cri-o/server/sandbox_stop.go
Sebastien Boeuf 1391c5c2fd crio: Ensure container state is stopped when calling StopContainer()
CRI-O works well with runc when stopping a container because as soon
as the container process returns, it can consider every container
resources such as its rootfs as being freed, and it can proceed
further by unmounting it.

But in case of virtualized runtime such as Clear Containers or Kata
Containers, the same rootfs is being mounted into the VM, usually as
a device being hotplugged. This means the runtime will need to be
triggered after the container process has returned. Particularly,
such runtimes should expect a call into "state" in order to realize
the container process is not running anymore, and it would trigger
the container to be officially stopped, proceeding to the necessary
unmounts.

The way this can be done from CRI-O, without impacting the case of
runc, is to explicitly wait for the container status to be updated
into "stopped" after the container process has returned. This way
CRI-O will call into "state" as long as it cannot see the container
status being updated properly, generating an error after a timeout.

Both PollUpdateStatusStopped() and WaitContainerStateStopped() make
use of go routines in order to support a timeout definition. They
follow the waitContainerStop() approach with chControl.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
2018-03-02 14:55:29 -08:00

126 lines
4.1 KiB
Go

package server
import (
"fmt"
"time"
"github.com/containers/storage"
"github.com/docker/docker/pkg/mount"
"github.com/docker/docker/pkg/symlink"
"github.com/kubernetes-incubator/cri-o/lib/sandbox"
"github.com/kubernetes-incubator/cri-o/oci"
"github.com/opencontainers/selinux/go-selinux/label"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"golang.org/x/net/context"
"golang.org/x/sys/unix"
pb "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
)
// StopPodSandbox stops the sandbox. If there are any running containers in the
// sandbox, they should be force terminated.
func (s *Server) StopPodSandbox(ctx context.Context, req *pb.StopPodSandboxRequest) (resp *pb.StopPodSandboxResponse, err error) {
const operation = "stop_pod_sandbox"
defer func() {
recordOperation(operation, time.Now())
recordError(operation, err)
}()
logrus.Debugf("StopPodSandboxRequest %+v", req)
sb, err := s.getPodSandboxFromRequest(req.PodSandboxId)
if err != nil {
if err == sandbox.ErrIDEmpty {
return nil, err
}
// If the sandbox isn't found we just return an empty response to adhere
// the the CRI interface which expects to not error out in not found
// cases.
resp = &pb.StopPodSandboxResponse{}
logrus.Warnf("could not get sandbox %s, it's probably been stopped already: %v", req.PodSandboxId, err)
logrus.Debugf("StopPodSandboxResponse %s: %+v", req.PodSandboxId, resp)
return resp, nil
}
if sb.Stopped() {
resp = &pb.StopPodSandboxResponse{}
logrus.Debugf("StopPodSandboxResponse %s: %+v", sb.ID(), resp)
return resp, nil
}
podInfraContainer := sb.InfraContainer()
containers := sb.Containers().List()
containers = append(containers, podInfraContainer)
for _, c := range containers {
cStatus := s.Runtime().ContainerStatus(c)
if cStatus.Status != oci.ContainerStateStopped {
timeout := int64(10)
if err := s.Runtime().StopContainer(ctx, c, timeout); err != nil {
return nil, fmt.Errorf("failed to stop container %s in pod sandbox %s: %v", c.Name(), sb.ID(), err)
}
if err := s.Runtime().WaitContainerStateStopped(ctx, c, timeout); err != nil {
return nil, fmt.Errorf("failed to get container 'stopped' status %s in pod sandbox %s: %v", c.Name(), sb.ID(), err)
}
if c.ID() == podInfraContainer.ID() {
continue
}
if err := s.StorageRuntimeServer().StopContainer(c.ID()); err != nil && errors.Cause(err) != storage.ErrContainerUnknown {
// assume container already umounted
logrus.Warnf("failed to stop container %s in pod sandbox %s: %v", c.Name(), sb.ID(), err)
}
}
s.ContainerStateToDisk(c)
}
// Clean up sandbox networking and close its network namespace.
hostNetwork := sb.NetNsPath() == ""
s.networkStop(hostNetwork, sb)
if err := sb.NetNsRemove(); err != nil {
return nil, err
}
if err := label.ReleaseLabel(sb.ProcessLabel()); err != nil {
return nil, err
}
// unmount the shm for the pod
if sb.ShmPath() != "/dev/shm" {
// we got namespaces in the form of
// /var/run/containers/storage/overlay-containers/CID/userdata/shm
// but /var/run on most system is symlinked to /run so we first resolve
// the symlink and then try and see if it's mounted
fp, err := symlink.FollowSymlinkInScope(sb.ShmPath(), "/")
if err != nil {
return nil, err
}
if mounted, err := mount.Mounted(fp); err == nil && mounted {
if err := unix.Unmount(fp, unix.MNT_DETACH); err != nil {
return nil, err
}
}
}
if err := s.StorageRuntimeServer().StopContainer(sb.ID()); err != nil && errors.Cause(err) != storage.ErrContainerUnknown {
logrus.Warnf("failed to stop sandbox container in pod sandbox %s: %v", sb.ID(), err)
}
sb.SetStopped()
resp = &pb.StopPodSandboxResponse{}
logrus.Debugf("StopPodSandboxResponse %s: %+v", sb.ID(), resp)
return resp, nil
}
// StopAllPodSandboxes removes all pod sandboxes
func (s *Server) StopAllPodSandboxes() {
logrus.Debugf("StopAllPodSandboxes")
for _, sb := range s.ContainerServer.ListSandboxes() {
pod := &pb.StopPodSandboxRequest{
PodSandboxId: sb.ID(),
}
if _, err := s.StopPodSandbox(nil, pod); err != nil {
logrus.Warnf("could not StopPodSandbox %s: %v", sb.ID(), err)
}
}
}