Commit cab056226f removed the tryReadonlyMounts
utility, in favor of mounts.ReadOnlyMounts() that was added in commit
daa3a7665e.
That change made part of the comment redundant, because mounts.ReadOnlyMounts
handles both overlayfs read-only mounts (by skipping the workdir mounts), and
sets the "ro" option for other mount-types, but the reason why we're using a
read-only mount is still relevant, so restoring that part of the comment.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
A domainname field was recently added to the OCI spec. Prior to this
folks would need to set this with a sysctl, but now runtimes should be
able to setdomainname(2). There's an open change to runc at the moment
to add support for this so I've just left testing as a couple spec
validations in CRI until that's in and usable.
Signed-off-by: Danny Canter <danny@dcantah.dev>
Go 1.18 and up now provides a strings.Cut() which is better suited for
splitting key/value pairs (and similar constructs), and performs better:
```go
func BenchmarkSplit(b *testing.B) {
b.ReportAllocs()
data := []string{"12hello=world", "12hello=", "12=hello", "12hello"}
for i := 0; i < b.N; i++ {
for _, s := range data {
_ = strings.SplitN(s, "=", 2)[0]
}
}
}
func BenchmarkCut(b *testing.B) {
b.ReportAllocs()
data := []string{"12hello=world", "12hello=", "12=hello", "12hello"}
for i := 0; i < b.N; i++ {
for _, s := range data {
_, _, _ = strings.Cut(s, "=")
}
}
}
```
BenchmarkSplit
BenchmarkSplit-10 8244206 128.0 ns/op 128 B/op 4 allocs/op
BenchmarkCut
BenchmarkCut-10 54411998 21.80 ns/op 0 B/op 0 allocs/op
While looking at occurrences of `strings.Split()`, I also updated some for alternatives,
or added some constraints; for cases where an specific number of items is expected, I used `strings.SplitN()`
with a suitable limit. This prevents (theoretical) unlimited splits.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This change modifies WithLinuxDevice to take an option `followSymlink`
and be unexported as `withLinuxDevice`. An option
`WithLinuxDeviceFollowSymlinks` will call this unexported option to
follow a symlink, which will resolve a symlink before calling
`DeviceFromPath`. `WithLinuxDevice` has been changed to call
`withLinuxDevice` without following symlinks.
Signed-off-by: Gavin Inglis <giinglis@amazon.com>
Remove nolint-comments that weren't hit by linters, and remove the "structcheck"
and "varcheck" linters, as they have been deprecated:
WARN [runner] The linter 'structcheck' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter. Replaced by unused.
WARN [runner] The linter 'varcheck' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter. Replaced by unused.
WARN [linters context] structcheck is disabled because of generics. You can track the evolution of the generics support by following the https://github.com/golangci/golangci-lint/issues/2649.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
- fix "nolint" comments to be in the correct format (`//nolint:<linters>[,<linter>`
no leading space, required colon (`:`) and linters.
- remove "nolint" comments for errcheck, which is disabled in our config.
- remove "nolint" comments that were no longer needed (nolintlint).
- where known, add a comment describing why a "nolint" was applied.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
ArgsEscaped has now been merged into upstream OCI image spec.
This change removes the workaround we were doing in containerd
to deserialize the extra json outside of the spec and instead
just uses the formal spec types.
Signed-off-by: Justin Terry <jlterry@amazon.com>
This allows running Linux containers on FreeBSD and modifies the
mounts so that they represent the linux emulated filesystems, as per:
https://wiki.freebsd.org/LinuxJails
Co-authored-by: Gijs Peskens <gijs@peskens.net>, Samuel Karp <samuelkarp@users.noreply.github.com>
Signed-off-by: Artem Khramov <akhramov@pm.me>
A container should not have access to tun/tap device, unless it is explicitly
specified in configuration.
This device was already removed from docker's default, and runc's default;
- 2ce40b6ad7
- 9c4570a958
Per the commit message in runc, this should also fix these messages;
> Apr 26 03:46:56 foo.bar systemd[1]: Couldn't stat device /dev/char/10:200: No such file or directory
coming from systemd on every container start, when the systemd cgroup driver
is used, and the system runs an old (< v240) version of systemd
(the message was presumably eliminated by [1]).
[1]: d5aecba6e0
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
There's two mappings of hostpath to IDType and ID in the wild:
- dockershim and dockerd-cri (implicitly via docker) use class/ID
-- The only supported IDType in Docker is 'class'.
-- https://github.com/aarnaud/k8s-directx-device-plugin generates this form
- https://github.com/jterry75/cri (windows_port branch) uses IDType://ID
-- hcsshim's CRI test suite generates this form
`://` is much more easily distinguishable, so I've gone with that one as
the generic separator, with `class/` as a special-case.
Signed-off-by: Paul "TBBle" Hampson <Paul.Hampson@Pobox.com>
Adds support for Windows container images built by Docker
that contain the ArgsEscaped boolean in the ImageConfig. This
is a non-OCI entry that tells the runtime that the Entrypoint
and/or Cmd are a single element array with the args pre-escaped
into a single CommandLine that should be passed directly to
Windows rather than passed as an args array which will be
additionally escaped.
