pkg/invoke: refactor plugin exec and backfill unit tests

pkg/invoke/raw_exec_test.go

@@ -0,0 +1,123 @@
+// 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 invoke_test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+
+	"github.com/containernetworking/cni/pkg/invoke"
+
+	noop_debug "github.com/containernetworking/cni/plugins/test/noop/debug"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("RawExec", func() {
+	var (
+		debugFileName string
+		debug         *noop_debug.Debug
+		environ       []string
+		stdin         []byte
+		execer        *invoke.RawExec
+	)
+
+	const reportResult = `{ "some": "result" }`
+
+	BeforeEach(func() {
+		debugFile, err := ioutil.TempFile("", "cni_debug")
+		Expect(err).NotTo(HaveOccurred())
+		Expect(debugFile.Close()).To(Succeed())
+		debugFileName = debugFile.Name()
+
+		debug = &noop_debug.Debug{
+			ReportResult: reportResult,
+			ReportStderr: "some stderr message",
+		}
+		Expect(debug.WriteDebug(debugFileName)).To(Succeed())
+
+		environ = []string{
+			"CNI_COMMAND=ADD",
+			"CNI_CONTAINERID=some-container-id",
+			"CNI_ARGS=DEBUG=" + debugFileName,
+			"CNI_NETNS=/some/netns/path",
+			"CNI_PATH=/some/bin/path",
+			"CNI_IFNAME=some-eth0",
+		}
+		stdin = []byte(`{"some":"stdin-json"}`)
+		execer = &invoke.RawExec{}
+	})
+
+	AfterEach(func() {
+		Expect(os.Remove(debugFileName)).To(Succeed())
+	})
+
+	It("runs the plugin with the given stdin and environment", func() {
+		_, err := execer.ExecPlugin(pathToPlugin, stdin, environ)
+		Expect(err).NotTo(HaveOccurred())
+
+		debug, err := noop_debug.ReadDebug(debugFileName)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(debug.Command).To(Equal("ADD"))
+		Expect(debug.CmdArgs.StdinData).To(Equal(stdin))
+		Expect(debug.CmdArgs.Netns).To(Equal("/some/netns/path"))
+	})
+
+	It("returns the resulting stdout as bytes", func() {
+		resultBytes, err := execer.ExecPlugin(pathToPlugin, stdin, environ)
+		Expect(err).NotTo(HaveOccurred())
+
+		Expect(resultBytes).To(BeEquivalentTo(reportResult))
+	})
+
+	Context("when the Stderr writer is set", func() {
+		var stderrBuffer *bytes.Buffer
+
+		BeforeEach(func() {
+			stderrBuffer = &bytes.Buffer{}
+			execer.Stderr = stderrBuffer
+		})
+
+		It("forwards any stderr bytes to the Stderr writer", func() {
+			_, err := execer.ExecPlugin(pathToPlugin, stdin, environ)
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(stderrBuffer.String()).To(Equal("some stderr message"))
+		})
+	})
+
+	Context("when the plugin errors", func() {
+		BeforeEach(func() {
+			debug.ReportError = "banana"
+			Expect(debug.WriteDebug(debugFileName)).To(Succeed())
+		})
+
+		It("wraps and returns the error", func() {
+			_, err := execer.ExecPlugin(pathToPlugin, stdin, environ)
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(MatchError("banana"))
+		})
+	})
+
+	Context("when the system is unable to execute the plugin", func() {
+		It("returns the error", func() {
+			_, err := execer.ExecPlugin("/tmp/some/invalid/plugin/path", stdin, environ)
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(MatchError(ContainSubstring("/tmp/some/invalid/plugin/path")))
+		})
+	})
+})