Add integration test pkg

This integration pkg adds a framework for writing integration tests
aginst the libcontainer APIs

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

integration/doc.go

@@ -0,0 +1,2 @@
+// integration is used for integration testing of libcontainer
+package integration

integration/exec_test.go

@@ -0,0 +1,38 @@
+package integration
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestExecPS(t *testing.T) {
+	if testing.Short() {
+		return
+	}
+
+	rootfs, err := newRootFs()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer remove(rootfs)
+
+	config := newTemplateConfig(rootfs)
+	buffers, exitCode, err := runContainer(config, "", "ps")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if exitCode != 0 {
+		t.Fatalf("exit code not 0. code %d stderr %q", exitCode, buffers.Stderr)
+	}
+
+	lines := strings.Split(buffers.Stdout.String(), "\n")
+	if len(lines) < 2 {
+		t.Fatalf("more than one process running for output %q", buffers.Stdout.String())
+	}
+	expected := `1 root     ps`
+	actual := strings.Trim(lines[1], "\n ")
+	if actual != expected {
+		t.Fatalf("expected output %q but received %q", expected, actual)
+	}
+}

integration/init_test.go

@@ -0,0 +1,39 @@
+package integration
+
+import (
+	"log"
+	"os"
+	"runtime"
+
+	"github.com/docker/libcontainer/namespaces"
+	"github.com/docker/libcontainer/syncpipe"
+)
+
+// init runs the libcontainer initialization code because of the busybox style needs
+// to work around the go runtime and the issues with forking
+func init() {
+	if len(os.Args) < 2 || os.Args[1] != "init" {
+		return
+	}
+	runtime.LockOSThread()
+
+	container, err := loadConfig()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	rootfs, err := os.Getwd()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	syncPipe, err := syncpipe.NewSyncPipeFromFd(0, 3)
+	if err != nil {
+		log.Fatalf("unable to create sync pipe: %s", err)
+	}
+
+	if err := namespaces.Init(container, rootfs, "", syncPipe, os.Args[3:]); err != nil {
+		log.Fatalf("unable to initialize for container: %s", err)
+	}
+	os.Exit(1)
+}

integration/template_test.go

@@ -0,0 +1,64 @@
+package integration
+
+import (
+	"github.com/docker/libcontainer"
+	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/devices"
+)
+
+// newTemplateConfig returns a base template for running a container
+//
+// it uses a network strategy of just setting a loopback interface
+// and the default setup for devices
+func newTemplateConfig(rootfs string) *libcontainer.Config {
+	return &libcontainer.Config{
+		RootFs: rootfs,
+		Tty:    false,
+		Capabilities: []string{
+			"CHOWN",
+			"DAC_OVERRIDE",
+			"FSETID",
+			"FOWNER",
+			"MKNOD",
+			"NET_RAW",
+			"SETGID",
+			"SETUID",
+			"SETFCAP",
+			"SETPCAP",
+			"NET_BIND_SERVICE",
+			"SYS_CHROOT",
+			"KILL",
+			"AUDIT_WRITE",
+		},
+		Namespaces: map[string]bool{
+			"NEWNS":  true,
+			"NEWUTS": true,
+			"NEWIPC": true,
+			"NEWPID": true,
+			"NEWNET": true,
+		},
+		Cgroups: &cgroups.Cgroup{
+			Parent:          "integration",
+			AllowAllDevices: false,
+			AllowedDevices:  devices.DefaultAllowedDevices,
+		},
+
+		MountConfig: &libcontainer.MountConfig{
+			DeviceNodes: devices.DefaultAutoCreatedDevices,
+		},
+		Hostname: "integration",
+		Env: []string{
+			"HOME=/root",
+			"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+			"HOSTNAME=integration",
+			"TERM=xterm",
+		},
+		Networks: []*libcontainer.Network{
+			{
+				Type:    "loopback",
+				Address: "127.0.0.1/0",
+				Gateway: "localhost",
+			},
+		},
+	}
+}

integration/utils_test.go

@@ -0,0 +1,95 @@
+package integration
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/docker/libcontainer"
+	"github.com/docker/libcontainer/namespaces"
+)
+
+func newStdBuffers() *stdBuffers {
+	return &stdBuffers{
+		Stdin:  bytes.NewBuffer(nil),
+		Stdout: bytes.NewBuffer(nil),
+		Stderr: bytes.NewBuffer(nil),
+	}
+}
+
+type stdBuffers struct {
+	Stdin  *bytes.Buffer
+	Stdout *bytes.Buffer
+	Stderr *bytes.Buffer
+}
+
+func writeConfig(config *libcontainer.Config) error {
+	f, err := os.OpenFile(filepath.Join(config.RootFs, "container.json"), os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0700)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	return json.NewEncoder(f).Encode(config)
+}
+
+func loadConfig() (*libcontainer.Config, error) {
+	f, err := os.Open(filepath.Join(os.Getenv("data_path"), "container.json"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	var container *libcontainer.Config
+	if err := json.NewDecoder(f).Decode(&container); err != nil {
+		return nil, err
+	}
+	return container, nil
+}
+
+// newRootFs creates a new tmp directory and copies the busybox root filesystem
+func newRootFs() (string, error) {
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		return "", err
+	}
+	if err := os.MkdirAll(dir, 0700); err != nil {
+		return "", err
+	}
+	if err := copyBusybox(dir); err != nil {
+		return "", nil
+	}
+	return dir, nil
+}
+
+func remove(dir string) {
+	os.RemoveAll(dir)
+}
+
+// copyBusybox copies the rootfs for a busybox container created for the test image
+// into the new directory for the specific test
+func copyBusybox(dest string) error {
+	out, err := exec.Command("sh", "-c", fmt.Sprintf("cp -R /busybox/* %s/", dest)).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("copy error %q: %q", err, out)
+	}
+	return nil
+}
+
+// runContainer runs the container with the specific config and arguments
+//
+// buffers are returned containing the STDOUT and STDERR output for the run
+// along with the exit code and any go error
+func runContainer(config *libcontainer.Config, console string, args ...string) (buffers *stdBuffers, exitCode int, err error) {
+	if err := writeConfig(config); err != nil {
+		return nil, -1, err
+	}
+
+	buffers = newStdBuffers()
+	exitCode, err = namespaces.Exec(config, buffers.Stdin, buffers.Stdout, buffers.Stderr,
+		console, config.RootFs, args, namespaces.DefaultCreateCommand, nil)
+	return
+}

utils/utils_test.go

@@ -0,0 +1,15 @@
+package utils
+
+import "testing"
+
+func TestGenerateName(t *testing.T) {
+	name, err := GenerateRandomName("veth", 5)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := 5 + len("veth")
+	if len(name) != 5+len("veth") {
+		t.Fatalf("expected name to be %d chars but received %d", expected, len(name))
+	}
+}