add DHCP IPAM plugin

The plugin binary actually functions in two modes. The first mode
is a regular CNI plugin. The second mode (when stared with "daemon" arg)
runs a DHCP client daemon. When executed as a CNI plugin, it issues
an RPC request to the daemon for actual processing. The daemon is
required since a DHCP lease needs to be maintained by periodically
renewing it. One instance of the daemon can server arbitrary number
of containers/leases.
This commit is contained in:
Eugene Yakubovich 2015-05-19 12:02:41 -07:00
parent e59e2fd890
commit a6a822268c

View File

@ -48,19 +48,30 @@ func SetNS(f *os.File, flags uintptr) error {
// WithNetNSPath executes the passed closure under the given network
// namespace, restoring the original namespace afterwards.
func WithNetNSPath(nspath string, f func(*os.File) error) error {
// Changing namespaces must be done on a goroutine that has been
// locked to an OS thread. If lockThread arg is true, this function
// locks the goroutine prior to change namespace and unlocks before
// returning
func WithNetNSPath(nspath string, lockThread bool, f func(*os.File) error) error {
ns, err := os.Open(nspath)
if err != nil {
return fmt.Errorf("Failed to open %v: %v", nspath, err)
}
defer ns.Close()
return WithNetNS(ns, f)
return WithNetNS(ns, lockThread, f)
}
// WithNetNS executes the passed closure under the given network
// namespace, restoring the original namespace afterwards.
func WithNetNS(ns *os.File, f func(*os.File) error) error {
// Changing namespaces must be done on a goroutine that has been
// locked to an OS thread. If lockThread arg is true, this function
// locks the goroutine prior to change namespace and unlocks before
// returning
func WithNetNS(ns *os.File, lockThread bool, f func(*os.File) error) error {
if lockThread {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
}
// save a handle to current (host) network namespace
thisNS, err := os.Open("/proc/self/ns/net")
if err != nil {