464 lines
12 KiB
Go
464 lines
12 KiB
Go
// Copyright 2018 Google LLC
|
|
//
|
|
// 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"
|
|
"encoding/base32"
|
|
"encoding/json"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"math/rand"
|
|
"net/http"
|
|
"os"
|
|
"os/exec"
|
|
"os/signal"
|
|
"path/filepath"
|
|
"runtime"
|
|
"strings"
|
|
"sync"
|
|
"sync/atomic"
|
|
"syscall"
|
|
"time"
|
|
|
|
"github.com/cenkalti/backoff"
|
|
specs "github.com/opencontainers/runtime-spec/specs-go"
|
|
"github.com/syndtr/gocapability/capability"
|
|
"gvisor.googlesource.com/gvisor/runsc/boot"
|
|
"gvisor.googlesource.com/gvisor/runsc/specutils"
|
|
)
|
|
|
|
func init() {
|
|
rand.Seed(time.Now().UnixNano())
|
|
}
|
|
|
|
// RaceEnabled is set to true if it was built with '--race' option.
|
|
var RaceEnabled = false
|
|
|
|
// 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
|
|
}
|
|
|
|
// 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
|
|
}
|
|
|
|
// 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)
|
|
}
|
|
|
|
// TestConfig returns the default configuration to use in tests. Note that
|
|
// 'RootDir' must be set by caller if required.
|
|
func TestConfig() *boot.Config {
|
|
return &boot.Config{
|
|
Debug: true,
|
|
LogFormat: "text",
|
|
LogPackets: true,
|
|
Network: boot.NetworkNone,
|
|
Strace: true,
|
|
FileAccess: boot.FileAccessExclusive,
|
|
TestOnlyAllowRunAsCurrentUserWithoutChroot: true,
|
|
}
|
|
}
|
|
|
|
// TestConfigWithRoot returns the default configuration to use in tests.
|
|
func TestConfigWithRoot(rootDir string) *boot.Config {
|
|
conf := TestConfig()
|
|
conf.RootDir = rootDir
|
|
return conf
|
|
}
|
|
|
|
// 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{
|
|
// 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, error) {
|
|
rootDir, err := ioutil.TempDir(TmpDir(), "containers")
|
|
if err != nil {
|
|
return "", fmt.Errorf("error creating root dir: %v", err)
|
|
}
|
|
return 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, err error) {
|
|
rootDir, err = SetupRootDir()
|
|
if err != nil {
|
|
return "", "", err
|
|
}
|
|
conf.RootDir = rootDir
|
|
bundleDir, err = SetupBundleDir(spec)
|
|
return rootDir, bundleDir, err
|
|
}
|
|
|
|
// SetupBundleDir creates a bundle dir and writes the spec to config.json.
|
|
func SetupBundleDir(spec *specs.Spec) (bundleDir string, err error) {
|
|
bundleDir, err = ioutil.TempDir(TmpDir(), "bundle")
|
|
if err != nil {
|
|
return "", fmt.Errorf("error creating bundle dir: %v", err)
|
|
}
|
|
|
|
if err = writeSpec(bundleDir, spec); err != nil {
|
|
return "", fmt.Errorf("error writing spec: %v", err)
|
|
}
|
|
return bundleDir, 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)
|
|
}
|
|
|
|
// UniqueContainerID generates a unique 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 UniqueContainerID() 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())
|
|
}
|
|
// base32 encode the random bytes, so that the name is a valid
|
|
// container id and can be used as a socket name in the filesystem.
|
|
return fmt.Sprintf("test-container-%s", base32.StdEncoding.EncodeToString(b))
|
|
}
|
|
|
|
// 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()
|
|
|
|
out, err := os.Create(dst)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer out.Close()
|
|
|
|
_, 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 {
|
|
resp, err := http.Get(fmt.Sprintf("http://localhost:%d/", port))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
resp.Body.Close()
|
|
return nil
|
|
}
|
|
return Poll(cb, timeout)
|
|
}
|
|
|
|
// RunAsRoot ensures the test runs with CAP_SYS_ADMIN and CAP_SYS_CHROOT. If
|
|
// needed it will create a new user namespace and re-execute the test as root
|
|
// inside of the namespace. This function returns when it's running as root. If
|
|
// it needs to create another process, it will exit from there and not return.
|
|
func RunAsRoot() {
|
|
if specutils.HasCapabilities(capability.CAP_SYS_ADMIN, capability.CAP_SYS_CHROOT) {
|
|
return
|
|
}
|
|
|
|
fmt.Println("*** Re-running test as root in new user namespace ***")
|
|
|
|
// Current process doesn't have CAP_SYS_ADMIN, create user namespace and run
|
|
// as root inside that namespace to get it.
|
|
runtime.LockOSThread()
|
|
defer runtime.UnlockOSThread()
|
|
|
|
cmd := exec.Command("/proc/self/exe", os.Args[1:]...)
|
|
cmd.SysProcAttr = &syscall.SysProcAttr{
|
|
Cloneflags: syscall.CLONE_NEWUSER | syscall.CLONE_NEWNS,
|
|
// Set current user/group as root inside the namespace.
|
|
UidMappings: []syscall.SysProcIDMap{
|
|
{ContainerID: 0, HostID: os.Getuid(), Size: 1},
|
|
},
|
|
GidMappings: []syscall.SysProcIDMap{
|
|
{ContainerID: 0, HostID: os.Getgid(), Size: 1},
|
|
},
|
|
GidMappingsEnableSetgroups: false,
|
|
Credential: &syscall.Credential{
|
|
Uid: 0,
|
|
Gid: 0,
|
|
},
|
|
}
|
|
cmd.Env = os.Environ()
|
|
cmd.Stdin = os.Stdin
|
|
cmd.Stdout = os.Stdout
|
|
cmd.Stderr = os.Stderr
|
|
if err := cmd.Run(); err != nil {
|
|
if exit, ok := err.(*exec.ExitError); ok {
|
|
if ws, ok := exit.Sys().(syscall.WaitStatus); ok {
|
|
os.Exit(ws.ExitStatus())
|
|
}
|
|
os.Exit(-1)
|
|
}
|
|
panic(fmt.Sprint("error running child process:", err.Error()))
|
|
}
|
|
os.Exit(0)
|
|
}
|
|
|
|
// 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
|
|
}
|
|
|
|
// RetryEintr retries the function until an error different than EINTR is
|
|
// returned.
|
|
func RetryEintr(f func() (uintptr, uintptr, error)) (uintptr, uintptr, error) {
|
|
for {
|
|
r1, r2, err := f()
|
|
if err != syscall.EINTR {
|
|
return r1, r2, err
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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.
|
|
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 nil
|
|
}
|
|
|
|
// WriteTmpFile writes text to a temporary file, closes the file, and returns
|
|
// the name of the file.
|
|
func WriteTmpFile(pattern, text string) (string, error) {
|
|
file, err := ioutil.TempFile(TmpDir(), pattern)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
defer file.Close()
|
|
if _, err := file.Write([]byte(text)); err != nil {
|
|
return "", err
|
|
}
|
|
return file.Name(), nil
|
|
}
|