I have noticed that libct/cg/fs allocates 8K during init on every runc
execution:
> init github.com/opencontainers/runc/libcontainer/cgroups/fs @1.5 ms, 0.028 ms clock, 8512 bytes, 13 allocs
Apparently this is caused by global HugePageSizes variable init, which
is only used from GetStats (i.e. it is never used by runc itself).
Remove it, and use HugePageSizes() directly instead. Make it init-once,
so that GetStats (which, I guess, is periodically called by kubernetes)
does not re-read huge page sizes over and over.
This also removes 12 allocs and 8K from libct/cg/fs init section:
> $ time GODEBUG=inittrace=1 ./runc --help 2>&1 | grep cgroups/fs
> init github.com/opencontainers/runc/libcontainer/cgroups/fs @1.5 ms, 0.003 ms clock, 16 bytes, 1 allocs
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Since GetHugePageSize do not have any external users (checked by
sourcegraph), and no internal user ever uses its second return value
(the error), let's drop it.
2. Rename GetHugePageSize -> HugePageSizes (drop the Get prefix as per
Go guidelines, add suffix since we return many sizes).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The staticcheck linter points out that the err != nil comparison
after system.Exec is always true:
> libcontainer/standard_init_linux.go#L253
> SA4023: this comparison is always true (staticcheck)
> libcontainer/system/linux.go#L43
> SA4023(related information): github.com/opencontainers/runc/libcontainer/system.Exec never returns a nil interface value (staticcheck)
Indeed, Exec either returns an error or does not return at all.
Remove the (useless) check.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Decapitalize errors.
2. Rename isValidName to checkPropertyName.
3. Make it return a specific error.
Suggested-by: Sebastiaan van Stijn <github@gone.nl>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Also, add a simple test and a benchmark (just out of sheer curiosity).
Benchmark results:
name old time/op new time/op delta
IsValidName-4 540ns ± 3% 45ns ± 1% -91.76% (p=0.008 n=5+5)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit 1cd71dfd7 added isSecSuffix, but the same thing can be done
easily without a regex. This is faster and saves some init time and
memory.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
parseMountOption already returns way too many values, making the code
kind of hard to read.
Since all of the return values are used as is to populate the fields of
configs.Mount, let's change it to return (semi-)populated *configs.Mount
instead.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This makes the repeated calls to parseMountOptions faster,
and decreases the amount of garbage to collect.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
These two maps are the same, except that mountPropagationMapping
has an extra element with key of "" and value of 0. Since the
code already checks for f != 0, this extra element is not a problem.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Eliminate some of these allocations when starting runc:
> init github.com/opencontainers/runc/libcontainer/specconv @10 ms, 0.11 ms clock, 5408 bytes, 70 allocs
Most of this (4K) is the two regexes, which are left intact for now.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
When I tried to start a rootless container under a different/wrong user,
I got:
$ ../runc/runc --systemd-cgroup --root /tmp/runc.$$ run 445
ERRO[0000] runc run failed: operation not permitted
This is obviously not good enough. With this commit, the error is:
ERRO[0000] runc run failed: fchown fd 9: operation not permitted
Alas, there are still some code that returns unwrapped errnos from
various unix calls.
This is a followup to commit d8ba4128b2 which wrapped many, but not
all, bare unix errors. Do wrap some more, using either os.PathError or
os.SyscallError.
While at it,
- use os.SyscallError instead of os.NewSyscallError;
- use errors.Is(err, os.ErrXxx) instead of os.IsXxx(err).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
A bug in systemd-249.6-2.fc35.x86_64 prevents rootless containers from
start when systemd manager is used.
Apparently, "config exclude" is not working in F35 dnf shell either, so
use a workaround of specifying --exclude from the command line.
This should fix runc CI for the time being.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Sometimes a container cgroup already exists but is frozen.
When this happens, runc init hangs, and it's not clear what is going on.
Refuse to run in a frozen cgroup; add a test case.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Currently runc allows multiple containers to share the same cgroup (for
example, by having the same cgroupPath in config.json). While such
shared configuration might be OK, there are some issues:
- When each container has its own resource limits, the order of
containers start determines whose limits will be effectively applied.
- When one of containers is paused, all others are paused, too.
- When a container is paused, any attempt to do runc create/run/exec
end up with runc init stuck inside a frozen cgroup.
- When a systemd cgroup manager is used, this becomes even worse -- such
as, stop (or even failed start) of any container results in
"stopTransientUnit" command being sent to systemd, and so (depending on
unit properties) other containers can receive SIGTERM, be killed after a
timeout etc.
Any of the above may lead to various hard-to-debug situations in production
(runc init stuck, cgroup removal error, wrong resource limits, init not
reaping zombies etc.).
One obvious solution is to refuse a non-empty cgroup when starting a new
container. This would be a breaking change though, so let's make it in
steps, with the first step is issue a warning and a deprecated notice
about a non-empty cgroup.
Later (in runc 1.2) we will replace this warning with an error.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Currently, if a container is paused (i.e. its cgroup is frozen), runc exec
just hangs, and it is not obvious why.
Refuse to exec in a paused container. Add a test case.
In case runc exec in a paused container is a legit use case,
add --ignore-paused option to override the check. Document it,
add a test case.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Also rename `Vagrantfile.fedora%d` to `Vagrantfile.fedora` so that
we do not need to reset the commit log on upgrading the Fedora release.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Some test directories are created using mktemp -d, and so they have
permissions set to 0700 and are thus inaccessible to a user inside
userns. This was workarounded for $ROOT in userns.bats before.
Now, when we have updated Cirrus CI config to use Fedora 35 (rather than
34), userns tests fail:
> runc run failed: unable to start container process: error during
> container init: error preparing rootfs: mount
> /tmp/bats-run-4pCERd/runc.f66gCC/bundle/rootfs:/tmp/bats-run-4pCERd/runc.f66gCC/bundle/rootfs,
> flags: 0x5000: permission denied
Fedora 34 image used kernel v5.11, while Fedora 35 has v5.15.
Apparently, the newer kernel also checks that the parent directories
are accessible by the user before doing mount.
Move the old workaround from userns.bats to helpers.bats, drop the r bit
(not needed), and add $BATS_RUN_TMPDIR (also created by mktemp -d) to
fix userns.bats test failures under Fedora 35.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The misc cgroup controller, introduced in Linux 5.13, is still unknown
to systemd, and thus it cannot delegate it. Add an appropriate fixup
to the test case, similar to an earlier commit 601cf5825f.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Runtime spec says:
> sysctl (object, OPTIONAL) allows kernel parameters to be modified at
> runtime for the container. For more information, see the sysctl(8)
> man page.
and sysctl(8) says:
> variable
> The name of a key to read from. An example is
> kernel.ostype. The '/' separator is also accepted in place of a '.'.
Apparently, runc config validator do not support sysctls with / as a
separator. Fortunately this is a one-line fix.
Add some more test data where / is used as a separator.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin