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>
Add a unit test to check that bind mounts that have a part of its
path non accessible by others still work when using user namespaces.
To do this, we also modify newRoot() to return rootfs directories that
can be traverse by others, so the rootfs created works for all test
(either running in a userns or not).
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io>
Co-authored-by: Rodrigo Campos <rodrigo@kinvolk.io>
Go 1.15 is not supported since Go 1.17 release (16 Aug 2021), and some
packages that we use already require Go 1.16+ (notably,
github.com/cilium/ebpf v0.7.0).
Let's require Go 1.16+.
Remove Go version requirement from README when describing dependencies,
since it is no longer needed:
$ GO=go1.15.15 make vendor
go1.15.15 mod tidy
go mod tidy: go.mod file indicates go 1.16, but maximum supported version is 1.15
make: *** [Makefile:141: vendor] Error 1
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Jobs verify/compile-buildtags and verify/deps relied on whatever Go
version is available from the Ubuntu-20.04 image, which seems to be
1.15.x).
Job test/cross-i386 was installing whatever Go version is considered to
be the default one by actions/setup-go@v2, which seems to be go 1.15.15
at the moment.
Fix all three jobs to install Go 1.x (which should translate to latest
stable Go version, i.e. 1.17.2 as of now).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The previous commit fixed an issue opening bind mount sources. This
commit just adds integration tests to make sure we don't regress on this
in the future.
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io>
Co-authored-by: Rodrigo Campos <rodrigo@kinvolk.io>
The source of the bind mount might not be accessible in a different user
namespace because a component of the source path might not be traversed
under the users and groups mapped inside the user namespace. This caused
errors such as the following:
# time="2020-06-22T13:48:26Z" level=error msg="container_linux.go:367:
starting container process caused: process_linux.go:459:
container init caused: rootfs_linux.go:58:
mounting \"/tmp/busyboxtest/source-inaccessible/dir\"
to rootfs at \"/tmp/inaccessible\" caused:
stat /tmp/busyboxtest/source-inaccessible/dir: permission denied"
To solve this problem, this patch performs the following:
1. in nsexec.c, it opens the source path in the host userns (so we have
the right permissions to open it) but in the container mntns (so the
kernel cross mntns mount check let us mount it later:
https://github.com/torvalds/linux/blob/v5.8/fs/namespace.c#L2312).
2. in nsexec.c, it passes the file descriptors of the source to the
child process with SCM_RIGHTS.
3. In runc-init in Golang, it finishes the mounts while inside the
userns even without access to the some components of the source
paths.
Passing the fds with SCM_RIGHTS is necessary because once the child
process is in the container mntns, it is already in the container userns
so it cannot temporarily join the host mntns.
This patch uses the existing mechanism with _LIBCONTAINER_* environment
variables to pass the file descriptors from runc to runc init.
This patch uses the existing mechanism with the Netlink-style bootstrap
to pass information about the list of source mounts to nsexec.c.
Rootless containers don't use this bind mount sources fdpassing
mechanism because we can't setns() to the target mntns in a rootless
container (we don't have the privileges when we are in the host userns).
This patch takes care of using O_CLOEXEC on mount fds, and close them
early.
Fixes: #2484.
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io>
Co-authored-by: Rodrigo Campos <rodrigo@kinvolk.io>
Export getIntelRdtRoot function as Root.
This is needed by google/cadvisor, which is (ab)using GetIntelRdtPath,
removed by commit 7296dc1712.
While at it, do some minimal refactoring to always use Root()
internally, not relying on variable value. Other than that it's just
some renaming.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
If the container binary to be run is removed in between runc create
and runc start, the latter spits the following error:
> can't exec user process: no such file or directory
This is a bit confusing since we don't see what file is missing.
Wrap the unix.Exec error into os.PathError, like in many other cases,
to provide some context. Remove the error wrapping from
(*linuxStandardInit).Init as it is now redundant.
With this patch, the error is now:
> exec /bin/false: no such file or directory
Reported-by: Daniel J Walsh <dwalsh@redhat.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin