Files
Daniel J Walsh 08cc87636e Vendor in containers/buildah 1.16.1
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
2020-09-11 13:37:37 -04:00

485 lines
16 KiB
Go

package buildah
import (
"archive/tar"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"os"
"path"
"path/filepath"
"strings"
"sync"
"syscall"
"time"
"github.com/containers/buildah/copier"
"github.com/containers/buildah/pkg/chrootuser"
"github.com/containers/storage/pkg/fileutils"
"github.com/containers/storage/pkg/idtools"
"github.com/hashicorp/go-multierror"
"github.com/opencontainers/runtime-spec/specs-go"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
// AddAndCopyOptions holds options for add and copy commands.
type AddAndCopyOptions struct {
// Chown is a spec for the user who should be given ownership over the
// newly-added content, potentially overriding permissions which would
// otherwise be set to 0:0.
Chown string
// PreserveOwnership, if Chown is not set, tells us to avoid setting
// ownership of copied items to 0:0, instead using whatever ownership
// information is already set. Not meaningful for remote sources.
PreserveOwnership bool
// All of the data being copied will pass through Hasher, if set.
// If the sources are URLs or files, their contents will be passed to
// Hasher.
// If the sources include directory trees, Hasher will be passed
// tar-format archives of the directory trees.
Hasher io.Writer
// Excludes is the contents of the .dockerignore file.
Excludes []string
// ContextDir is the base directory for content being copied and
// Excludes patterns.
ContextDir string
// ID mapping options to use when contents to be copied are part of
// another container, and need ownerships to be mapped from the host to
// that container's values before copying them into the container.
IDMappingOptions *IDMappingOptions
// DryRun indicates that the content should be digested, but not actually
// copied into the container.
DryRun bool
// Clear the setuid bit on items being copied. Has no effect on
// archives being extracted, where the bit is always preserved.
StripSetuidBit bool
// Clear the setgid bit on items being copied. Has no effect on
// archives being extracted, where the bit is always preserved.
StripSetgidBit bool
// Clear the sticky bit on items being copied. Has no effect on
// archives being extracted, where the bit is always preserved.
StripStickyBit bool
}
// sourceIsRemote returns true if "source" is a remote location.
func sourceIsRemote(source string) bool {
return strings.HasPrefix(source, "http://") || strings.HasPrefix(source, "https://")
}
// getURL writes a tar archive containing the named content
func getURL(src, mountpoint, renameTarget string, writer io.Writer) error {
url, err := url.Parse(src)
if err != nil {
return errors.Wrapf(err, "error parsing URL %q", url)
}
response, err := http.Get(src)
if err != nil {
return errors.Wrapf(err, "error parsing URL %q", url)
}
defer response.Body.Close()
// Figure out what to name the new content.
name := renameTarget
if name == "" {
name = path.Base(url.Path)
}
// If there's a date on the content, use it. If not, use the Unix epoch
// for compatibility.
date := time.Unix(0, 0).UTC()
lastModified := response.Header.Get("Last-Modified")
if lastModified != "" {
d, err := time.Parse(time.RFC1123, lastModified)
if err != nil {
return errors.Wrapf(err, "error parsing last-modified time %q", lastModified)
}
date = d
}
// Figure out the size of the content.
size := response.ContentLength
responseBody := response.Body
if size < 0 {
// Create a temporary file and copy the content to it, so that
// we can figure out how much content there is.
f, err := ioutil.TempFile(mountpoint, "download")
if err != nil {
return errors.Wrapf(err, "error creating temporary file to hold %q", src)
}
defer os.Remove(f.Name())
defer f.Close()
size, err = io.Copy(f, response.Body)
if err != nil {
return errors.Wrapf(err, "error writing %q to temporary file %q", src, f.Name())
}
_, err = f.Seek(0, io.SeekStart)
if err != nil {
return errors.Wrapf(err, "error setting up to read %q from temporary file %q", src, f.Name())
}
responseBody = f
}
// Write the output archive. Set permissions for compatibility.
tw := tar.NewWriter(writer)
defer tw.Close()
hdr := tar.Header{
Typeflag: tar.TypeReg,
Name: name,
Size: size,
Mode: 0600,
ModTime: date,
}
err = tw.WriteHeader(&hdr)
if err != nil {
return errors.Wrapf(err, "error writing header")
}
_, err = io.Copy(tw, responseBody)
return errors.Wrapf(err, "error writing content from %q to tar stream", src)
}
// Add copies the contents of the specified sources into the container's root
// filesystem, optionally extracting contents of local files that look like
// non-empty archives.
func (b *Builder) Add(destination string, extract bool, options AddAndCopyOptions, sources ...string) error {
mountPoint, err := b.Mount(b.MountLabel)
if err != nil {
return err
}
defer func() {
if err2 := b.Unmount(); err2 != nil {
logrus.Errorf("error unmounting container: %v", err2)
}
}()
contextDir := options.ContextDir
if contextDir == "" {
contextDir = string(os.PathSeparator)
}
// Figure out what sorts of sources we have.
var localSources, remoteSources []string
for _, src := range sources {
if sourceIsRemote(src) {
remoteSources = append(remoteSources, src)
continue
}
localSources = append(localSources, src)
}
// Check how many items our local source specs matched. Each spec
// should have matched at least one item, otherwise we consider it an
// error.
