Currently, if we start a container with:
`docker run -ti --name foo --memory 300M --memory-swap 500M busybox sh`
Then we want to update it with:
`docker update --memory 600M --memory-swap 800M foo`
It'll get error because we can't set memory to 600M with
the 500M limit of swap memory.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Based on Golang document, %s is for "the uninterpreted bytes of the
string or slice", so %v is more appropriate.
Signed-off-by: Peng Gao <peng.gao.dut@gmail.com>
Make sure we don't error out collecting statistics for cases where
pids.max == "max". In that case, we can use a limit of 0 which means
"unlimited".
In addition, change the name of the stats attribute (Max) to mirror the
name of the resources attribute in the spec (Limit) so that it's
consistent internally.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This is required because we manage some of the cgroups ourselves.
This recommendation came from talking with systemd devs about
some of the issues that we see when using the systemd cgroups driver.
Signed-off-by: Mrunal Patel <mrunalp@gmail.com>
In order to allow nice usage statistics (in terms of percentages and
other such data), add the value of pids.max to the PidsStats struct
returned from the pids cgroup controller.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This prior fix to set "-1" explicitly was lost, and it is simpler to use
the same pointer type from the OCI spec to handle nil pointer == -1 ==
unset case.
Also, as a nearly humorous aside, there was a test for MemorySwappiness
that was actually setting Memory, and it was passing because of this
bug (as it was always setting everyone's MemorySwappiness to zero!)
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
If you don't move the process out of the named cgroup for systemd then
systemd will try to delete all the cgroups that the process is currently
in.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
When in a non-initial user namespace you cannot update the devices
cgroup whitelist (or blacklist). The kernel won't allow it. So
detect that case and don't try.
This is a step to being able to run docker/runc containers inside a user
namespaced container.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
It's handled in `destroy()`, no need to do this in
`Apply()`. I found this because systemd cgroup didn't
do this removal and it works well.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
In order to avoid problems with security regressions going unnoticed,
add some unit tests that should make sure security regressions in cgroup
path safety cause tests to fail in runC.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Ensure that path safety is maintained, this essentially reapplies
c0cad6aa5e ("cgroups: fs: fix cgroup.Parent path sanitisation"), which
was accidentally removed in 256f3a8ebc ("Add support for CgroupsPath
field").
Signed-off-by: Aleksa Sarai <asarai@suse.com>
GetMounts is very cpu-expensive. I'll change other funcs in this package
to reuse code from GetCgroupMounts later.
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
Add some further (not critical, since Docker does this already)
validation to systemd slice names, to make sure users don't get cryptic
errors.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Rather than using '/' to denote hierarchy in slice names, systemd uses
'-' in an odd way. This results in runC incorrectly assuming that
certain kernel features are missing (and using inconsistent paths for
the cgroups not supported by systemd), because the "subsystem path" used
is not the one that systemd has created. Fix all of this by properly
expanding slice names.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Modify the memory cgroup code such that kmem is not managed by Set(), in
order to allow updating of memory constraints for containers by Docker.
This also removes the need to make memory a special case cgroup.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
It is vital to loudly fail when a user attempts to set a cgroup limit
(rather than using the system default). Otherwise the user will assume
they have security they do not actually have. This mirrors the original
Apply() (that would set cgroup configs) semantics.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Apply and Set are two separate operations, and it doesn't make sense to
group the two together (especially considering that the bootstrap
process is added to the cgroup as well). The only exception to this is
the memory cgroup, which requires the configuration to be set before
processes can join.
One of the weird cases to deal with is systemd. Systemd sets some of the
cgroup configuration options, but not all of them. Because memory is a
special case, we need to explicitly set memory in the systemd Apply().
Otherwise, the rest can be safely re-applied in .Set() as usual.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Add support for the pids cgroup controller to libcontainer, a recent
feature that is available in Linux 4.3+.
Unfortunately, due to the init process being written in Go, it can spawn
an an unknown number of threads due to blocked syscalls. This results in
the init process being unable to run properly, and thus small pids.max
configs won't work properly.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Mrunal Patel
Qiang Huang
Peng Gao
allencloud
Michael Crosby
Mrunal Patel
Aleksa Sarai
Jessica Frazelle
Alexander Morozov
rajasec
Phil Estes
Serge Hallyn
Aleksa Sarai
Kenfe-Mickael Laventure
Alex Dadgar
Alexander Morozov