plugins: adds new no-op plugin that may be used as a test-double

Plugin can be configured to record all inputs and to respond with
arbitrary stdout or error message.  Will support upcoming integration
testing.

build

@@ -20,7 +20,7 @@ echo "Building reference CLI"
 go install "$@" ${REPO_PATH}/cnitool
 
 echo "Building plugins"
-PLUGINS="plugins/meta/* plugins/main/* plugins/ipam/*"
+PLUGINS="plugins/meta/* plugins/main/* plugins/ipam/* plugins/test/*"
 for d in $PLUGINS; do
 	if [ -d $d ]; then
 		plugin=$(basename $d)

pkg/testutils/bad_reader.go

@@ -16,6 +16,7 @@ package testutils
 
 import "errors"
 
+// BadReader is an io.Reader which always errors
 type BadReader struct {
 	Error error
 }

plugins/test/noop/debug/debug.go

@@ -0,0 +1,62 @@
+// 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.
+
+// debug supports tests that use the noop plugin
+package debug
+
+import (
+	"encoding/json"
+	"io/ioutil"
+
+	"github.com/containernetworking/cni/pkg/skel"
+)
+
+// Debug is used to control and record the behavior of the noop plugin
+type Debug struct {
+	ReportResult string
+	ReportError  string
+	Command      string
+	CmdArgs      skel.CmdArgs
+}
+
+// ReadDebug will return a debug file recorded by the noop plugin
+func ReadDebug(debugFilePath string) (*Debug, error) {
+	debugBytes, err := ioutil.ReadFile(debugFilePath)
+	if err != nil {
+		return nil, err
+	}
+
+	var debug Debug
+	err = json.Unmarshal(debugBytes, &debug)
+	if err != nil {
+		return nil, err
+	}
+
+	return &debug, nil
+}
+
+// WriteDebug will create a debug file to control the noop plugin
+func (debug *Debug) WriteDebug(debugFilePath string) error {
+	debugBytes, err := json.Marshal(debug)
+	if err != nil {
+		return err
+	}
+
+	err = ioutil.WriteFile(debugFilePath, debugBytes, 0600)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

plugins/test/noop/main.go

@@ -0,0 +1,73 @@
+// 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.
+
+/*
+Noop plugin is a CNI plugin designed for use as a test-double.
+
+When calling, set the CNI_ARGS env var equal to the path of a file containing
+the JSON encoding of a Debug.
+*/
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/containernetworking/cni/pkg/skel"
+	"github.com/containernetworking/cni/plugins/test/noop/debug"
+)
+
+func debugBehavior(args *skel.CmdArgs, command string) error {
+	if !strings.HasPrefix(args.Args, "DEBUG=") {
+		fmt.Printf(`{}`)
+		os.Stderr.WriteString("CNI_ARGS empty, no debug behavior\n")
+		return nil
+	}
+	debugFilePath := strings.TrimPrefix(args.Args, "DEBUG=")
+	debug, err := debug.ReadDebug(debugFilePath)
+	if err != nil {
+		return err
+	}
+
+	debug.CmdArgs = *args
+	debug.Command = command
+
+	err = debug.WriteDebug(debugFilePath)
+	if err != nil {
+		return err
+	}
+
+	if debug.ReportError != "" {
+		return errors.New(debug.ReportError)
+	} else {
+		os.Stdout.WriteString(debug.ReportResult)
+	}
+
+	return nil
+}
+
+func cmdAdd(args *skel.CmdArgs) error {
+	return debugBehavior(args, "ADD")
+}
+
+func cmdDel(args *skel.CmdArgs) error {
+	return debugBehavior(args, "DEL")
+}
+
+func main() {
+	skel.PluginMain(cmdAdd, cmdDel)
+}

plugins/test/noop/noop_suite_test.go

@@ -0,0 +1,45 @@
+// 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/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gexec"
+
+	"testing"
+)
+
+func TestNoop(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "No-op plugin Suite")
+}
+
+const packagePath = "github.com/containernetworking/cni/plugins/test/noop"
+
+var pathToPlugin string
+
+var _ = SynchronizedBeforeSuite(func() []byte {
+	var err error
+	pathToPlugin, err = gexec.Build(packagePath)
+	Expect(err).NotTo(HaveOccurred())
+	return []byte(pathToPlugin)
+}, func(crossNodeData []byte) {
+	pathToPlugin = string(crossNodeData)
+})
+
+var _ = SynchronizedAfterSuite(func() {}, func() {
+	gexec.CleanupBuildArtifacts()
+})

