cri-o/server/sandbox.go
Samuel Ortiz 4cab8ed06a
sandbox: Use persistent networking namespace
Because they need to prepare the hypervisor networking interfaces
and have them match the ones created in the pod networking
namespace (typically to bridge TAP and veth interfaces), hypervisor
based container runtimes need the sandbox pod networking namespace
to be set up before it's created. They can then prepare and start
the hypervisor interfaces when creating the pod virtual machine.

In order to do so, we need to create per pod persitent networking
namespaces that we pass to the CNI plugin. This patch leverages
the CNI ns package to create such namespaces under /var/run/netns,
and assign them to all pod containers.
The persitent namespace is removed when either the pod is stopped
or removed.

Since the StopPodSandbox() API can be called multiple times from
kubelet, we track the pod networking namespace state (closed or
not) so that we don't get a containernetworking/ns package error
when calling its Close() routine multiple times as well.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2016-12-12 19:48:23 +01:00

175 lines
3.3 KiB
Go

package server
import (
"errors"
"fmt"
"sync"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/stringid"
"github.com/kubernetes-incubator/cri-o/oci"
"github.com/containernetworking/cni/pkg/ns"
"k8s.io/kubernetes/pkg/fields"
pb "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
)
type sandboxNetNs struct {
sync.Mutex
ns ns.NetNS
closed bool
}
func netNsGet(nspath string) (*sandboxNetNs, error) {
if err := ns.IsNSorErr(nspath); err != nil {
return nil, errSandboxClosedNetNS
}
netNS, err := ns.GetNS(nspath)
if err != nil {
return nil, err
}
return &sandboxNetNs{ns: netNS, closed: false,}, nil
}
func hostNetNsPath() (string, error) {
netNS, err := ns.GetCurrentNS()
if err != nil {
return "", err
}
defer netNS.Close()
return netNS.Path(), nil
}
type sandbox struct {
id string
name string
logDir string
labels fields.Set
annotations map[string]string
infraContainer *oci.Container
containers oci.Store
processLabel string
mountLabel string
netns *sandboxNetNs
metadata *pb.PodSandboxMetadata
shmPath string
}
const (
podDefaultNamespace = "default"
defaultShmSize = 64 * 1024 * 1024
)
var (
errSandboxIDEmpty = errors.New("PodSandboxId should not be empty")
errSandboxClosedNetNS = errors.New("PodSandbox networking namespace is closed")
)
func (s *sandbox) addContainer(c *oci.Container) {
s.containers.Add(c.Name(), c)
}
func (s *sandbox) getContainer(name string) *oci.Container {
return s.containers.Get(name)
}
func (s *sandbox) removeContainer(c *oci.Container) {
s.containers.Delete(c.Name())
}
func (s *sandbox) netNs() ns.NetNS {
if s.netns == nil {
return nil
}
return s.netns.ns
}
func (s *sandbox) netNsPath() string {
if s.netns == nil {
return ""
}
return s.netns.ns.Path()
}
func (s *sandbox) netNsCreate() error {
if s.netns != nil {
return fmt.Errorf("net NS already created")
}
netNS, err := ns.NewNS()
if err != nil {
return err
}
s.netns = &sandboxNetNs{
ns: netNS,
closed: false,
}
return nil
}
func (s *sandbox) netNsRemove() error {
if s.netns == nil {
logrus.Warn("no networking namespace")
return nil
}
s.netns.Lock()
defer s.netns.Unlock()
if s.netns.closed {
// netNsRemove() can be called multiple
// times without returning an error.
return nil
}
if err := s.netns.ns.Close(); err != nil {
return err
}
s.netns.closed = true
return nil
}
func (s *Server) generatePodIDandName(name string, namespace string, attempt uint32) (string, string, error) {
var (
err error
id = stringid.GenerateNonCryptoID()
)
if namespace == "" {
namespace = podDefaultNamespace
}
if name, err = s.reservePodName(id, fmt.Sprintf("%s-%s-%v", namespace, name, attempt)); err != nil {
return "", "", err
}
return id, name, err
}
type podSandboxRequest interface {
GetPodSandboxId() string
}
func (s *Server) getPodSandboxFromRequest(req podSandboxRequest) (*sandbox, error) {
sbID := req.GetPodSandboxId()
if sbID == "" {
return nil, errSandboxIDEmpty
}
sandboxID, err := s.podIDIndex.Get(sbID)
if err != nil {
return nil, fmt.Errorf("PodSandbox with ID starting with %s not found: %v", sbID, err)
}
sb := s.getSandbox(sandboxID)
if sb == nil {
return nil, fmt.Errorf("specified sandbox not found: %s", sandboxID)
}
return sb, nil
}