Simplify Docker test infrastructure.

This change adds a layer of abstraction around the internal Docker APIs,
and eliminates all direct dependencies on Dockerfiles in the infrastructure.

A subsequent change will automated the generation of local images (with
efficient caching). Note that this change drops the use of bazel container
rules, as that experiment does not seem to be viable.

PiperOrigin-RevId: 308095430

11 files changed, 1564 insertions, 5 deletions

diff --git a/pkg/sentry/fsimpl/ext/BUILD b/pkg/sentry/fsimpl/ext/BUILD
index a4947c480..ff861d0fe 100644
--- a/pkg/sentry/fsimpl/ext/BUILD
+++ b/pkg/sentry/fsimpl/ext/BUILD
@@ -93,8 +93,8 @@ go_test(
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/vfs",
         "//pkg/syserror",
+        "//pkg/test/testutil",
         "//pkg/usermem",
-        "//runsc/testutil",
         "@com_github_google_go-cmp//cmp:go_default_library",
         "@com_github_google_go-cmp//cmp/cmpopts:go_default_library",
     ],
diff --git a/pkg/sentry/fsimpl/ext/ext_test.go b/pkg/sentry/fsimpl/ext/ext_test.go
index 29bb73765..64e9a579f 100644
--- a/pkg/sentry/fsimpl/ext/ext_test.go
+++ b/pkg/sentry/fsimpl/ext/ext_test.go
@@ -32,9 +32,8 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/syserror"
+	"gvisor.dev/gvisor/pkg/test/testutil"
 	"gvisor.dev/gvisor/pkg/usermem"
-
-	"gvisor.dev/gvisor/runsc/testutil"
 )
 
 const (
diff --git a/pkg/tcpip/transport/tcp/BUILD b/pkg/tcpip/transport/tcp/BUILD
index 61426623c..f2aa69069 100644
--- a/pkg/tcpip/transport/tcp/BUILD
+++ b/pkg/tcpip/transport/tcp/BUILD
@@ -105,8 +105,8 @@ go_test(
         "//pkg/tcpip/seqnum",
         "//pkg/tcpip/stack",
         "//pkg/tcpip/transport/tcp/testing/context",
+        "//pkg/test/testutil",
         "//pkg/waiter",
-        "//runsc/testutil",
     ],
 )
 
diff --git a/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go b/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go
index 359a75e73..5fe23113b 100644
--- a/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go
@@ -31,7 +31,7 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip/header"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp/testing/context"
-	"gvisor.dev/gvisor/runsc/testutil"
+	"gvisor.dev/gvisor/pkg/test/testutil"
 )
 
 func TestFastRecovery(t *testing.T) {
diff --git a/pkg/test/criutil/BUILD b/pkg/test/criutil/BUILD
new file mode 100644
index 000000000..a7b082cee
--- /dev/null
+++ b/pkg/test/criutil/BUILD
@@ -0,0 +1,14 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "criutil",
+    testonly = 1,
+    srcs = ["criutil.go"],
+    visibility = ["//:sandbox"],
+    deps = [
+        "//pkg/test/dockerutil",
+        "//pkg/test/testutil",
+    ],
+)
diff --git a/pkg/test/criutil/criutil.go b/pkg/test/criutil/criutil.go
new file mode 100644
index 000000000..bebebb48e
--- /dev/null
+++ b/pkg/test/criutil/criutil.go
@@ -0,0 +1,306 @@
+// Copyright 2018 The gVisor 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 criutil contains utility functions for interacting with the
+// Container Runtime Interface (CRI), principally via the crictl command line
+// tool. This requires critools to be installed on the local system.
+package criutil
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"gvisor.dev/gvisor/pkg/test/dockerutil"
+	"gvisor.dev/gvisor/pkg/test/testutil"
+)
+
+// Crictl contains information required to run the crictl utility.
+type Crictl struct {
+	logger   testutil.Logger
+	endpoint string
+	cleanup  []func()
+}
+
+// resolvePath attempts to find binary paths. It may set the path to invalid,
+// which will cause the execution to fail with a sensible error.
+func resolvePath(executable string) string {
+	guess, err := exec.LookPath(executable)
+	if err != nil {
+		guess = fmt.Sprintf("/usr/local/bin/%s", executable)
+	}
+	return guess
+}
+
+// NewCrictl returns a Crictl configured with a timeout and an endpoint over
+// which it will talk to containerd.
+func NewCrictl(logger testutil.Logger, endpoint string) *Crictl {
+	// Attempt to find the executable, but don't bother propagating the
+	// error at this point. The first command executed will return with a
+	// binary not found error.
+	return &Crictl{
+		logger:   logger,
+		endpoint: endpoint,
+	}
+}
+
+// CleanUp executes cleanup functions.
+func (cc *Crictl) CleanUp() {
+	for _, c := range cc.cleanup {
+		c()
+	}
+	cc.cleanup = nil
+}
+
+// RunPod creates a sandbox. It corresponds to `crictl runp`.
+func (cc *Crictl) RunPod(sbSpecFile string) (string, error) {
+	podID, err := cc.run("runp", sbSpecFile)
+	if err != nil {
+		return "", fmt.Errorf("runp failed: %v", err)
+	}
+	// Strip the trailing newline from crictl output.
+	return strings.TrimSpace(podID), nil
+}
+
+// Create creates a container within a sandbox. It corresponds to `crictl
+// create`.
+func (cc *Crictl) Create(podID, contSpecFile, sbSpecFile string) (string, error) {
+	podID, err := cc.run("create", podID, contSpecFile, sbSpecFile)
+	if err != nil {
+		return "", fmt.Errorf("create failed: %v", err)
+	}
+	// Strip the trailing newline from crictl output.
+	return strings.TrimSpace(podID), nil
+}
+
+// Start starts a container. It corresponds to `crictl start`.
+func (cc *Crictl) Start(contID string) (string, error) {
+	output, err := cc.run("start", contID)
+	if err != nil {
+		return "", fmt.Errorf("start failed: %v", err)
+	}
+	return output, nil
+}
+
+// Stop stops a container. It corresponds to `crictl stop`.
+func (cc *Crictl) Stop(contID string) error {
+	_, err := cc.run("stop", contID)
+	return err
+}
+
+// Exec execs a program inside a container. It corresponds to `crictl exec`.
+func (cc *Crictl) Exec(contID string, args ...string) (string, error) {
+	a := []string{"exec", contID}
+	a = append(a, args...)
+	output, err := cc.run(a...)
+	if err != nil {
+		return "", fmt.Errorf("exec failed: %v", err)
+	}
+	return output, nil
+}
+
+// Rm removes a container. It corresponds to `crictl rm`.
