plugins/main/loopback/loopback.go

// Copyright 2016 CNI 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 main

import (
	"github.com/containernetworking/cni/pkg/skel"
	"github.com/containernetworking/cni/pkg/types/current"
	"github.com/containernetworking/cni/pkg/version"
	"github.com/containernetworking/plugins/pkg/ns"
	"github.com/vishvananda/netlink"
)

func cmdAdd(args *skel.CmdArgs) error {
	args.IfName = "lo" // ignore config, this only works for loopback
	err := ns.WithNetNSPath(args.Netns, func(_ ns.NetNS) error {
		link, err := netlink.LinkByName(args.IfName)
		if err != nil {
			return err // not tested
		}

		err = netlink.LinkSetUp(link)
		if err != nil {
			return err // not tested
		}

		return nil
	})
	if err != nil {
		return err // not tested
	}

	result := current.Result{}
	return result.Print()
}

func cmdDel(args *skel.CmdArgs) error {
	args.IfName = "lo" // ignore config, this only works for loopback
	err := ns.WithNetNSPath(args.Netns, func(ns.NetNS) error {
		link, err := netlink.LinkByName(args.IfName)
		if err != nil {
			return err // not tested
		}

		err = netlink.LinkSetDown(link)
		if err != nil {
			return err // not tested
		}

		return nil
	})
	if err != nil {
		return err // not tested
	}

	return nil
}

func main() {
	skel.PluginMain(cmdAdd, cmdDel, version.All)
}