2009/8/24 Daniel Lezcano <span dir="ltr"><<a href="mailto:daniel.lezcano@free.fr">daniel.lezcano@free.fr</a>></span><br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div><div></div><div class="h5">Krzysztof Taraszka wrote:<br>
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2009/8/24 Daniel Lezcano <<a href="mailto:dlezcano@fr.ibm.com" target="_blank">dlezcano@fr.ibm.com</a>><br>
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Krzysztof Taraszka wrote:<br>
<br>
<br>
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2009/8/24 Daniel Lezcano <<a href="mailto:daniel.lezcano@free.fr" target="_blank">daniel.lezcano@free.fr</a>><br>
<br>
Krzysztof Taraszka wrote:<br>
<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
2009/8/23 Daniel Lezcano <<a href="mailto:daniel.lezcano@free.fr" target="_blank">daniel.lezcano@free.fr</a>><br>
<br>
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(...)<br>
<br>
<br>
<br>
<br>
With the lxc tools I did:<br>
<br>
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lxc-execute -n foo /bin/bash<br>
echo 268435456 > /cgroup/foo/memory.limit_in_bytes<br>
mount --bind /cgroup/foo/memory.meminfo /proc/meminfo<br>
for i in $(seq 1 100); do sleep 3600 & done<br>
<br>
<br>
<br>
<br>
</blockquote>
(...)<br>
<br>
<br>
<br>
<br>
:)<br>
<br>
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hmmm... I think that access to the cgroup inside container is very<br>
<br>
</blockquote>
risk<br>
because I am able to manage for example memory resources (what if I am<br>
not<br>
the host owner and... I can give me via non-secure mounted /cgroup<br>
(inside<br>
container) all available memory resources...).<br>
I think that the /proc/meminfo should be pass to the container in the<br>
other<br>
way, but this is the topic for the other thread.<br>
<br>
<br>
It is not a problem, I did it in this way because it's easy to test but<br>
<br>
</blockquote>
in<br>
a real use case, the memory limit is setup by the lxc configuration file<br>
and<br>
the cgroup directory will be no longer accessible from the container.<br>
<br>
<br>
<br>
</blockquote>
So.. how there will be another method (more secure) for giving<br>
/proc/meminfo<br>
with limits to the container, right?<br>
<br>
<br>
</blockquote>
Same method. The lxc tools can be configured with a fstab to mount more<br>
mount points, furthermore if memory.meminfo is available I will add the code<br>
to mount it automatically to /proc/meminfo in the lxc tools.<br>
<br>
<br>
</blockquote>
<br>
<br>
Hmm... setup_fs() from lxc_init.c or another way?<br>
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</blockquote></div></div>
No, I was thinking in the setup_cgroup() function in conf.c.<br>
<br>
Something like:<br>
<br>
...<br>
<br>
if (!access("/var/lib/lxc/mycontainer/nsgroup/memory.meminfo"), F_OK) {<br>
mount("/var/lib/lxc/mycontainer/nsgroup/memory.meminfo", "/proc/meminfo", MS_BIND, ...);<br>
}<br>
<br>
...<br>
<br>
<br>
but a bit more clean :)<br>
</blockquote></div><br><br>hmm... ok, got it, but don't know why does it won't work ;)<br><br>@@ -999,12 +999,14 @@<br> static int setup_cgroup(const char *name)<br> {<br> char filename[MAXPATHLEN];<br>+ char meminfofilename[MAXPATHLEN];<br>
char line[MAXPATHLEN];<br> struct stat s;<br> int ret;<br> <br> snprintf(filename, MAXPATHLEN, LXCPATH "/%s/cgroup", name);<br>-<br>+ snprintf(meminfofilename, MAXPATHLEN, LXCPATH "/%s/nsgroup/memory.meminfo", name);<br>
+ <br> if (stat(filename, &s)) {<br> SYSERROR("failed to stat '%s'", filename);<br> return -1;<br>@@ -1024,6 +1026,10 @@<br> <br> INFO("cgroup has been setup");<br>
<br>+ /* mount memory.meminfo as /proc/meminfo */<br>+ if (!access(meminfofilename, F_OK)) {<br>+ mount(meminfofilename, "/proc/meminfo", "none", MS_BIND, 0);<br>+ }<br> return 0;<br>
}<br><br><br>hmm... any idea Daniel? :)<br><br>-- <br>Krzysztof Taraszka<br>