Add apiserver launcher to test framework

To start an apiserver:

```
apiServer := APIServer{Path: "/path/to/my/apiserver/binary"}
session, err := apiServer.Start("tcp://whereever.is.my.etcd:port")
Expect(err).NotTo(HaveOccurred())
```

When you're done testing against that apiserver:

```
session.Terminate().Wait()
```

...or if you prefer:

```
gexec.Terminate()
```

...which will terminate not only this apiserver, but also all other
command sessions you started in this test.

pkg/framework/test/apiserver.go

@@ -0,0 +1,35 @@
+package test
+
+import (
+	"os/exec"
+
+	"fmt"
+
+	"github.com/onsi/ginkgo"
+	"github.com/onsi/gomega/gexec"
+)
+
+// APIServer knows how to run a kubernetes apiserver. Set it up with the path to a precompiled binary.
+type APIServer struct {
+	// The path to the apiserver binary
+	Path string
+}
+
+// Start starts the apiserver, and returns a gexec.Session. To stop it again, call Terminate and Wait on that session.
+func (s APIServer) Start(etcdURL string) (*gexec.Session, error) {
+	args := []string{
+		"--authorization-mode=Node,RBAC",
+		"--runtime-config=admissionregistration.k8s.io/v1alpha1",
+		"--v=3", "--vmodule=",
+		"--admission-control=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,SecurityContextDeny,DefaultStorageClass,DefaultTolerationSeconds,GenericAdmissionWebhook,ResourceQuota",
+		"--admission-control-config-file=",
+		"--bind-address=0.0.0.0",
+		"--insecure-bind-address=127.0.0.1",
+		"--insecure-port=8080",
+		"--storage-backend=etcd3",
+		fmt.Sprintf("--etcd-servers=%s", etcdURL),
+	}
+
+	command := exec.Command(s.Path, args...)
+	return gexec.Start(command, ginkgo.GinkgoWriter, ginkgo.GinkgoWriter)
+}

pkg/framework/test/apiserver_test.go

@@ -0,0 +1,51 @@
+package test_test
+
+import (
+	. "k8s.io/kubectl/pkg/framework/test"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gbytes"
+	"github.com/onsi/gomega/gexec"
+)
+
+var _ = Describe("Apiserver", func() {
+
+	Context("when given a path to a binary that runs for a long time", func() {
+		It("can start and stop that binary", func() {
+			pathToFakeAPIServer, err := gexec.Build("k8s.io/kubectl/pkg/framework/test/assets/fakeapiserver")
+			Expect(err).NotTo(HaveOccurred())
+			apiServer := APIServer{Path: pathToFakeAPIServer}
+
+			By("Starting the API Server")
+			session, err := apiServer.Start("the etcd url")
+			Expect(err).NotTo(HaveOccurred())
+
+			Eventually(session.Out).Should(gbytes.Say("Everything is fine"))
+			Expect(session).NotTo(gexec.Exit())
+
+			By("Stopping the API Server")
+			session.Terminate()
+			Eventually(session).Should(gexec.Exit(143))
+		})
+
+	})
+
+	Context("when no path is given", func() {
+		It("fails with a helpful error", func() {
+			apiServer := APIServer{}
+			_, err := apiServer.Start("the etcd url")
+			Expect(err).To(MatchError(ContainSubstring("no such file or directory")))
+		})
+	})
+
+	Context("when given a path to a non-executable", func() {
+		It("fails with a helpful error", func() {
+			apiServer := APIServer{
+				Path: "./apiserver.go",
+			}
+			_, err := apiServer.Start("the etcd url")
+			Expect(err).To(MatchError(ContainSubstring("./apiserver.go: permission denied")))
+		})
+	})
+})

pkg/framework/test/assets/fakeapiserver/apiserver.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+func main() {
+	expectedArgs := []string{
+		"--authorization-mode=Node,RBAC",
+		"--runtime-config=admissionregistration.k8s.io/v1alpha1",
+		"--v=3", "--vmodule=",
+		"--admission-control=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,SecurityContextDeny,DefaultStorageClass,DefaultTolerationSeconds,GenericAdmissionWebhook,ResourceQuota",
+		"--admission-control-config-file=",
+		"--bind-address=0.0.0.0",
+		"--insecure-bind-address=127.0.0.1",
+		"--insecure-port=8080",
+		"--storage-backend=etcd3",
+		"--etcd-servers=the etcd url",
+	}
+
+	for i, arg := range os.Args[1:] {
+		if arg != expectedArgs[i] {
+			fmt.Printf("Expected arg %s, got arg %s", expectedArgs[i], arg)
+			os.Exit(1)
+		}
+	}
+	fmt.Println("Everything is fine")
+
+	time.Sleep(10 * time.Minute)
+}

pkg/framework/test/test_suite_test.go

@@ -0,0 +1,13 @@
+package test_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestTest(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Test Suite")
+}