+func (cc *Crictl) Rm(contID string) error {
+	_, err := cc.run("rm", contID)
+	return err
+}
+
+// StopPod stops a pod. It corresponds to `crictl stopp`.
+func (cc *Crictl) StopPod(podID string) error {
+	_, err := cc.run("stopp", podID)
+	return err
+}
+
+// containsConfig is a minimal copy of
+// https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/apis/cri/runtime/v1alpha2/api.proto
+// It only contains fields needed for testing.
+type containerConfig struct {
+	Status containerStatus
+}
+
+type containerStatus struct {
+	Network containerNetwork
+}
+
+type containerNetwork struct {
+	IP string
+}
+
+// PodIP returns a pod's IP address.
+func (cc *Crictl) PodIP(podID string) (string, error) {
+	output, err := cc.run("inspectp", podID)
+	if err != nil {
+		return "", err
+	}
+	conf := &containerConfig{}
+	if err := json.Unmarshal([]byte(output), conf); err != nil {
+		return "", fmt.Errorf("failed to unmarshal JSON: %v, %s", err, output)
+	}
+	if conf.Status.Network.IP == "" {
+		return "", fmt.Errorf("no IP found in config: %s", output)
+	}
+	return conf.Status.Network.IP, nil
+}
+
+// RmPod removes a container. It corresponds to `crictl rmp`.
+func (cc *Crictl) RmPod(podID string) error {
+	_, err := cc.run("rmp", podID)
+	return err
+}
+
+// Import imports the given container from the local Docker instance.
+func (cc *Crictl) Import(image string) error {
+	// Note that we provide a 10 minute timeout after connect because we may
+	// be pushing a lot of bytes in order to import the image. The connect
+	// timeout stays the same and is inherited from the Crictl instance.
+	cmd := testutil.Command(cc.logger,
+		resolvePath("ctr"),
+		fmt.Sprintf("--connect-timeout=%s", 30*time.Second),
+		fmt.Sprintf("--address=%s", cc.endpoint),
+		"-n", "k8s.io", "images", "import", "-")
+	cmd.Stderr = os.Stderr // Pass through errors.
+
+	// Create a pipe and start the program.
+	w, err := cmd.StdinPipe()
+	if err != nil {
+		return err
+	}
+	if err := cmd.Start(); err != nil {
+		return err
+	}
+
+	// Save the image on the other end.
+	if err := dockerutil.Save(cc.logger, image, w); err != nil {
+		cmd.Wait()
+		return err
+	}
+
+	// Close our pipe reference & see if it was loaded.
+	if err := w.Close(); err != nil {
+		return w.Close()
+	}
+
+	return cmd.Wait()
+}
+
+// StartContainer pulls the given image ands starts the container in the
+// sandbox with the given podID.
+//
+// Note that the image will always be imported from the local docker daemon.
+func (cc *Crictl) StartContainer(podID, image, sbSpec, contSpec string) (string, error) {
+	if err := cc.Import(image); err != nil {
+		return "", err
+	}
+
+	// Write the specs to files that can be read by crictl.
+	sbSpecFile, cleanup, err := testutil.WriteTmpFile("sbSpec", sbSpec)
+	if err != nil {
+		return "", fmt.Errorf("failed to write sandbox spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+	contSpecFile, cleanup, err := testutil.WriteTmpFile("contSpec", contSpec)
+	if err != nil {
+		return "", fmt.Errorf("failed to write container spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+
+	return cc.startContainer(podID, image, sbSpecFile, contSpecFile)
+}
+
+func (cc *Crictl) startContainer(podID, image, sbSpecFile, contSpecFile string) (string, error) {
+	contID, err := cc.Create(podID, contSpecFile, sbSpecFile)
+	if err != nil {
+		return "", fmt.Errorf("failed to create container in pod %q: %v", podID, err)
+	}
+
+	if _, err := cc.Start(contID); err != nil {
+		return "", fmt.Errorf("failed to start container %q in pod %q: %v", contID, podID, err)
+	}
+
+	return contID, nil
+}
+
+// StopContainer stops and deletes the container with the given container ID.
+func (cc *Crictl) StopContainer(contID string) error {
+	if err := cc.Stop(contID); err != nil {
+		return fmt.Errorf("failed to stop container %q: %v", contID, err)
+	}
+
+	if err := cc.Rm(contID); err != nil {
+		return fmt.Errorf("failed to remove container %q: %v", contID, err)
+	}
+
+	return nil
+}
+
+// StartPodAndContainer starts a sandbox and container in that sandbox. It
+// returns the pod ID and container ID.
+func (cc *Crictl) StartPodAndContainer(image, sbSpec, contSpec string) (string, string, error) {
+	if err := cc.Import(image); err != nil {
+		return "", "", err
+	}
+
+	// Write the specs to files that can be read by crictl.
+	sbSpecFile, cleanup, err := testutil.WriteTmpFile("sbSpec", sbSpec)
+	if err != nil {
+		return "", "", fmt.Errorf("failed to write sandbox spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+	contSpecFile, cleanup, err := testutil.WriteTmpFile("contSpec", contSpec)
+	if err != nil {
+		return "", "", fmt.Errorf("failed to write container spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+
+	podID, err := cc.RunPod(sbSpecFile)
+	if err != nil {
+		return "", "", err
+	}
+
+	contID, err := cc.startContainer(podID, image, sbSpecFile, contSpecFile)
+
+	return podID, contID, err
+}
+
+// StopPodAndContainer stops a container and pod.
+func (cc *Crictl) StopPodAndContainer(podID, contID string) error {
+	if err := cc.StopContainer(contID); err != nil {
+		return fmt.Errorf("failed to stop container %q in pod %q: %v", contID, podID, err)
+	}
+
+	if err := cc.StopPod(podID); err != nil {
+		return fmt.Errorf("failed to stop pod %q: %v", podID, err)
+	}
+
+	if err := cc.RmPod(podID); err != nil {
+		return fmt.Errorf("failed to remove pod %q: %v", podID, err)
+	}
+
+	return nil
+}
+
+// run runs crictl with the given args.
+func (cc *Crictl) run(args ...string) (string, error) {
+	defaultArgs := []string{
+		resolvePath("crictl"),
+		"--image-endpoint", fmt.Sprintf("unix://%s", cc.endpoint),
+		"--runtime-endpoint", fmt.Sprintf("unix://%s", cc.endpoint),
+	}
+	fullArgs := append(defaultArgs, args...)
+	out, err := testutil.Command(cc.logger, fullArgs...).CombinedOutput()
+	return string(out), err
+}
diff --git a/pkg/test/dockerutil/BUILD b/pkg/test/dockerutil/BUILD
new file mode 100644
index 000000000..7c8758e35
--- /dev/null
+++ b/pkg/test/dockerutil/BUILD
@@ -0,0 +1,14 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "dockerutil",
+    testonly = 1,
+    srcs = ["dockerutil.go"],
+    visibility = ["//:sandbox"],
+    deps = [
+        "//pkg/test/testutil",
+        "@com_github_kr_pty//:go_default_library",
+    ],
+)
diff --git a/pkg/test/dockerutil/dockerutil.go b/pkg/test/dockerutil/dockerutil.go
new file mode 100644
index 000000000..baa8fc2f2
--- /dev/null
+++ b/pkg/test/dockerutil/dockerutil.go
@@ -0,0 +1,581 @@
+// Copyright 2018 The gVisor 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 dockerutil is a collection of utility functions.
+package dockerutil
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"os/exec"
+	"path"
+	"regexp"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/kr/pty"
+	"gvisor.dev/gvisor/pkg/test/testutil"
+)
+
+var (
+	// runtime is the runtime to use for tests. This will be applied to all
+	// containers. Note that the default here ("runsc") corresponds to the
+	// default used by the installations. This is important, because the
+	// default installer for vm_tests (in tools/installers:head, invoked
+	// via tools/vm:defs.bzl) will install with this name. So without
+	// changing anything, tests should have a runsc runtime available to
+	// them. Otherwise installers should update the existing runtime
+	// instead of installing a new one.
+	runtime = flag.String("runtime", "runsc", "specify which runtime to use")
+
+	// config is the default Docker daemon configuration path.
+	config = flag.String("config_path", "/etc/docker/daemon.json", "configuration file for reading paths")
+)
+
+// EnsureSupportedDockerVersion checks if correct docker is installed.
+//
+// This logs directly to stderr, as it is typically called from a Main wrapper.
+func EnsureSupportedDockerVersion() {
+	cmd := exec.Command("docker", "version")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Fatalf("error running %q: %v", "docker version", err)
+	}
+	re := regexp.MustCompile(`Version:\s+(\d+)\.(\d+)\.\d.*`)
+	matches := re.FindStringSubmatch(string(out))
+	if len(matches) != 3 {
+		log.Fatalf("Invalid docker output: %s", out)
+	}
+	major, _ := strconv.Atoi(matches[1])
+	minor, _ := strconv.Atoi(matches[2])
+	if major < 17 || (major == 17 && minor < 9) {
+		log.Fatalf("Docker version 17.09.0 or greater is required, found: %02d.%02d", major, minor)
+	}
+}
+
+// RuntimePath returns the binary path for the current runtime.
+func RuntimePath() (string, error) {
+	// Read the configuration data; the file must exist.
+	configBytes, err := ioutil.ReadFile(*config)
+	if err != nil {
+		return "", err
+	}
+
+	// Unmarshal the configuration.
+	c := make(map[string]interface{})
+	if err := json.Unmarshal(configBytes, &c); err != nil {
+		return "", err
+	}
+
+	// Decode the expected configuration.
+	r, ok := c["runtimes"]
+	if !ok {
+		return "", fmt.Errorf("no runtimes declared: %v", c)
+	}
+	rs, ok := r.(map[string]interface{})
+	if !ok {
+		// The runtimes are not a map.
+		return "", fmt.Errorf("unexpected format: %v", c)
+	}
+	r, ok = rs[*runtime]
+	if !ok {
+		// The expected runtime is not declared.
+		return "", fmt.Errorf("runtime %q not found: %v", *runtime, c)
+	}
+	rs, ok = r.(map[string]interface{})
+	if !ok {
+		// The runtime is not a map.
+		return "", fmt.Errorf("unexpected format: %v", c)
+	}
+	p, ok := rs["path"].(string)
+	if !ok {
+		// The runtime does not declare a path.
+		return "", fmt.Errorf("unexpected format: %v", c)
+	}
+	return p, nil
+}
+
+// Save exports a container image to the given Writer.
+//
+// Note that the writer should be actively consuming the output, otherwise it
+// is not guaranteed that the Save will make any progress and the call may
+// stall indefinitely.
+//
+// This is called by criutil in order to import imports.
+func Save(logger testutil.Logger, image string, w io.Writer) error {
+	cmd := testutil.Command(logger, "docker", "save", testutil.ImageByName(image))
+	cmd.Stdout = w // Send directly to the writer.
+	return cmd.Run()
+}
+
+// MountMode describes if the mount should be ro or rw.
+type MountMode int
+
+const (
+	// ReadOnly is what the name says.
+	ReadOnly MountMode = iota
+	// ReadWrite is what the name says.
+	ReadWrite
+)
+
+// String returns the mount mode argument for this MountMode.
+func (m MountMode) String() string {
+	switch m {
+	case ReadOnly:
+		return "ro"
+	case ReadWrite:
+		return "rw"
+	}
+	panic(fmt.Sprintf("invalid mode: %d", m))
+}
+
+// Docker contains the name and the runtime of a docker container.
+type Docker struct {
+	logger   testutil.Logger
+	Runtime  string
+	Name     string
+	copyErr  error
+	mounts   []string
+	cleanups []func()
+}
+
+// MakeDocker sets up the struct for a Docker container.
+//
+// Names of containers will be unique.
+func MakeDocker(logger testutil.Logger) *Docker {
+	return &Docker{
+		logger:  logger,
+		Name:    testutil.RandomID(logger.Name()),
+		Runtime: *runtime,
+	}
+}
+
+// Mount mounts the given source and makes it available in the container.
+func (d *Docker) Mount(target, source string, mode MountMode) {
+	d.mounts = append(d.mounts, fmt.Sprintf("-v=%s:%s:%v", source, target, mode))
+}
+
+// CopyFiles copies in and mounts the given files. They are always ReadOnly.
+func (d *Docker) CopyFiles(target string, sources ...string) {
+	dir, err := ioutil.TempDir("", d.Name)
+	if err != nil {
+		d.copyErr = fmt.Errorf("ioutil.TempDir failed: %v", err)
+		return
+	}
+	d.cleanups = append(d.cleanups, func() { os.RemoveAll(dir) })
+	if err := os.Chmod(dir, 0755); err != nil {
+		d.copyErr = fmt.Errorf("os.Chmod(%q, 0755) failed: %v", dir, err)
+		return
+	}
+	for _, name := range sources {
+		src, err := testutil.FindFile(name)
+		if err != nil {
+			d.copyErr = fmt.Errorf("testutil.FindFile(%q) failed: %v", name, err)
+			return
+		}
+		dst := path.Join(dir, path.Base(name))
+		if err := testutil.Copy(src, dst); err != nil {
+			d.copyErr = fmt.Errorf("testutil.Copy(%q, %q) failed: %v", src, dst, err)
+			return
+		}
+		d.logger.Logf("copy: %s -> %s", src, dst)
+	}
+	d.Mount(target, dir, ReadOnly)
+}
+
+// Link links the given target.
