plugins: add plugins from containernetworking/cni

Plugins prepared from the containernetworking/cni repo as follows:

1) git reset --hard 1a9288c3c0
2) git remove everything not in plugins/
3) git remove plugins/test
4) git merge into containernetworking/plugins repo
5) adjust import paths for containernetworking/cni -> containernetworking/plugins

plugins/main/loopback/loopback.go

@@ -0,0 +1,72 @@
+// 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/ns"
+	"github.com/containernetworking/cni/pkg/skel"
+	"github.com/containernetworking/cni/pkg/types/current"
+	"github.com/containernetworking/cni/pkg/version"
+	"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)
+}

plugins/main/loopback/loopback_suite_test.go

@@ -0,0 +1,41 @@
+// 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_test
+
+import (
+	"github.com/onsi/gomega/gexec"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+var pathToLoPlugin string
+
+func TestLoopback(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Loopback Suite")
+}
+
+var _ = BeforeSuite(func() {
+	var err error
+	pathToLoPlugin, err = gexec.Build("github.com/containernetworking/plugins/plugins/main/loopback")
+	Expect(err).NotTo(HaveOccurred())
+})
+
+var _ = AfterSuite(func() {
+	gexec.CleanupBuildArtifacts()
+})

plugins/main/loopback/loopback_test.go

@@ -0,0 +1,100 @@
+// 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_test
+
+import (
+	"fmt"
+	"net"
+	"os/exec"
+	"strings"
+
+	"github.com/containernetworking/cni/pkg/ns"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gbytes"
+	"github.com/onsi/gomega/gexec"
+)
+
+var _ = Describe("Loopback", func() {
+	var (
+		networkNS   ns.NetNS
+		containerID string
+		command     *exec.Cmd
+		environ     []string
+	)
+
+	BeforeEach(func() {
+		command = exec.Command(pathToLoPlugin)
+
+		var err error
+		networkNS, err = ns.NewNS()
+		Expect(err).NotTo(HaveOccurred())
+
+		environ = []string{
+			fmt.Sprintf("CNI_CONTAINERID=%s", containerID),
+			fmt.Sprintf("CNI_NETNS=%s", networkNS.Path()),
+			fmt.Sprintf("CNI_IFNAME=%s", "this is ignored"),
+			fmt.Sprintf("CNI_ARGS=%s", "none"),
+			fmt.Sprintf("CNI_PATH=%s", "/some/test/path"),
+		}
+		command.Stdin = strings.NewReader(`{ "cniVersion": "0.1.0" }`)
+	})
+
+	AfterEach(func() {
+		Expect(networkNS.Close()).To(Succeed())
+	})
+
+	Context("when given a network namespace", func() {
+		It("sets the lo device to UP", func() {
+			command.Env = append(environ, fmt.Sprintf("CNI_COMMAND=%s", "ADD"))
+
+			session, err := gexec.Start(command, GinkgoWriter, GinkgoWriter)
+			Expect(err).NotTo(HaveOccurred())
+
+			Eventually(session).Should(gbytes.Say(`{.*}`))
+			Eventually(session).Should(gexec.Exit(0))
+
+			var lo *net.Interface
+			err = networkNS.Do(func(ns.NetNS) error {
+				var err error
+				lo, err = net.InterfaceByName("lo")
+				return err
+			})
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(lo.Flags & net.FlagUp).To(Equal(net.FlagUp))
+		})
+
+		It("sets the lo device to DOWN", func() {
+			command.Env = append(environ, fmt.Sprintf("CNI_COMMAND=%s", "DEL"))
+
+			session, err := gexec.Start(command, GinkgoWriter, GinkgoWriter)
+			Expect(err).NotTo(HaveOccurred())
+
+			Eventually(session).Should(gbytes.Say(``))
+			Eventually(session).Should(gexec.Exit(0))
+
+			var lo *net.Interface
+			err = networkNS.Do(func(ns.NetNS) error {
+				var err error
+				lo, err = net.InterfaceByName("lo")
+				return err
+			})
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(lo.Flags & net.FlagUp).NotTo(Equal(net.FlagUp))
+		})
+	})
+})