Quoting Jean-Marc Pigeon (jmp@xxxxxxx): > Hello, > > > > > > I was wondering out loud about the best design to solve his problem. > > > > If we try to redirect kernel-generated messages to containers, we have > > several problems, including whether we need to duplicate the messages > > to the host container. So in one sense it seems more flexible to > > 1. send everything to host syslog > No, if we do that all CONTs message will reach > the same bucket and it will be difficult to sort > them out.. > CONT sys_admin and HOST sys_admin could be different > "entity", so you debug CONT config and critical > needed information reach HOST (which you do not > have access to). Yes, so a privileged task on HOST must pass that information back to you on CONT. That is not a valid complaint imo. But how to sort the msgs out is a valid question. We need some sort of identifier, unique system-wide, attached to.. something. Is ifindex unique system-wide right now? Oh, IIRC it is, but we wnat it to be containerized, so that would be a bad choice :) > > 2. clamp down on syslog use by processes not in the init_user_ns > Could give me more detail??... Simplest choices would be to just refuse sys_syslog() and open(/proc/kmsg) altogether from a container, or to only allow reading/writing messages to own syslog. (I had hoped to find time to try out the second option but simply haven't had the time, and it doesn't look like I will very soon. So if anyone else wants to, pls jump at it...) Then /proc/kmsg can provide what I described above through a FUSE file, and if, as you mentioned, the container unmounts the FUSE fs and gets to real procfs, they just get nothing. > > 3. let the userspace on the host copy messages into a socket or > > file so child container can pretend it has real syslog. > > So you trap printk message from CONT on the HOST and > redirect them on CONT but on a standard syslog channel. > Seem OK to me, as long /proc/kmsg is not existing > (/dev/null) in the CONT file tree. > > -- > A bientôt > ========================================================================== > Jean-Marc Pigeon Internet: jmp@xxxxxxx > SAFE Inc. Phone: (514) 493-4280 > Fax: (514) 493-1946 > Clement, 'a kiss solution' to get rid of SPAM (at last) > Clement' Home base <"http://www.clement.safe.ca";> > ========================================================================== _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