+func (d *Docker) Link(target string, source *Docker) {
+	d.mounts = append(d.mounts, fmt.Sprintf("--link=%s:%s", source.Name, target))
+}
+
+// RunOpts are options for running a container.
+type RunOpts struct {
+	// Image is the image relative to images/. This will be mangled
+	// appropriately, to ensure that only first-party images are used.
+	Image string
+
+	// Memory is the memory limit in kB.
+	Memory int
+
+	// Ports are the ports to be allocated.
+	Ports []int
+
+	// WorkDir sets the working directory.
+	WorkDir string
+
+	// ReadOnly sets the read-only flag.
+	ReadOnly bool
+
+	// Env are additional environment variables.
+	Env []string
+
+	// User is the user to use.
+	User string
+
+	// Privileged enables privileged mode.
+	Privileged bool
+
+	// CapAdd are the extra set of capabilities to add.
+	CapAdd []string
+
+	// CapDrop are the extra set of capabilities to drop.
+	CapDrop []string
+
+	// Pty indicates that a pty will be allocated. If this is non-nil, then
+	// this will run after start-up with the *exec.Command and Pty file
+	// passed in to the function.
+	Pty func(*exec.Cmd, *os.File)
+
+	// Foreground indicates that the container should be run in the
+	// foreground. If this is true, then the output will be available as a
+	// return value from the Run function.
+	Foreground bool
+
+	// Extra are extra arguments that may be passed.
+	Extra []string
+}
+
+// args returns common arguments.
+//
+// Note that this does not define the complete behavior.
+func (d *Docker) argsFor(r *RunOpts, command string, p []string) (rv []string) {
+	isExec := command == "exec"
+	isRun := command == "run"
+
+	if isRun || isExec {
+		rv = append(rv, "-i")
+	}
+	if r.Pty != nil {
+		rv = append(rv, "-t")
+	}
+	if r.User != "" {
+		rv = append(rv, fmt.Sprintf("--user=%s", r.User))
+	}
+	if r.Privileged {
+		rv = append(rv, "--privileged")
+	}
+	for _, c := range r.CapAdd {
+		rv = append(rv, fmt.Sprintf("--cap-add=%s", c))
+	}
+	for _, c := range r.CapDrop {
+		rv = append(rv, fmt.Sprintf("--cap-drop=%s", c))
+	}
+	for _, e := range r.Env {
+		rv = append(rv, fmt.Sprintf("--env=%s", e))
+	}
+	if r.WorkDir != "" {
+		rv = append(rv, fmt.Sprintf("--workdir=%s", r.WorkDir))
+	}
+	if !isExec {
+		if r.Memory != 0 {
+			rv = append(rv, fmt.Sprintf("--memory=%dk", r.Memory))
+		}
+		for _, p := range r.Ports {
+			rv = append(rv, fmt.Sprintf("--publish=%d", p))
+		}
+		if r.ReadOnly {
+			rv = append(rv, fmt.Sprintf("--read-only"))
+		}
+		if len(p) > 0 {
+			rv = append(rv, "--entrypoint=")
+		}
+	}
+
+	// Always attach the test environment & Extra.
+	rv = append(rv, fmt.Sprintf("--env=RUNSC_TEST_NAME=%s", d.Name))
+	rv = append(rv, r.Extra...)
+
+	// Attach necessary bits.
+	if isExec {
+		rv = append(rv, d.Name)
+	} else {
+		rv = append(rv, d.mounts...)
+		rv = append(rv, fmt.Sprintf("--runtime=%s", d.Runtime))
+		rv = append(rv, fmt.Sprintf("--name=%s", d.Name))
+		rv = append(rv, testutil.ImageByName(r.Image))
+	}
+
+	// Attach other arguments.
+	rv = append(rv, p...)
+	return rv
+}
+
+// run runs a complete command.
+func (d *Docker) run(r RunOpts, command string, p ...string) (string, error) {
+	if d.copyErr != nil {
+		return "", d.copyErr
+	}
+	basicArgs := []string{"docker"}
+	if command == "spawn" {
+		command = "run"
+		basicArgs = append(basicArgs, command)
+		basicArgs = append(basicArgs, "-d")
+	} else {
+		basicArgs = append(basicArgs, command)
+	}
+	customArgs := d.argsFor(&r, command, p)
+	cmd := testutil.Command(d.logger, append(basicArgs, customArgs...)...)
+	if r.Pty != nil {
+		// If allocating a terminal, then we just ignore the output
+		// from the command.
+		ptmx, err := pty.Start(cmd.Cmd)
+		if err != nil {
+			return "", err
+		}
+		defer cmd.Wait() // Best effort.
+		r.Pty(cmd.Cmd, ptmx)
+	} else {
+		// Can't support PTY or streaming.
+		out, err := cmd.CombinedOutput()
+		return string(out), err
+	}
+	return "", nil
+}
+
+// Create calls 'docker create' with the arguments provided.
+func (d *Docker) Create(r RunOpts, args ...string) error {
+	_, err := d.run(r, "create", args...)
+	return err
+}
+
+// Start calls 'docker start'.
+func (d *Docker) Start() error {
+	return testutil.Command(d.logger, "docker", "start", d.Name).Run()
+}
+
+// Stop calls 'docker stop'.
+func (d *Docker) Stop() error {
+	return testutil.Command(d.logger, "docker", "stop", d.Name).Run()
+}
+
+// Run calls 'docker run' with the arguments provided.
+func (d *Docker) Run(r RunOpts, args ...string) (string, error) {
+	return d.run(r, "run", args...)
+}
+
+// Spawn starts the container and detaches.
+func (d *Docker) Spawn(r RunOpts, args ...string) error {
+	_, err := d.run(r, "spawn", args...)
+	return err
+}
+
+// Logs calls 'docker logs'.
+func (d *Docker) Logs() (string, error) {
+	// Don't capture the output; since it will swamp the logs.
+	out, err := exec.Command("docker", "logs", d.Name).CombinedOutput()
+	return string(out), err
+}
+
+// Exec calls 'docker exec' with the arguments provided.
+func (d *Docker) Exec(r RunOpts, args ...string) (string, error) {
+	return d.run(r, "exec", args...)
+}
+
+// Pause calls 'docker pause'.
+func (d *Docker) Pause() error {
+	return testutil.Command(d.logger, "docker", "pause", d.Name).Run()
+}
+
+// Unpause calls 'docker pause'.
+func (d *Docker) Unpause() error {
+	return testutil.Command(d.logger, "docker", "unpause", d.Name).Run()
+}
+
+// Checkpoint calls 'docker checkpoint'.
