// PortForward executes socat in the pod's network namespace and copies
// data between stream (representing the user's local connection on their
// computer) and the specified port in the container.
//
// TODO:
// - match cgroups of container
// - should we support nsenter + socat on the host? (current impl)
// - should we support nsenter + socat in a container, running with elevated privs and --pid=host?
func (dm *DockerManager) PortForward(pod *kubecontainer.Pod, port uint16, stream io.ReadWriteCloser) error {
podInfraContainer := pod.FindContainerByName(PodInfraContainerName)
if podInfraContainer == nil {
return fmt.Errorf("cannot find pod infra container in pod %q", kubecontainer.BuildPodFullName(pod.Name, pod.Namespace))
}
container, err := dm.client.InspectContainer(string(podInfraContainer.ID))
if err != nil {
return err
}
if !container.State.Running {
return fmt.Errorf("container not running (%s)", container)
}
containerPid := container.State.Pid
// TODO what if the host doesn't have it???
_, lookupErr := exec.LookPath("socat")
if lookupErr != nil {
return fmt.Errorf("Unable to do port forwarding: socat not found.")
}
args := []string{"-t", fmt.Sprintf("%d", containerPid), "-n", "socat", "-", fmt.Sprintf("TCP4:localhost:%d", port)}
// TODO use exec.LookPath
command := exec.Command("nsenter", args...)
command.Stdin = stream
command.Stdout = stream
return command.Run()
}
// isPodRunning returns true if all containers of a manifest are running.
func (kl *Kubelet) isPodRunning(pod *api.Pod, runningPod container.Pod) (bool, error) {
for _, container := range pod.Spec.Containers {
c := runningPod.FindContainerByName(container.Name)
if c == nil {
glog.Infof("container %q not found", container.Name)
return false, nil
}
inspectResult, err := kl.dockerClient.InspectContainer(string(c.ID))
if err != nil {
glog.Infof("failed to inspect container %q: %v", container.Name, err)
return false, err
}
if !inspectResult.State.Running {
glog.Infof("container %q not running: %#v", container.Name, inspectResult.State)
return false, nil
}
}
return true, nil
}
// SyncPod syncs the running pod to match the specified desired pod.
func (r *runtime) SyncPod(pod *api.Pod, runningPod kubecontainer.Pod, podStatus api.PodStatus, pullSecrets []api.Secret) error {
podFullName := kubecontainer.GetPodFullName(pod)
if len(runningPod.Containers) == 0 {
glog.V(4).Infof("Pod %q is not running, will start it", podFullName)
return r.RunPod(pod)
}
// Add references to all containers.
unidentifiedContainers := make(map[types.UID]*kubecontainer.Container)
for _, c := range runningPod.Containers {
unidentifiedContainers[c.ID] = c
}
restartPod := false
for _, container := range pod.Spec.Containers {
expectedHash := kubecontainer.HashContainer(&container)
c := runningPod.FindContainerByName(container.Name)
if c == nil {
if kubecontainer.ShouldContainerBeRestarted(&container, pod, &podStatus, r.readinessManager) {
glog.V(3).Infof("Container %+v is dead, but RestartPolicy says that we should restart it.", container)
// TODO(yifan): Containers in one pod are fate-sharing at this moment, see:
// https://github.com/appc/spec/issues/276.
restartPod = true
break
}
continue
}
// TODO(yifan): Take care of host network change.
containerChanged := c.Hash != 0 && c.Hash != expectedHash
if containerChanged {
glog.Infof("Pod %q container %q hash changed (%d vs %d), it will be killed and re-created.", podFullName, container.Name, c.Hash, expectedHash)
restartPod = true
break
}
result, err := r.prober.Probe(pod, podStatus, container, string(c.ID), c.Created)
// TODO(vmarmol): examine this logic.
if err == nil && result != probe.Success {
glog.Infof("Pod %q container %q is unhealthy (probe result: %v), it will be killed and re-created.", podFullName, container.Name, result)
restartPod = true
break
}
if err != nil {
glog.V(2).Infof("Probe container %q failed: %v", container.Name, err)
}
delete(unidentifiedContainers, c.ID)
}
// If there is any unidentified containers, restart the pod.
if len(unidentifiedContainers) > 0 {
restartPod = true
}
if restartPod {
// TODO(yifan): Handle network plugin.
if err := r.KillPod(runningPod); err != nil {
return err
}
if err := r.RunPod(pod); err != nil {
return err
}
}
return nil
}