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moby--moby/utils/utils.go
Michael Crosby edaf23b7a7 Merge pull request #10145 from duglin/Issue10141
Docker run -e FOO should erase FOO if FOO isn't set in client env
2015-01-21 14:16:51 -08:00

547 lines
13 KiB
Go

package utils
import (
"bufio"
"bytes"
"crypto/rand"
"crypto/sha1"
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
"os/exec"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
"sync"
log "github.com/Sirupsen/logrus"
"github.com/docker/docker/dockerversion"
"github.com/docker/docker/pkg/archive"
"github.com/docker/docker/pkg/fileutils"
"github.com/docker/docker/pkg/ioutils"
)
type KeyValuePair struct {
Key string
Value string
}
var (
validHex = regexp.MustCompile(`^([a-f0-9]{64})$`)
)
// Request a given URL and return an io.Reader
func Download(url string) (resp *http.Response, err error) {
if resp, err = http.Get(url); err != nil {
return nil, err
}
if resp.StatusCode >= 400 {
return nil, fmt.Errorf("Got HTTP status code >= 400: %s", resp.Status)
}
return resp, nil
}
func Trunc(s string, maxlen int) string {
if len(s) <= maxlen {
return s
}
return s[:maxlen]
}
// Figure out the absolute path of our own binary (if it's still around).
func SelfPath() string {
path, err := exec.LookPath(os.Args[0])
if err != nil {
if os.IsNotExist(err) {
return ""
}
if execErr, ok := err.(*exec.Error); ok && os.IsNotExist(execErr.Err) {
return ""
}
panic(err)
}
path, err = filepath.Abs(path)
if err != nil {
if os.IsNotExist(err) {
return ""
}
panic(err)
}
return path
}
func dockerInitSha1(target string) string {
f, err := os.Open(target)
if err != nil {
return ""
}
defer f.Close()
h := sha1.New()
_, err = io.Copy(h, f)
if err != nil {
return ""
}
return hex.EncodeToString(h.Sum(nil))
}
func isValidDockerInitPath(target string, selfPath string) bool { // target and selfPath should be absolute (InitPath and SelfPath already do this)
if target == "" {
return false
}
if dockerversion.IAMSTATIC == "true" {
if selfPath == "" {
return false
}
if target == selfPath {
return true
}
targetFileInfo, err := os.Lstat(target)
if err != nil {
return false
}
selfPathFileInfo, err := os.Lstat(selfPath)
if err != nil {
return false
}
return os.SameFile(targetFileInfo, selfPathFileInfo)
}
return dockerversion.INITSHA1 != "" && dockerInitSha1(target) == dockerversion.INITSHA1
}
// Figure out the path of our dockerinit (which may be SelfPath())
func DockerInitPath(localCopy string) string {
selfPath := SelfPath()
if isValidDockerInitPath(selfPath, selfPath) {
// if we're valid, don't bother checking anything else
return selfPath
}
var possibleInits = []string{
localCopy,
dockerversion.INITPATH,
filepath.Join(filepath.Dir(selfPath), "dockerinit"),
// FHS 3.0 Draft: "/usr/libexec includes internal binaries that are not intended to be executed directly by users or shell scripts. Applications may use a single subdirectory under /usr/libexec."
// http://www.linuxbase.org/betaspecs/fhs/fhs.html#usrlibexec
"/usr/libexec/docker/dockerinit",
"/usr/local/libexec/docker/dockerinit",
// FHS 2.3: "/usr/lib includes object files, libraries, and internal binaries that are not intended to be executed directly by users or shell scripts."
// http://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html#USRLIBLIBRARIESFORPROGRAMMINGANDPA
"/usr/lib/docker/dockerinit",
"/usr/local/lib/docker/dockerinit",
}
for _, dockerInit := range possibleInits {
if dockerInit == "" {
continue
}
path, err := exec.LookPath(dockerInit)
if err == nil {
path, err = filepath.Abs(path)
if err != nil {
// LookPath already validated that this file exists and is executable (following symlinks), so how could Abs fail?
panic(err)
}
if isValidDockerInitPath(path, selfPath) {
return path
}
}
}
return ""
}
func GetTotalUsedFds() int {
if fds, err := ioutil.ReadDir(fmt.Sprintf("/proc/%d/fd", os.Getpid())); err != nil {
log.Errorf("Error opening /proc/%d/fd: %s", os.Getpid(), err)
} else {
return len(fds)
}
return -1
}
// TruncateID returns a shorthand version of a string identifier for convenience.
// A collision with other shorthands is very unlikely, but possible.