+func (d *Docker) Checkpoint(name string) error {
+	return testutil.Command(d.logger, "docker", "checkpoint", "create", d.Name, name).Run()
+}
+
+// Restore calls 'docker start --checkname [name]'.
+func (d *Docker) Restore(name string) error {
+	return testutil.Command(d.logger, "docker", "start", fmt.Sprintf("--checkpoint=%s", name), d.Name).Run()
+}
+
+// Kill calls 'docker kill'.
+func (d *Docker) Kill() error {
+	// Skip logging this command, it will likely be an error.
+	out, err := exec.Command("docker", "kill", d.Name).CombinedOutput()
+	if err != nil && !strings.Contains(string(out), "is not running") {
+		return err
+	}
+	return nil
+}
+
+// Remove calls 'docker rm'.
+func (d *Docker) Remove() error {
+	return testutil.Command(d.logger, "docker", "rm", d.Name).Run()
+}
+
+// CleanUp kills and deletes the container (best effort).
+func (d *Docker) CleanUp() {
+	// Kill the container.
+	if err := d.Kill(); err != nil {
+		// Just log; can't do anything here.
+		d.logger.Logf("error killing container %q: %v", d.Name, err)
+	}
+	// Remove the image.
+	if err := d.Remove(); err != nil {
+		d.logger.Logf("error removing container %q: %v", d.Name, err)
+	}
+	// Forget all mounts.
+	d.mounts = nil
+	// Execute all cleanups.
+	for _, c := range d.cleanups {
+		c()
+	}
+	d.cleanups = nil
+}
+
+// FindPort returns the host port that is mapped to 'sandboxPort'. This calls
+// docker to allocate a free port in the host and prevent conflicts.
+func (d *Docker) FindPort(sandboxPort int) (int, error) {
+	format := fmt.Sprintf(`{{ (index (index .NetworkSettings.Ports "%d/tcp") 0).HostPort }}`, sandboxPort)
+	out, err := testutil.Command(d.logger, "docker", "inspect", "-f", format, d.Name).CombinedOutput()
+	if err != nil {
+		return -1, fmt.Errorf("error retrieving port: %v", err)
+	}
+	port, err := strconv.Atoi(strings.TrimSuffix(string(out), "\n"))
+	if err != nil {
+		return -1, fmt.Errorf("error parsing port %q: %v", out, err)
+	}
+	return port, nil
+}
+
+// FindIP returns the IP address of the container.
+func (d *Docker) FindIP() (net.IP, error) {
+	const format = `{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}`
+	out, err := testutil.Command(d.logger, "docker", "inspect", "-f", format, d.Name).CombinedOutput()
+	if err != nil {
+		return net.IP{}, fmt.Errorf("error retrieving IP: %v", err)
+	}
+	ip := net.ParseIP(strings.TrimSpace(string(out)))
+	if ip == nil {
+		return net.IP{}, fmt.Errorf("invalid IP: %q", string(out))
+	}
+	return ip, nil
+}
+
+// SandboxPid returns the PID to the sandbox process.
+func (d *Docker) SandboxPid() (int, error) {
+	out, err := testutil.Command(d.logger, "docker", "inspect", "-f={{.State.Pid}}", d.Name).CombinedOutput()
+	if err != nil {
+		return -1, fmt.Errorf("error retrieving pid: %v", err)
+	}
+	pid, err := strconv.Atoi(strings.TrimSuffix(string(out), "\n"))
+	if err != nil {
+		return -1, fmt.Errorf("error parsing pid %q: %v", out, err)
+	}
+	return pid, nil
+}
+
+// ID returns the container ID.
+func (d *Docker) ID() (string, error) {
+	out, err := testutil.Command(d.logger, "docker", "inspect", "-f={{.Id}}", d.Name).CombinedOutput()
+	if err != nil {
+		return "", fmt.Errorf("error retrieving ID: %v", err)
+	}
+	return strings.TrimSpace(string(out)), nil
+}
+
+// Wait waits for container to exit, up to the given timeout. Returns error if
+// wait fails or timeout is hit. Returns the application return code otherwise.
+// Note that the application may have failed even if err == nil, always check
+// the exit code.
+func (d *Docker) Wait(timeout time.Duration) (syscall.WaitStatus, error) {
+	timeoutChan := time.After(timeout)
+	waitChan := make(chan (syscall.WaitStatus))
+	errChan := make(chan (error))
+
+	go func() {
+		out, err := testutil.Command(d.logger, "docker", "wait", d.Name).CombinedOutput()
+		if err != nil {
+			errChan <- fmt.Errorf("error waiting for container %q: %v", d.Name, err)
+		}
+		exit, err := strconv.Atoi(strings.TrimSuffix(string(out), "\n"))
+		if err != nil {
+			errChan <- fmt.Errorf("error parsing exit code %q: %v", out, err)
+		}
+		waitChan <- syscall.WaitStatus(uint32(exit))
+	}()
+
+	select {
+	case ws := <-waitChan:
+		return ws, nil
+	case err := <-errChan:
+		return syscall.WaitStatus(1), err
+	case <-timeoutChan:
+		return syscall.WaitStatus(1), fmt.Errorf("timeout waiting for container %q", d.Name)
+	}
+}
+
+// WaitForOutput calls 'docker logs' to retrieve containers output and searches
+// for the given pattern.
+func (d *Docker) WaitForOutput(pattern string, timeout time.Duration) (string, error) {
+	matches, err := d.WaitForOutputSubmatch(pattern, timeout)
+	if err != nil {
+		return "", err
+	}
+	if len(matches) == 0 {
+		return "", nil
+	}
+	return matches[0], nil
+}
+
+// WaitForOutputSubmatch calls 'docker logs' to retrieve containers output and
+// searches for the given pattern. It returns any regexp submatches as well.
+func (d *Docker) WaitForOutputSubmatch(pattern string, timeout time.Duration) ([]string, error) {
+	re := regexp.MustCompile(pattern)
+	var (
+		lastOut string
+		stopped bool
+	)
+	for exp := time.Now().Add(timeout); time.Now().Before(exp); {
+		out, err := d.Logs()
+		if err != nil {
+			return nil, err
+		}
+		if out != lastOut {
+			if lastOut == "" {
+				d.logger.Logf("output (start): %s", out)
+			} else if strings.HasPrefix(out, lastOut) {
+				d.logger.Logf("output (contn): %s", out[len(lastOut):])
+			} else {
+				d.logger.Logf("output (trunc): %s", out)
+			}
+			lastOut = out // Save for future.
+			if matches := re.FindStringSubmatch(lastOut); matches != nil {
+				return matches, nil // Success!
+			}
+		} else if stopped {
+			// The sandbox stopped and we looked at the
+			// logs at least once since determining that.
