README
¶
netns - network namespaces in go
The netns package provides an ultra-simple interface for handling network namespaces in go. Changing namespaces requires elevated privileges, so in most cases this code needs to be run as root.
Local Build and Test
You can use go get command:
go get github.com/vishvananda/netns
Testing (requires root):
sudo -E go test github.com/vishvananda/netns
Example
package main
import (
"fmt"
"net"
"runtime"
"github.com/vishvananda/netns"
)
func main() {
// Lock the OS Thread so we don't accidentally switch namespaces
runtime.LockOSThread()
defer runtime.UnlockOSThread()
// Save the current network namespace
origns, _ := netns.Get()
defer origns.Close()
// Create a new network namespace
newns, _ := netns.New()
defer newns.Close()
// Do something with the network namespace
ifaces, _ := net.Interfaces()
fmt.Printf("Interfaces: %v\n", ifaces)
// Switch back to the original namespace
netns.Set(origns)
}
NOTE
The library can be safely used only with Go >= 1.10 due to golang/go#20676.
After locking a goroutine to its current OS thread with runtime.LockOSThread()
and changing its network namespace, any new subsequent goroutine won't be
scheduled on that thread while it's locked. Therefore, the new goroutine
will run in a different namespace leading to unexpected results.
See here for more details.
Documentation
¶
Overview ¶
Package netns allows ultra-simple network namespace handling. NsHandles can be retrieved and set. Note that the current namespace is thread local so actions that set and reset namespaces should use LockOSThread to make sure the namespace doesn't change due to a goroutine switch. It is best to close NsHandles when you are done with them. This can be accomplished via a `defer ns.Close()` on the handle. Changing namespaces requires elevated privileges, so in most cases this code needs to be run as root.
Index ¶
- Variables
- func DeleteNamed(name string) error
- func Set(ns NsHandle) (err error)
- func Setns(ns NsHandle, nstype int) (err error)
- type NsHandle
- func Get() (NsHandle, error)
- func GetFromDocker(id string) (NsHandle, error)
- func GetFromName(name string) (NsHandle, error)
- func GetFromPath(path string) (NsHandle, error)
- func GetFromPid(pid int) (NsHandle, error)
- func GetFromThread(pid, tid int) (NsHandle, error)
- func New() (ns NsHandle, err error)
- func NewNamed(name string) (NsHandle, error)
- func None() NsHandle
Constants ¶
This section is empty.
Variables ¶
var (
ErrNotImplemented = errors.New("not implemented")
)
Functions ¶
func DeleteNamed ¶
Types ¶
type NsHandle ¶
type NsHandle int
NsHandle is a handle to a network namespace. It can be cast directly to an int and used as a file descriptor.
func GetFromDocker ¶
func GetFromName ¶
func GetFromPath ¶
func GetFromPid ¶
func GetFromThread ¶
func (*NsHandle) Close ¶
Close closes the NsHandle and resets its file descriptor to -1. It is not safe to use an NsHandle after Close() is called.
func (NsHandle) Equal ¶
Equal determines if two network handles refer to the same network namespace. This is done by comparing the device and inode that the file descriptors point to.
Source Files