// In case of a collision a lookup with TruncIndex.Get() will fail, and the caller
// will need to use a langer prefix, or the full-length Id.
func TruncateID(id string) string {
shortLen := 12
if len(id) < shortLen {
shortLen = len(id)
}
return id[:shortLen]
}
// GenerateRandomID returns an unique id
func GenerateRandomID() string {
for {
id := make([]byte, 32)
if _, err := io.ReadFull(rand.Reader, id); err != nil {
panic(err) // This shouldn't happen
}
value := hex.EncodeToString(id)
// if we try to parse the truncated for as an int and we don't have
// an error then the value is all numberic and causes issues when
// used as a hostname. ref #3869
if _, err := strconv.ParseInt(TruncateID(value), 10, 64); err == nil {
continue
}
return value
}
}
func ValidateID(id string) error {
if ok := validHex.MatchString(id); !ok {
err := fmt.Errorf("image ID '%s' is invalid", id)
return err
}
return nil
}
// Code c/c from io.Copy() modified to handle escape sequence
func CopyEscapable(dst io.Writer, src io.ReadCloser) (written int64, err error) {
buf := make([]byte, 32*1024)
for {
nr, er := src.Read(buf)
if nr > 0 {
// ---- Docker addition
// char 16 is C-p
if nr == 1 && buf[0] == 16 {
nr, er = src.Read(buf)
// char 17 is C-q
if nr == 1 && buf[0] == 17 {
if err := src.Close(); err != nil {
return 0, err
}
return 0, nil
}
}
// ---- End of docker
nw, ew := dst.Write(buf[0:nr])
if nw > 0 {
written += int64(nw)
}
if ew != nil {
err = ew
break
}
if nr != nw {
err = io.ErrShortWrite
break
}
}
if er == io.EOF {
break
}
if er != nil {
err = er
break
}
}
return written, err
}
func HashData(src io.Reader) (string, error) {
h := sha256.New()
if _, err := io.Copy(h, src); err != nil {
return "", err
}
return "sha256:" + hex.EncodeToString(h.Sum(nil)), nil
}
type WriteFlusher struct {
sync.Mutex
w io.Writer
flusher http.Flusher
}
func (wf *WriteFlusher) Write(b []byte) (n int, err error) {
wf.Lock()
defer wf.Unlock()
n, err = wf.w.Write(b)
wf.flusher.Flush()
return n, err
}
// Flush the stream immediately.
func (wf *WriteFlusher) Flush() {
wf.Lock()
defer wf.Unlock()
wf.flusher.Flush()
}
func NewWriteFlusher(w io.Writer) *WriteFlusher {
var flusher http.Flusher
if f, ok := w.(http.Flusher); ok {
flusher = f
} else {
flusher = &ioutils.NopFlusher{}
}
return &WriteFlusher{w: w, flusher: flusher}
}
func NewHTTPRequestError(msg string, res *http.Response) error {
return &JSONError{
Message: msg,
Code: res.StatusCode,
}
}
// An StatusError reports an unsuccessful exit by a command.
type StatusError struct {
Status string
StatusCode int
}
func (e *StatusError) Error() string {
return fmt.Sprintf("Status: %s, Code: %d", e.Status, e.StatusCode)
}
func quote(word string, buf *bytes.Buffer) {
// Bail out early for "simple" strings
if word != "" && !strings.ContainsAny(word, "\\'\"`${[|&;<>()~*?! \t\n") {
buf.WriteString(word)
return
}
buf.WriteString("'")
for i := 0; i < len(word); i++ {
b := word[i]
if b == '\'' {
// Replace literal ' with a close ', a \', and a open '
buf.WriteString("'\\''")
} else {
buf.WriteByte(b)
}
}
buf.WriteString("'")
}
// Take a list of strings and escape them so they will be handled right
// when passed as arguments to an program via a shell
func ShellQuoteArguments(args []string) string {
var buf bytes.Buffer
for i, arg := range args {
if i != 0 {
buf.WriteByte(' ')
}
quote(arg, &buf)
}
return buf.String()
}
var globalTestID string
// TestDirectory creates a new temporary directory and returns its path.
// The contents of directory at path `templateDir` is copied into the
// new directory.
func TestDirectory(templateDir string) (dir string, err error) {
if globalTestID == "" {
globalTestID = RandomString()[:4]
}
prefix := fmt.Sprintf("docker-test%s-%s-", globalTestID, GetCallerName(2))
if prefix == "" {
prefix = "docker-test-"
}
dir, err = ioutil.TempDir("", prefix)
if err = os.Remove(dir); err != nil {
return
}
if templateDir != "" {
if err = archive.CopyWithTar(templateDir, dir); err != nil {
return
}
}
return
}
// GetCallerName introspects the call stack and returns the name of the
// function `depth` levels down in the stack.
func GetCallerName(depth int) string {
// Use the caller function name as a prefix.