+			return nil, fmt.Errorf("no longer running: %v", err)
+		} else if pid, err := d.SandboxPid(); pid == 0 || err != nil {
+			// The sandbox may have stopped, but it's
+			// possible that it has emitted the terminal
+			// line between the last call to Logs and here.
+			stopped = true
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+	return nil, fmt.Errorf("timeout waiting for output %q: %s", re.String(), lastOut)
+}
diff --git a/pkg/test/testutil/BUILD b/pkg/test/testutil/BUILD
new file mode 100644
index 000000000..03b1b4677
--- /dev/null
+++ b/pkg/test/testutil/BUILD
@@ -0,0 +1,20 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "testutil",
+    testonly = 1,
+    srcs = [
+        "testutil.go",
+        "testutil_runfiles.go",
+    ],
+    visibility = ["//:sandbox"],
+    deps = [
+        "//pkg/sync",
+        "//runsc/boot",
+        "//runsc/specutils",
+        "@com_github_cenkalti_backoff//:go_default_library",
+        "@com_github_opencontainers_runtime-spec//specs-go:go_default_library",
+    ],
+)
diff --git a/pkg/test/testutil/testutil.go b/pkg/test/testutil/testutil.go
new file mode 100644
index 000000000..d75ceca3d
--- /dev/null
+++ b/pkg/test/testutil/testutil.go
@@ -0,0 +1,550 @@
+// Copyright 2018 The gVisor 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 testutil contains utility functions for runsc tests.
+package testutil
+
+import (
+	"bufio"
+	"context"
+	"debug/elf"
+	"encoding/base32"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"math"
+	"math/rand"
+	"net/http"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/cenkalti/backoff"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"gvisor.dev/gvisor/pkg/sync"
+	"gvisor.dev/gvisor/runsc/boot"
+	"gvisor.dev/gvisor/runsc/specutils"
+)
+
+var (
+	checkpoint = flag.Bool("checkpoint", true, "control checkpoint/restore support")
+)
+
+// IsCheckpointSupported returns the relevant command line flag.
+func IsCheckpointSupported() bool {
+	return *checkpoint
+}
+
+// nameToActual is used by ImageByName (for now).
+var nameToActual = map[string]string{
+	"basic/alpine":          "alpine",
+	"basic/busybox":         "busybox:1.31.1",
+	"basic/httpd":           "httpd",
+	"basic/mysql":           "mysql",
+	"basic/nginx":           "nginx",
+	"basic/python":          "gcr.io/gvisor-presubmit/python-hello",
+	"basic/resolv":          "k8s.gcr.io/busybox",
+	"basic/ruby":            "ruby",
+	"basic/tomcat":          "tomcat:8.0",
+	"basic/ubuntu":          "ubuntu:trusty",
+	"iptables":              "gcr.io/gvisor-presubmit/iptables-test",
+	"packetdrill":           "gcr.io/gvisor-presubmit/packetdrill",
+	"packetimpact":          "gcr.io/gvisor-presubmit/packetimpact",
+	"runtimes/go1.12":       "gcr.io/gvisor-presubmit/go1.12",
+	"runtimes/java11":       "gcr.io/gvisor-presubmit/java11",
+	"runtimes/nodejs12.4.0": "gcr.io/gvisor-presubmit/nodejs12.4.0",
+	"runtimes/php7.3.6":     "gcr.io/gvisor-presubmit/php7.3.6",
+	"runtimes/python3.7.3":  "gcr.io/gvisor-presubmit/python3.7.3",
+}
+
+// ImageByName mangles the image name used locally.
+//
+// For now, this is implemented as a static lookup table. In a subsequent
+// change, this will be used to reference a locally-generated image.
+func ImageByName(name string) string {
+	actual, ok := nameToActual[name]
+	if !ok {
+		panic(fmt.Sprintf("unknown image: %v", name))
+	}
+	// A terrible hack, for now execute a manual pull.
+	if out, err := exec.Command("docker", "pull", actual).CombinedOutput(); err != nil {
+		panic(fmt.Sprintf("error pulling image %q -> %q: %v, out: %s", name, actual, err, string(out)))
+	}
+	return actual
+}
+
+// ConfigureExePath configures the executable for runsc in the test environment.
+func ConfigureExePath() error {
+	path, err := FindFile("runsc/runsc")
+	if err != nil {
+		return err
+	}
+	specutils.ExePath = path
+	return nil
+}
+
+// TmpDir returns the absolute path to a writable directory that can be used as
+// scratch by the test.
+func TmpDir() string {
+	dir := os.Getenv("TEST_TMPDIR")
+	if dir == "" {
+		dir = "/tmp"
+	}
+	return dir
+}
+
+// Logger is a simple logging wrapper.
+//
+// This is designed to be implemented by *testing.T.
+type Logger interface {
+	Name() string
+	Logf(fmt string, args ...interface{})
+}
+
+// DefaultLogger logs using the log package.
+type DefaultLogger string
+
+// Name implements Logger.Name.
+func (d DefaultLogger) Name() string {
+	return string(d)
+}
+
+// Logf implements Logger.Logf.
+func (d DefaultLogger) Logf(fmt string, args ...interface{}) {
+	log.Printf(fmt, args...)
+}
+
+// Cmd is a simple wrapper.
+type Cmd struct {
+	logger Logger
+	*exec.Cmd
+}
+
+// CombinedOutput returns the output and logs.
+func (c *Cmd) CombinedOutput() ([]byte, error) {
+	out, err := c.Cmd.CombinedOutput()
+	if len(out) > 0 {
+		c.logger.Logf("output: %s", string(out))
+	}
+	if err != nil {
+		c.logger.Logf("error: %v", err)
+	}
+	return out, err
+}
+
+// Command is a simple wrapper around exec.Command, that logs.
+func Command(logger Logger, args ...string) *Cmd {
+	logger.Logf("command: %s", strings.Join(args, " "))
+	return &Cmd{
+		logger: logger,
+		Cmd:    exec.Command(args[0], args[1:]...),
+	}
+}
+
+// TestConfig returns the default configuration to use in tests. Note that
+// 'RootDir' must be set by caller if required.
+func TestConfig(t *testing.T) *boot.Config {
+	logDir := os.TempDir()
+	if dir, ok := os.LookupEnv("TEST_UNDECLARED_OUTPUTS_DIR"); ok {
+		logDir = dir + "/"
+	}
+	return &boot.Config{
+		Debug:              true,
+		DebugLog:           path.Join(logDir, "runsc.log."+t.Name()+".%TIMESTAMP%.%COMMAND%"),
+		LogFormat:          "text",
+		DebugLogFormat:     "text",
+		LogPackets:         true,
+		Network:            boot.NetworkNone,
+		Strace:             true,
+		Platform:           "ptrace",
+		FileAccess:         boot.FileAccessExclusive,
+		NumNetworkChannels: 1,
+
+		TestOnlyAllowRunAsCurrentUserWithoutChroot: true,
+	}
+}
+
+// NewSpecWithArgs creates a simple spec with the given args suitable for use
+// in tests.
