Serge E. Hallyn wrote: > Quoting Daniel Lezcano (daniel.lezcano@xxxxxxx): > >> Serge E. Hallyn wrote: >> >>> Quoting Daniel Lezcano (daniel.lezcano@xxxxxxx): >>> >>> >>>> Krzysztof Taraszka wrote: >>>> >>>> >>>>> Okey. >>>>> I made few tests and this two ways work: >>>>> >>>>> First way: >>>>> ======= >>>>> lxc. smack enabled, policy loaded. cgroup not labeled. >>>>> >>>>> a) start container >>>>> b) mount cgroup inside container >>>>> c) mount --bind /cgroup/foo/memory.meminfo /proc/meminfo >>>>> d) secure the /cgroup on the host (ie: attr -S -s SMACK64 -V host /cgroup). >>>>> >>>>> this step can be done inside lxc tools ;) >>>>> >>>>> Second way: >>>>> ========== >>>>> lxc. smack enabled, policy loaded. cgroup not labeled. >>>>> >>>>> a) do not label whole /cgrop directory (DO NOT DO: attr -S -s SMACK64 -V >>>>> host /cgroup). Label dedicate files only (for example: /cgroup/cpuset.cpus, >>>>> /cgroup/vs1/cpuset.cpus, etc). Do not label the /cgrop/vs1 directory. Label >>>>> with vs1 label only /cgroup/vs1/memory.meminfo. All other files label with >>>>> host label to do not allow read them. >>>>> b) start container >>>>> c) mount cgroup inside container >>>>> d) mount --bind /cgroup/foo/memory.meminfo /proc/meminfo >>>>> >>>>> steps: b, c, d can be done inside lxc tools. step a can't and it is base on >>>>> the admin policy. >>>>> >>>>> I think that the first solution is more automatic and can be done by lxc >>>>> tools (maybe command line switch? I can prepare a patch for that. >>>>> >>>>> >>>> I do not know smack, what does smack here ? Will this solution avoid >>>> the container to overwrite /proc/meminfo by remounting /proc ? >>>> >>>> >>> Right, in the first way he is labeling the whole cgroupfs with a label >>> which prevents the container from mounting it. In the second way, >>> the specific files are labeled. >>> >>> >> Ah, got it ! :) >> >> The idea of Kamezawa-san to use a fuse proc is maybe a good idea in this >> case. So we can address the entire /proc specific informations. For >> > > I agree, nice idea. And hopefully pretty simple to whip up for the > meminfo and cpuinfo files as an example. > > Are you thinking a fuse fs which takes a config file, holds an open > ref to its ancestor /proc, and for each file looks in a config file to > decide whether to show userspace: > 1. nothing > 2. the underlying file, unprocessed > 3. a simple ascii file instead > 4. the underlying file, processed? > Yes, exactly :) But, I am not sure how to retrieve the container context, I mean how to pick and return the right information. eg: in the container foo, when looking at /proc/meminfo, fuse-lxcfs should process /cgroup/foo/(somefiles), how to know the request is coming from 'foo' without doing multiple mount, one in each container ? >> example, like the /proc/meminfo, there is the /proc/cpuinfo. If you >> restrict the usage to a subset of your cpus with cpuset and you look at >> /proc/cpuinfo, you see all the cpus; it is not a big problem until a >> computation application looks at this file and choose to fork(n cpus) >> and set the affinity of each process to each cpu ... AFAIR, this is the >> case for HPC applications. >> _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
