(?). Maybe I'm being too > pessimistic though. > Fair enough. I can certainly look for another way to detect process crashes. Interestingly I found a patch set [2] on the mailing list that attempts to solve the problem I wish to solve, but it doesn't look like the patches were ever developed further. From reading the discussion thread on that patch set it appears that I should be doing some form of polling on the /proc files. Best regards, Matt [1] https://github.com/alliedtelesis/cmsg/blob/master/cmsg/src/service_listener/netlink.c#L61 [2] https://lkml.org/lkml/2018/10/29/638 _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