+func NewSpecWithArgs(args ...string) *specs.Spec {
+	return &specs.Spec{
+		// The host filesystem root is the container root.
+		Root: &specs.Root{
+			Path:     "/",
+			Readonly: true,
+		},
+		Process: &specs.Process{
+			Args: args,
+			Env: []string{
+				"PATH=" + os.Getenv("PATH"),
+			},
+			Capabilities: specutils.AllCapabilities(),
+		},
+		Mounts: []specs.Mount{
+			// Hide the host /etc to avoid any side-effects.
+			// For example, bash reads /etc/passwd and if it is
+			// very big, tests can fail by timeout.
+			{
+				Type:        "tmpfs",
+				Destination: "/etc",
+			},
+			// Root is readonly, but many tests want to write to tmpdir.
+			// This creates a writable mount inside the root. Also, when tmpdir points
+			// to "/tmp", it makes the the actual /tmp to be mounted and not a tmpfs
+			// inside the sentry.
+			{
+				Type:        "bind",
+				Destination: TmpDir(),
+				Source:      TmpDir(),
+			},
+		},
+		Hostname: "runsc-test-hostname",
+	}
+}
+
+// SetupRootDir creates a root directory for containers.
+func SetupRootDir() (string, func(), error) {
+	rootDir, err := ioutil.TempDir(TmpDir(), "containers")
+	if err != nil {
+		return "", nil, fmt.Errorf("error creating root dir: %v", err)
+	}
+	return rootDir, func() { os.RemoveAll(rootDir) }, nil
+}
+
+// SetupContainer creates a bundle and root dir for the container, generates a
+// test config, and writes the spec to config.json in the bundle dir.
+func SetupContainer(spec *specs.Spec, conf *boot.Config) (rootDir, bundleDir string, cleanup func(), err error) {
+	rootDir, rootCleanup, err := SetupRootDir()
+	if err != nil {
+		return "", "", nil, err
+	}
+	conf.RootDir = rootDir
+	bundleDir, bundleCleanup, err := SetupBundleDir(spec)
+	if err != nil {
+		rootCleanup()
+		return "", "", nil, err
+	}
+	return rootDir, bundleDir, func() {
+		bundleCleanup()
+		rootCleanup()
+	}, err
+}
+
+// SetupBundleDir creates a bundle dir and writes the spec to config.json.
+func SetupBundleDir(spec *specs.Spec) (string, func(), error) {
+	bundleDir, err := ioutil.TempDir(TmpDir(), "bundle")
+	if err != nil {
+		return "", nil, fmt.Errorf("error creating bundle dir: %v", err)
+	}
+	cleanup := func() { os.RemoveAll(bundleDir) }
+	if err := writeSpec(bundleDir, spec); err != nil {
+		cleanup()
+		return "", nil, fmt.Errorf("error writing spec: %v", err)
+	}
+	return bundleDir, cleanup, nil
+}
+
+// writeSpec writes the spec to disk in the given directory.
+func writeSpec(dir string, spec *specs.Spec) error {
+	b, err := json.Marshal(spec)
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(filepath.Join(dir, "config.json"), b, 0755)
+}
+
+// RandomID returns 20 random bytes following the given prefix.
+func RandomID(prefix string) string {
+	// Read 20 random bytes.
+	b := make([]byte, 20)
+	// "[Read] always returns len(p) and a nil error." --godoc
+	if _, err := rand.Read(b); err != nil {
+		panic("rand.Read failed: " + err.Error())
+	}
+	return fmt.Sprintf("%s-%s", prefix, base32.StdEncoding.EncodeToString(b))
+}
+
+// RandomContainerID generates a random container id for each test.
+//
+// The container id is used to create an abstract unix domain socket, which
+// must be unique. While the container forbids creating two containers with the
+// same name, sometimes between test runs the socket does not get cleaned up
+// quickly enough, causing container creation to fail.
+func RandomContainerID() string {
+	return RandomID("test-container-")
+}
+
+// Copy copies file from src to dst.
+func Copy(src, dst string) error {
+	in, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+
+	st, err := in.Stat()
+	if err != nil {
+		return err
+	}
+
+	out, err := os.OpenFile(dst, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, st.Mode().Perm())
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	// Mirror the local user's permissions across all users. This is
+	// because as we inject things into the container, the UID/GID will
+	// change. Also, the build system may generate artifacts with different
+	// modes. At the top-level (volume mapping) we have a big read-only
+	// knob that can be applied to prevent modifications.
+	//
+	// Note that this must be done via a separate Chmod call, otherwise the
+	// current process's umask will get in the way.
+	var mode os.FileMode
+	if st.Mode()&0100 != 0 {
+		mode |= 0111
+	}
+	if st.Mode()&0200 != 0 {
+		mode |= 0222
+	}
+	if st.Mode()&0400 != 0 {
+		mode |= 0444
+	}
+	if err := os.Chmod(dst, mode); err != nil {
+		return err
+	}
+
+	_, err = io.Copy(out, in)
+	return err
+}
+
+// Poll is a shorthand function to poll for something with given timeout.
+func Poll(cb func() error, timeout time.Duration) error {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	b := backoff.WithContext(backoff.NewConstantBackOff(100*time.Millisecond), ctx)
+	return backoff.Retry(cb, b)
+}
+
+// WaitForHTTP tries GET requests on a port until the call succeeds or timeout.
+func WaitForHTTP(port int, timeout time.Duration) error {
+	cb := func() error {
+		c := &http.Client{
+			// Calculate timeout to be able to do minimum 5 attempts.
+			Timeout: timeout / 5,
+		}
+		url := fmt.Sprintf("http://localhost:%d/", port)
+		resp, err := c.Get(url)
+		if err != nil {
+			log.Printf("Waiting %s: %v", url, err)
+			return err
+		}
+		resp.Body.Close()
+		return nil
+	}
+	return Poll(cb, timeout)
+}
+
+// Reaper reaps child processes.
+type Reaper struct {
+	// mu protects ch, which will be nil if the reaper is not running.
+	mu sync.Mutex
+	ch chan os.Signal
+}
+
+// Start starts reaping child processes.
+func (r *Reaper) Start() {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if r.ch != nil {
+		panic("reaper.Start called on a running reaper")
+	}
+
+	r.ch = make(chan os.Signal, 1)
+	signal.Notify(r.ch, syscall.SIGCHLD)
+
+	go func() {
+		for {
+			r.mu.Lock()
+			ch := r.ch
+			r.mu.Unlock()
+			if ch == nil {
+				return
+			}
+
+			_, ok := <-ch
+			if !ok {
+				// Channel closed.
