testing: test invocation of newer plugins with an older libcni

libcni/backwards_compatibility_test.go

@@ -17,12 +17,14 @@ package libcni_test
 import (
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
 
 	"github.com/containernetworking/cni/libcni"
 	"github.com/containernetworking/cni/pkg/version/legacy_examples"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gexec"
 )
 
 var _ = Describe("Backwards compatibility", func() {
@@ -50,4 +52,17 @@ var _ = Describe("Backwards compatibility", func() {
 
 		Expect(os.RemoveAll(pluginPath)).To(Succeed())
 	})
+
+	It("correctly handles the request from a legacy libcni", func() {
+		example := legacy_examples.V010_Client
+
+		binPath, err := example.Build()
+		Expect(err).NotTo(HaveOccurred())
+
+		cmd := exec.Command(binPath)
+
+		session, err := gexec.Start(cmd, GinkgoWriter, GinkgoWriter)
+		Expect(err).NotTo(HaveOccurred())
+		Eventually(session).Should(gexec.Exit(0))
+	})
 })

pkg/version/legacy_examples/example_client.go

@@ -0,0 +1,134 @@
+// 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 legacy_examples
+
+// An ExampleInvoker is a git reference to the CNI repo and a Golang CNI
+// plugin invoker that builds against that version of the repo
+// In other words, it tests forward-compatability
+//
+// The invoker source should basically be a simplistic cnitool. It will execute
+// a noop plugin provided as argv[1]
+type ExampleClient struct {
+	Example
+}
+
+// A lot of this is borrowed from the ptp test. Consider refactoring
+// This tests a non-versioned network config
+var V010_Client = ExampleClient{
+	Example{
+		Name:          "example_invoker_v010",
+		CNIRepoGitRef: "c0d34c69", //version with ns.Do
+		PluginSource: `package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"net"
+
+	"github.com/containernetworking/cni/pkg/ns"
+	"github.com/containernetworking/cni/libcni"
+)
+
+func main(){
+	code :=	exec()
+	os.Exit(code)
+}
+
+func exec() int {
+	confStr := "{ \"name\": \"default\", \"type\":\"ptp\", \"ipam\":{ \"type\": \"host-local\", \"subnet\": \"10.1.2.0/24\"}}"
+	netConf, err := libcni.ConfFromBytes([]byte(confStr))
+	if err != nil {
+		fmt.Printf("could not parse netconfig: %+v", err)
+		return 1
+	}
+
+	targetNs, err := ns.NewNS()
+	if err !=  nil {
+		fmt.Printf("Could not create ns: %+v", err)
+		return 1
+	}
+	defer targetNs.Close()
+
+	ifName := "eth0"
+
+	runtimeConf := &libcni.RuntimeConf{
+		ContainerID: "some-container-id",
+		NetNS:       targetNs.Path(),
+		IfName:      ifName,
+	}
+
+	cniConfig := &libcni.CNIConfig{Path: strings.Split(os.Getenv("PATH"), ":")}
+
+	result, err := cniConfig.AddNetwork(netConf, runtimeConf)
+	fmt.Printf("Result: %+v", result)
+	if err != nil {
+		fmt.Printf("noop add failed: %+v", err)
+		return 2
+	}
+
+	expectedIP := result.IP4.IP
+
+	err = targetNs.Do(func(ns.NetNS) error {
+		netif, err := net.InterfaceByName(ifName)
+		if err != nil {
+			return fmt.Errorf("could not retrieve interface: %v", err)
+		}
+
+		addrs, err := netif.Addrs()
+		if err != nil {
+			return fmt.Errorf("could not retrieve addresses, %+v", err)
+		}
+
+		found := false
+		for _, addr := range addrs {
+			if addr.String() == expectedIP.String() {
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			return fmt.Errorf("Far-side link did not have expected address %s", expectedIP)
+		}
+		return nil
+	})
+	if err != nil {
+		fmt.Println(err)
+		return 4
+	}
+
+	err = cniConfig.DelNetwork(netConf, runtimeConf)
+	if err != nil {
+		fmt.Printf("error deleting network: %v", err)
+		return 5
+	}
+
+	err = targetNs.Do(func(ns.NetNS) error {
+		_, err := net.InterfaceByName(ifName)
+		if err == nil {
+			return fmt.Errorf("interface was not deleted")
+		}
+		return nil
+	})
+	if err != nil {
+		fmt.Println(err)
+		return 6
+	}
+
+	return 0
+}
+`,
+	}}