Test Start() function

... with some integrationy unit tests

pkg/framework/test/internal/process.go

@@ -28,7 +28,7 @@ func Start(command *exec.Cmd, startMessage string, startTimeout time.Duration) (
 	detectedStart := stdErr.Detect(startMessage)
 	timedOut := time.After(startTimeout)
 
-	session, err := gexec.Start(command, gbytes.NewBuffer(), stdErr)
+	session, err := gexec.Start(command, nil, stdErr)
 	if err != nil {
 		return session, err
 	}
@@ -37,7 +37,8 @@ func Start(command *exec.Cmd, startMessage string, startTimeout time.Duration) (
 	case <-detectedStart:
 		return session, nil
 	case <-timedOut:
-		return session, fmt.Errorf("timeout waiting for apiserver to start serving")
+		session.Terminate()
+		return session, fmt.Errorf("timeout waiting for process to start serving")
 	}
 
 }

pkg/framework/test/internal/process_test.go

@@ -0,0 +1,68 @@
+package internal_test
+
+import (
+	. "k8s.io/kubectl/pkg/framework/test/internal"
+
+	"os/exec"
+
+	"time"
+
+	"os"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Start", func() {
+	var (
+		command *exec.Cmd
+		timeout time.Duration
+	)
+	BeforeEach(func() {
+		command = getSimpleCommand()
+		timeout = 200 * time.Millisecond
+	})
+
+	It("can start a process", func() {
+		timeout = 5 * time.Second
+		session, err := Start(command, "loop 3", timeout)
+
+		Expect(err).NotTo(HaveOccurred())
+		Consistently(session.ExitCode).Should(BeNumerically("==", -1))
+	})
+
+	Context("when process takes too long to start", func() {
+		It("returns an timeout error", func() {
+			session, err := Start(command, "loop 3000", timeout)
+
+			Expect(err).To(MatchError(ContainSubstring("timeout")))
+			Eventually(session.ExitCode, 10).Should(BeNumerically("==", 143))
+		})
+	})
+
+	Context("when command cannot be started", func() {
+		BeforeEach(func() {
+			command = exec.Command("/notexistent")
+		})
+		It("propagates the error", func() {
+			_, err := Start(command, "does not matter", timeout)
+
+			Expect(os.IsNotExist(err)).To(BeTrue())
+		})
+	})
+})
+
+func getSimpleCommand() *exec.Cmd {
+	return exec.Command(
+		"bash", "-c",
+		`
+			i=0
+			while true
+			do
+				echo "loop $i" >&2
+				let 'i += 1'
+				sleep 0.2
+			done
+		`,
+	)
+}