Signed-off-by: Justin Terry <jlterry@amazon.com>
The Linux kernel never sets the Inheritable capability flag to
anything other than empty. Non-empty values are always exclusively
set by userspace code.
[The kernel stopped defaulting this set of capability values to the
full set in 2000 after a privilege escalation with Capabilities
affecting Sendmail and others.]
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
In linux kernel, the umount writable-mountpoint will try to do sync-fs
to make sure that the dirty pages to the underlying filesystems. The many
number of umount actions in the same time maybe introduce performance
issue in IOPS limited disk.
When CRI-plugin creates container, it will temp-mount rootfs to read
that UID/GID info for entrypoint. Basically, the rootfs is writable
snapshotter and then after read, umount will invoke sync-fs action.
For example, using overlayfs on ext4 and use bcc-tools to monitor
ext4_sync_fs call.
```
// uname -a
Linux chaofan 5.13.0-27-generic #29~20.04.1-Ubuntu SMP Fri Jan 14 00:32:30 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
// open terminal 1
kubectl run --image=nginx --image-pull-policy=IfNotPresent nginx-pod
// open terminal 2
/usr/share/bcc/tools/stackcount ext4_sync_fs -i 1 -v -P
ext4_sync_fs
sync_filesystem
ovl_sync_fs
__sync_filesystem
sync_filesystem
generic_shutdown_super
kill_anon_super
deactivate_locked_super
deactivate_super
cleanup_mnt
__cleanup_mnt
task_work_run
exit_to_user_mode_prepare
syscall_exit_to_user_mode
do_syscall_64
entry_SYSCALL_64_after_hwframe
syscall.Syscall.abi0
github.com/containerd/containerd/mount.unmount
github.com/containerd/containerd/mount.UnmountAll
github.com/containerd/containerd/mount.WithTempMount.func2
github.com/containerd/containerd/mount.WithTempMount
github.com/containerd/containerd/oci.WithUserID.func1
github.com/containerd/containerd/oci.WithUser.func1
github.com/containerd/containerd/oci.ApplyOpts
github.com/containerd/containerd.WithSpec.func1
github.com/containerd/containerd.(*Client).NewContainer
github.com/containerd/containerd/pkg/cri/server.(*criService).CreateContainer
github.com/containerd/containerd/pkg/cri/server.(*instrumentedService).CreateContainer
k8s.io/cri-api/pkg/apis/runtime/v1._RuntimeService_CreateContainer_Handler.func1
github.com/containerd/containerd/services/server.unaryNamespaceInterceptor
github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryServer.func1.1.1
github.com/grpc-ecosystem/go-grpc-prometheus.(*ServerMetrics).UnaryServerInterceptor.func1
github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryServer.func1.1.1
go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.UnaryServerInterceptor.func1
github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryServer.func1.1.1
github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryServer.func1
k8s.io/cri-api/pkg/apis/runtime/v1._RuntimeService_CreateContainer_Handler
google.golang.org/grpc.(*Server).processUnaryRPC
google.golang.org/grpc.(*Server).handleStream
google.golang.org/grpc.(*Server).serveStreams.func1.2
runtime.goexit.abi0
containerd [34771]
1
```
If there are comming several create requestes, umount actions might
bring high IO pressure on the /var/lib/containerd's underlying disk.
After checkout the kernel code[1], the kernel will not call
__sync_filesystem if the mount is readonly. Based on this, containerd
should use readonly mount to get UID/GID information.
Reference:
* [1] https://elixir.bootlin.com/linux/v5.13/source/fs/sync.c#L61Closes: #4604
Signed-off-by: Wei Fu <fuweid89@gmail.com>
This will help to reduce the amount of runc/libcontainer code that's used in
Moby / Docker Engine (in favor of using the containerd implementation).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
The `oci.WithUser` function relies on checking a path on the hosts disk to
grab/validate the uid:gid pair for the user string provided. For LCOW it's a
bit harder to confirm that the user actually exists on the host as a rootfs isn't
mounted on the host and shared into the guest, but rather the rootfs is constructed
entirely in the guest itself. To accomodate this, a spot to place the user string
provided by a client as-is is needed.
The `Username` field on the runtime spec is marked by Platform as only for Windows,
and in this case it *is* being set on a Windows host at least, but will be used as a
temporary holding spot until the guest can use the string to perform these same
operations to grab the uid:gid inside.
Signed-off-by: Daniel Canter <dcanter@microsoft.com>
Move `pkg/cri/opts.WithoutRunMount` function to `oci.WithoutRunMount`
so that it can be used without dependency on CRI.
Also add `oci.WithoutMounts(dests ...string)` for generality.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
This enables cases where devices exist in a subdirectory of /dev,
particularly where those device names are not portable across machines,
which makes it problematic to specify from a runtime such as cri.
Added this to `ctr` as well so I could test that the code at least
works.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This change is needed for running the latest containerd inside Docker
that is not aware of the recently added caps (BPF, PERFMON, CHECKPOINT_RESTORE).
Without this change, containerd inside Docker fails to run containers with
"apply caps: operation not permitted" error.
See kubernetes-sigs/kind 2058
NOTE: The caller process of this function is now assumed to be as
privileged as possible.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
The Err() method should be called after the Scan() loop, not inside it.
Found by: git grep -A3 -F '.Scan()'
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