+				return
+			}
+			for {
+				cpid, _ := syscall.Wait4(-1, nil, syscall.WNOHANG, nil)
+				if cpid < 1 {
+					break
+				}
+			}
+		}
+	}()
+}
+
+// Stop stops reaping child processes.
+func (r *Reaper) Stop() {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if r.ch == nil {
+		panic("reaper.Stop called on a stopped reaper")
+	}
+
+	signal.Stop(r.ch)
+	close(r.ch)
+	r.ch = nil
+}
+
+// StartReaper is a helper that starts a new Reaper and returns a function to
+// stop it.
+func StartReaper() func() {
+	r := &Reaper{}
+	r.Start()
+	return r.Stop
+}
+
+// WaitUntilRead reads from the given reader until the wanted string is found
+// or until timeout.
+func WaitUntilRead(r io.Reader, want string, split bufio.SplitFunc, timeout time.Duration) error {
+	sc := bufio.NewScanner(r)
+	if split != nil {
+		sc.Split(split)
+	}
+	// done must be accessed atomically. A value greater than 0 indicates
+	// that the read loop can exit.
+	var done uint32
+	doneCh := make(chan struct{})
+	go func() {
+		for sc.Scan() {
+			t := sc.Text()
+			if strings.Contains(t, want) {
+				atomic.StoreUint32(&done, 1)
+				close(doneCh)
+				break
+			}
+			if atomic.LoadUint32(&done) > 0 {
+				break
+			}
+		}
+	}()
+	select {
+	case <-time.After(timeout):
+		atomic.StoreUint32(&done, 1)
+		return fmt.Errorf("timeout waiting to read %q", want)
+	case <-doneCh:
+		return nil
+	}
+}
+
+// KillCommand kills the process running cmd unless it hasn't been started. It
+// returns an error if it cannot kill the process unless the reason is that the
+// process has already exited.
+//
+// KillCommand will also reap the process.
+func KillCommand(cmd *exec.Cmd) error {
+	if cmd.Process == nil {
+		return nil
+	}
+	if err := cmd.Process.Kill(); err != nil {
+		if !strings.Contains(err.Error(), "process already finished") {
+			return fmt.Errorf("failed to kill process %v: %v", cmd, err)
+		}
+	}
+	return cmd.Wait()
+}
+
+// WriteTmpFile writes text to a temporary file, closes the file, and returns
+// the name of the file. A cleanup function is also returned.
+func WriteTmpFile(pattern, text string) (string, func(), error) {
+	file, err := ioutil.TempFile(TmpDir(), pattern)
+	if err != nil {
+		return "", nil, err
+	}
+	defer file.Close()
+	if _, err := file.Write([]byte(text)); err != nil {
+		return "", nil, err
+	}
+	return file.Name(), func() { os.RemoveAll(file.Name()) }, nil
+}
+
+// IsStatic returns true iff the given file is a static binary.
+func IsStatic(filename string) (bool, error) {
+	f, err := elf.Open(filename)
+	if err != nil {
+		return false, err
+	}
+	for _, prog := range f.Progs {
+		if prog.Type == elf.PT_INTERP {
+			return false, nil // Has interpreter.
+		}
+	}
+	return true, nil
+}
+
+// TestIndicesForShard returns indices for this test shard based on the
+// TEST_SHARD_INDEX and TEST_TOTAL_SHARDS environment vars.
+//
+// If either of the env vars are not present, then the function will return all
+// tests. If there are more shards than there are tests, then the returned list
+// may be empty.
+func TestIndicesForShard(numTests int) ([]int, error) {
+	var (
+		shardIndex = 0
+		shardTotal = 1
+	)
+
+	indexStr, totalStr := os.Getenv("TEST_SHARD_INDEX"), os.Getenv("TEST_TOTAL_SHARDS")
+	if indexStr != "" && totalStr != "" {
+		// Parse index and total to ints.
+		var err error
+		shardIndex, err = strconv.Atoi(indexStr)
+		if err != nil {
+			return nil, fmt.Errorf("invalid TEST_SHARD_INDEX %q: %v", indexStr, err)
+		}
+		shardTotal, err = strconv.Atoi(totalStr)
+		if err != nil {
+			return nil, fmt.Errorf("invalid TEST_TOTAL_SHARDS %q: %v", totalStr, err)
+		}
+	}
+
+	// Calculate!
+	var indices []int
+	numBlocks := int(math.Ceil(float64(numTests) / float64(shardTotal)))
+	for i := 0; i < numBlocks; i++ {
+		pick := i*shardTotal + shardIndex
+		if pick < numTests {
+			indices = append(indices, pick)
+		}
+	}
+	return indices, nil
+}
diff --git a/pkg/test/testutil/testutil_runfiles.go b/pkg/test/testutil/testutil_runfiles.go
new file mode 100644
index 000000000..ece9ea9a1
--- /dev/null
+++ b/pkg/test/testutil/testutil_runfiles.go
@@ -0,0 +1,75 @@
+// Copyright 2018 The gVisor 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 testutil
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// FindFile searchs for a file inside the test run environment. It returns the
+// full path to the file. It fails if none or more than one file is found.
+func FindFile(path string) (string, error) {
+	wd, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+
+	// The test root is demarcated by a path element called "__main__". Search for
+	// it backwards from the working directory.
+	root := wd
+	for {
+		dir, name := filepath.Split(root)
+		if name == "__main__" {
+			break
+		}
+		if len(dir) == 0 {
+			return "", fmt.Errorf("directory __main__ not found in %q", wd)
+		}
+		// Remove ending slash to loop around.
+		root = dir[:len(dir)-1]
+	}
+
+	// Annoyingly, bazel adds the build type to the directory path for go
+	// binaries, but not for c++ binaries. We use two different patterns to
+	// to find our file.
+	patterns := []string{
+		// Try the obvious path first.
+		filepath.Join(root, path),
+		// If it was a go binary, use a wildcard to match the build
+		// type. The pattern is: /test-path/__main__/directories/*/file.
+		filepath.Join(root, filepath.Dir(path), "*", filepath.Base(path)),
+	}
+
+	for _, p := range patterns {
+		matches, err := filepath.Glob(p)
+		if err != nil {
+			// "The only possible returned error is ErrBadPattern,
+			// when pattern is malformed." -godoc
+			return "", fmt.Errorf("error globbing %q: %v", p, err)
+		}
+		switch len(matches) {
+		case 0:
+			// Try the next pattern.
+		case 1:
+			// We found it.
+			return matches[0], nil
+		default:
+			return "", fmt.Errorf("more than one match found for %q: %s", path, matches)
+		}
+	}
+	return "", fmt.Errorf("file %q not found", path)
+}