// This helps trace temp directories back to their test.
pc, _, _, _ := runtime.Caller(depth + 1)
callerLongName := runtime.FuncForPC(pc).Name()
parts := strings.Split(callerLongName, ".")
callerShortName := parts[len(parts)-1]
return callerShortName
}
func CopyFile(src, dst string) (int64, error) {
if src == dst {
return 0, nil
}
sf, err := os.Open(src)
if err != nil {
return 0, err
}
defer sf.Close()
if err := os.Remove(dst); err != nil && !os.IsNotExist(err) {
return 0, err
}
df, err := os.Create(dst)
if err != nil {
return 0, err
}
defer df.Close()
return io.Copy(df, sf)
}
// ReplaceOrAppendValues returns the defaults with the overrides either
// replaced by env key or appended to the list
func ReplaceOrAppendEnvValues(defaults, overrides []string) []string {
cache := make(map[string]int, len(defaults))
for i, e := range defaults {
parts := strings.SplitN(e, "=", 2)
cache[parts[0]] = i
}
for _, value := range overrides {
// Values w/o = means they want this env to be removed/unset.
if !strings.Contains(value, "=") {
if i, exists := cache[value]; exists {
defaults[i] = "" // Used to indicate it should be removed
}
continue
}
// Just do a normal set/update
parts := strings.SplitN(value, "=", 2)
if i, exists := cache[parts[0]]; exists {
defaults[i] = value
} else {
defaults = append(defaults, value)
}
}
// Now remove all entries that we want to "unset"
for i := 0; i < len(defaults); i++ {
if defaults[i] == "" {
defaults = append(defaults[:i], defaults[i+1:]...)
i--
}
}
return defaults
}
func DoesEnvExist(name string) bool {
for _, entry := range os.Environ() {
parts := strings.SplitN(entry, "=", 2)
if parts[0] == name {
return true
}
}
return false
}
// ReadSymlinkedDirectory returns the target directory of a symlink.
// The target of the symbolic link may not be a file.
func ReadSymlinkedDirectory(path string) (string, error) {
var realPath string
var err error
if realPath, err = filepath.Abs(path); err != nil {
return "", fmt.Errorf("unable to get absolute path for %s: %s", path, err)
}
if realPath, err = filepath.EvalSymlinks(realPath); err != nil {
return "", fmt.Errorf("failed to canonicalise path for %s: %s", path, err)
}
realPathInfo, err := os.Stat(realPath)
if err != nil {
return "", fmt.Errorf("failed to stat target '%s' of '%s': %s", realPath, path, err)
}
if !realPathInfo.Mode().IsDir() {
return "", fmt.Errorf("canonical path points to a file '%s'", realPath)
}
return realPath, nil
}
// ValidateContextDirectory checks if all the contents of the directory
// can be read and returns an error if some files can't be read
// symlinks which point to non-existing files don't trigger an error
func ValidateContextDirectory(srcPath string, excludes []string) error {
return filepath.Walk(filepath.Join(srcPath, "."), func(filePath string, f os.FileInfo, err error) error {
// skip this directory/file if it's not in the path, it won't get added to the context
if relFilePath, err := filepath.Rel(srcPath, filePath); err != nil {
return err
} else if skip, err := fileutils.Matches(relFilePath, excludes); err != nil {
return err
} else if skip {
if f.IsDir() {
return filepath.SkipDir
}
return nil
}
if err != nil {
if os.IsPermission(err) {
return fmt.Errorf("can't stat '%s'", filePath)
}
if os.IsNotExist(err) {
return nil
}
return err
}
// skip checking if symlinks point to non-existing files, such symlinks can be useful
// also skip named pipes, because they hanging on open
if f.Mode()&(os.ModeSymlink|os.ModeNamedPipe) != 0 {
return nil
}
if !f.IsDir() {
currentFile, err := os.Open(filePath)
if err != nil && os.IsPermission(err) {
return fmt.Errorf("no permission to read from '%s'", filePath)
}
currentFile.Close()
}
return nil
})
}
func StringsContainsNoCase(slice []string, s string) bool {
for _, ss := range slice {
if strings.ToLower(s) == strings.ToLower(ss) {
return true
}
}
return false
}
// Reads a .dockerignore file and returns the list of file patterns
// to ignore. Note this will trim whitespace from each line as well
// as use GO's "clean" func to get the shortest/cleanest path for each.
func ReadDockerIgnore(path string) ([]string, error) {
// Note that a missing .dockerignore file isn't treated as an error
reader, err := os.Open(path)
if err != nil {
if !os.IsNotExist(err) {
return nil, fmt.Errorf("Error reading '%s': %v", path, err)
}
return nil, nil
}
defer reader.Close()
scanner := bufio.NewScanner(reader)
var excludes []string
for scanner.Scan() {
pattern := strings.TrimSpace(scanner.Text())
if pattern == "" {
continue
}
pattern = filepath.Clean(pattern)
excludes = append(excludes, pattern)
}
if err = scanner.Err(); err != nil {
return nil, fmt.Errorf("Error reading '%s': %v", path, err)
}
return excludes, nil
}