plugins/test/noop/noop_test.go

@@ -0,0 +1,135 @@
+// 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 (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/containernetworking/cni/pkg/skel"
+	noop_debug "github.com/containernetworking/cni/plugins/test/noop/debug"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gexec"
+)
+
+var _ = Describe("No-op plugin", func() {
+	var (
+		cmd           *exec.Cmd
+		debugFileName string
+		debug         *noop_debug.Debug
+	)
+
+	BeforeEach(func() {
+		debug = &noop_debug.Debug{
+			ReportResult: `{ "ip4": { "ip": "10.1.2.3/24" }, "dns": {} }`,
+		}
+
+		debugFile, err := ioutil.TempFile("", "cni_debug")
+		Expect(err).NotTo(HaveOccurred())
+		Expect(debugFile.Close()).To(Succeed())
+		debugFileName = debugFile.Name()
+
+		Expect(debug.WriteDebug(debugFileName)).To(Succeed())
+
+		cmd = exec.Command(pathToPlugin)
+		cmd.Env = []string{
+			"CNI_COMMAND=ADD",
+			"CNI_CONTAINERID=some-container-id",
+			"CNI_ARGS=DEBUG=" + debugFile.Name(),
+			"CNI_NETNS=/some/netns/path",
+			"CNI_IFNAME=some-eth0",
+			"CNI_PATH=/some/bin/path",
+		}
+		cmd.Stdin = strings.NewReader(`{"some":"stdin-json"}`)
+	})
+
+	AfterEach(func() {
+		os.Remove(debugFileName)
+	})
+
+	It("responds to ADD using the ReportResult debug field", func() {
+		session, err := gexec.Start(cmd, GinkgoWriter, GinkgoWriter)
+		Expect(err).NotTo(HaveOccurred())
+		Eventually(session).Should(gexec.Exit(0))
+		Expect(session.Out.Contents()).To(MatchJSON(`{
+				 "ip4": { "ip": "10.1.2.3/24" },
+				 "dns": {}
+      }`))
+	})
+
+	It("records all the args provided by skel.PluginMain", func() {
+		session, err := gexec.Start(cmd, GinkgoWriter, GinkgoWriter)
+		Expect(err).NotTo(HaveOccurred())
+		Eventually(session).Should(gexec.Exit(0))
+
+		debug, err := noop_debug.ReadDebug(debugFileName)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(debug.Command).To(Equal("ADD"))
+		Expect(debug.CmdArgs).To(Equal(skel.CmdArgs{
+			ContainerID: "some-container-id",
+			Netns:       "/some/netns/path",
+			IfName:      "some-eth0",
+			Args:        "DEBUG=" + debugFileName,
+			Path:        "/some/bin/path",
+			StdinData:   []byte(`{"some":"stdin-json"}`),
+		}))
+	})
+
+	Context("when the ReportError debug field is set", func() {
+		BeforeEach(func() {
+			debug.ReportError = "banana"
+			Expect(debug.WriteDebug(debugFileName)).To(Succeed())
+		})
+
+		It("returns an error to skel.PluginMain, causing the process to exit code 1", func() {
+			session, err := gexec.Start(cmd, GinkgoWriter, GinkgoWriter)
+			Expect(err).NotTo(HaveOccurred())
+			Eventually(session).Should(gexec.Exit(1))
+			Expect(session.Out.Contents()).To(MatchJSON(`{ "code": 100, "msg": "banana" }`))
+		})
+	})
+
+	Context("when the CNI_COMMAND is DEL", func() {
+		BeforeEach(func() {
+			cmd.Env[0] = "CNI_COMMAND=DEL"
+			debug.ReportResult = `{ "some": "delete-data" }`
+			Expect(debug.WriteDebug(debugFileName)).To(Succeed())
+		})
+
+		It("still does all the debug behavior", func() {
+			session, err := gexec.Start(cmd, GinkgoWriter, GinkgoWriter)
+			Expect(err).NotTo(HaveOccurred())
+			Eventually(session).Should(gexec.Exit(0))
+			Expect(session.Out.Contents()).To(MatchJSON(`{
+				"some": "delete-data"
+      }`))
+			debug, err := noop_debug.ReadDebug(debugFileName)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(debug.Command).To(Equal("DEL"))
+			Expect(debug.CmdArgs).To(Equal(skel.CmdArgs{
+				ContainerID: "some-container-id",
+				Netns:       "/some/netns/path",
+				IfName:      "some-eth0",
+				Args:        "DEBUG=" + debugFileName,
+				Path:        "/some/bin/path",
+				StdinData:   []byte(`{"some":"stdin-json"}`),
+			}))
+		})
+
+	})
+})

test

@@ -11,8 +11,8 @@ set -e
 
 source ./build
 
-TESTABLE="plugins/ipam/dhcp plugins/ipam/host-local plugins/main/loopback pkg/invoke pkg/ns pkg/skel pkg/types pkg/utils plugins/main/ipvlan plugins/main/macvlan plugins/main/bridge plugins/main/ptp"
+TESTABLE="plugins/ipam/dhcp plugins/ipam/host-local plugins/main/loopback pkg/invoke pkg/ns pkg/skel pkg/types pkg/utils plugins/main/ipvlan plugins/main/macvlan plugins/main/bridge plugins/main/ptp plugins/test/noop"
-FORMATTABLE="$TESTABLE libcni pkg/ip pkg/ipam pkg/testutils plugins/ipam/host-local plugins/main/bridge plugins/meta/flannel plugins/meta/tuning"
+FORMATTABLE="$TESTABLE libcni pkg/ip pkg/ipam pkg/testutils plugins/meta/flannel plugins/meta/tuning"
 
 # user has not provided PKG override
 if [ -z "$PKG" ]; then