kubernetes/pkg/kubelet/network/hairpin/hairpin.go
Kubernetes Submit Queue 4515f72824 Merge pull request #38101 from CaoShuFeng/haripin_nsenter
Automatic merge from submit-queue (batch tested with PRs 38101, 41431, 39606, 41569, 41509)

[hairpin] fix argument of nsenter

**Release note**:

```release-note
None
```

We should use:
	nsenter --net=netnsPath -- -F some_command
instend of:
	nsenter -n netnsPath -- -F some_command
Because "nsenter -n netnsPath" get an error output:
	# nsenter -n /proc/67197/ns/net ip addr
	nsenter: neither filename nor target pid supplied for ns/net

If we really want use -n, we need to use -n in such format:
	# sudo nsenter -n/proc/67197/ns/net ip addr
2017-02-16 15:49:10 -08:00

111 lines
3.5 KiB
Go

/*
Copyright 2015 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package hairpin
import (
"fmt"
"io/ioutil"
"net"
"os"
"path"
"regexp"
"strconv"
"github.com/golang/glog"
"k8s.io/kubernetes/pkg/util/exec"
)
const (
sysfsNetPath = "/sys/devices/virtual/net"
brportRelativePath = "brport"
hairpinModeRelativePath = "hairpin_mode"
hairpinEnable = "1"
)
var (
ethtoolOutputRegex = regexp.MustCompile("peer_ifindex: (\\d+)")
)
func SetUpContainerPid(containerPid int, containerInterfaceName string) error {
pidStr := fmt.Sprintf("%d", containerPid)
nsenterArgs := []string{"-t", pidStr, "-n"}
return setUpContainerInternal(containerInterfaceName, pidStr, nsenterArgs)
}
func SetUpContainerPath(netnsPath string, containerInterfaceName string) error {
if netnsPath[0] != '/' {
return fmt.Errorf("netnsPath path '%s' was invalid", netnsPath)
}
nsenterArgs := []string{"--net=" + netnsPath}
return setUpContainerInternal(containerInterfaceName, netnsPath, nsenterArgs)
}
func setUpContainerInternal(containerInterfaceName, containerDesc string, nsenterArgs []string) error {
e := exec.New()
hostIfName, err := findPairInterfaceOfContainerInterface(e, containerInterfaceName, containerDesc, nsenterArgs)
if err != nil {
return err
}
return setUpInterface(hostIfName)
}
func findPairInterfaceOfContainerInterface(e exec.Interface, containerInterfaceName, containerDesc string, nsenterArgs []string) (string, error) {
nsenterPath, err := e.LookPath("nsenter")
if err != nil {
return "", err
}
ethtoolPath, err := e.LookPath("ethtool")
if err != nil {
return "", err
}
nsenterArgs = append(nsenterArgs, "-F", "--", ethtoolPath, "--statistics", containerInterfaceName)
output, err := e.Command(nsenterPath, nsenterArgs...).CombinedOutput()
if err != nil {
return "", fmt.Errorf("Unable to query interface %s of container %s: %v: %s", containerInterfaceName, containerDesc, err, string(output))
}
// look for peer_ifindex
match := ethtoolOutputRegex.FindSubmatch(output)
if match == nil {
return "", fmt.Errorf("No peer_ifindex in interface statistics for %s of container %s", containerInterfaceName, containerDesc)
}
peerIfIndex, err := strconv.Atoi(string(match[1]))
if err != nil { // seems impossible (\d+ not numeric)
return "", fmt.Errorf("peer_ifindex wasn't numeric: %s: %v", match[1], err)
}
iface, err := net.InterfaceByIndex(peerIfIndex)
if err != nil {
return "", err
}
return iface.Name, nil
}
func setUpInterface(ifName string) error {
glog.V(3).Infof("Enabling hairpin on interface %s", ifName)
ifPath := path.Join(sysfsNetPath, ifName)
if _, err := os.Stat(ifPath); err != nil {
return err
}
brportPath := path.Join(ifPath, brportRelativePath)
if _, err := os.Stat(brportPath); err != nil && os.IsNotExist(err) {
// Device is not on a bridge, so doesn't need hairpin mode
return nil
}
hairpinModeFile := path.Join(brportPath, hairpinModeRelativePath)
return ioutil.WriteFile(hairpinModeFile, []byte(hairpinEnable), 0644)
}