var localSourceStats []*copier.StatsForGlob
if len(localSources) > 0 {
statOptions := copier.StatOptions{
CheckForArchives: extract,
}
localSourceStats, err = copier.Stat(contextDir, contextDir, statOptions, localSources)
if err != nil {
return errors.Wrapf(err, "error checking on sources %v under %q", localSources, contextDir)
}
}
numLocalSourceItems := 0
for _, localSourceStat := range localSourceStats {
if localSourceStat.Error != "" {
errorText := localSourceStat.Error
rel, err := filepath.Rel(contextDir, localSourceStat.Glob)
if err != nil {
errorText = fmt.Sprintf("%v; %s", err, errorText)
}
if strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
errorText = fmt.Sprintf("possible escaping context directory error: %s", errorText)
}
return errors.Errorf("error checking on source %v under %q: %v", localSourceStat.Glob, contextDir, errorText)
}
if len(localSourceStat.Globbed) == 0 {
return errors.Wrapf(syscall.ENOENT, "error checking on source %v under %q: no glob matches", localSourceStat.Glob, contextDir)
}
numLocalSourceItems += len(localSourceStat.Globbed)
}
if numLocalSourceItems+len(remoteSources) == 0 {
return errors.Wrapf(syscall.ENOENT, "no sources %v found", sources)
}
// Find out which user (and group) the destination should belong to.
var chownDirs, chownFiles *idtools.IDPair
var chmodDirs, chmodFiles *os.FileMode
var user specs.User
if options.Chown != "" {
user, _, err = b.user(mountPoint, options.Chown)
if err != nil {
return errors.Wrapf(err, "error looking up UID/GID for %q", options.Chown)
}
}
chownDirs = &idtools.IDPair{UID: int(user.UID), GID: int(user.GID)}
chownFiles = &idtools.IDPair{UID: int(user.UID), GID: int(user.GID)}
if options.Chown == "" && options.PreserveOwnership {
chownDirs = nil
chownFiles = nil
}
// If we have a single source archive to extract, or more than one
// source item, or the destination has a path separator at the end of
// it, and it's not a remote URL, the destination needs to be a
// directory.
if destination == "" || !filepath.IsAbs(destination) {
tmpDestination := filepath.Join(string(os.PathSeparator)+b.WorkDir(), destination)
if destination == "" || strings.HasSuffix(destination, string(os.PathSeparator)) {
destination = tmpDestination + string(os.PathSeparator)
} else {
destination = tmpDestination
}
}
destMustBeDirectory := (len(sources) > 1) || strings.HasSuffix(destination, string(os.PathSeparator))
destCanBeFile := false
if len(sources) == 1 {
if len(remoteSources) == 1 {
destCanBeFile = sourceIsRemote(sources[0])
}
if len(localSources) == 1 {
item := localSourceStats[0].Results[localSourceStats[0].Globbed[0]]
if item.IsDir || (item.IsArchive && extract) {
destMustBeDirectory = true
}
if item.IsRegular {
destCanBeFile = true
}
}
}
// We care if the destination either doesn't exist, or exists and is a
// file. If the source can be a single file, for those cases we treat
// the destination as a file rather than as a directory tree.
renameTarget := ""
extractDirectory := filepath.Join(mountPoint, destination)
statOptions := copier.StatOptions{
CheckForArchives: extract,
}
destStats, err := copier.Stat(mountPoint, filepath.Join(mountPoint, b.WorkDir()), statOptions, []string{extractDirectory})
if err != nil {
return errors.Wrapf(err, "error checking on destination %v", extractDirectory)
}
if (len(destStats) == 0 || len(destStats[0].Globbed) == 0) && !destMustBeDirectory && destCanBeFile {
// destination doesn't exist - extract to parent and rename the incoming file to the destination's name
renameTarget = filepath.Base(extractDirectory)
extractDirectory = filepath.Dir(extractDirectory)
}
if len(destStats) == 1 && len(destStats[0].Globbed) == 1 && destStats[0].Results[destStats[0].Globbed[0]].IsRegular {
if destMustBeDirectory {
return errors.Errorf("destination %v already exists but is not a directory", destination)
}
// destination exists - it's a file, we need to extract to parent and rename the incoming file to the destination's name
renameTarget = filepath.Base(extractDirectory)
extractDirectory = filepath.Dir(extractDirectory)
}
pm, err := fileutils.NewPatternMatcher(options.Excludes)
if err != nil {
return errors.Wrapf(err, "error processing excludes list %v", options.Excludes)
}
// Copy each source in turn.
var srcUIDMap, srcGIDMap []idtools.IDMap
if options.IDMappingOptions != nil {
srcUIDMap, srcGIDMap = convertRuntimeIDMaps(options.IDMappingOptions.UIDMap, options.IDMappingOptions.GIDMap)
}
destUIDMap, destGIDMap := convertRuntimeIDMaps(b.IDMappingOptions.UIDMap, b.IDMappingOptions.GIDMap)
for _, src := range sources {
var multiErr *multierror.Error
var getErr, closeErr, renameErr, putErr error
var wg sync.WaitGroup
if sourceIsRemote(src) {
pipeReader, pipeWriter := io.Pipe()
wg.Add(1)
go func() {
getErr = getURL(src, mountPoint, renameTarget, pipeWriter)
pipeWriter.Close()
wg.Done()
}()
wg.Add(1)
go func() {
b.ContentDigester.Start("")
hashCloser := b.ContentDigester.Hash()
hasher := io.Writer(hashCloser)
if options.Hasher != nil {
hasher = io.MultiWriter(hasher, options.Hasher)
}
if options.DryRun {
_, putErr = io.Copy(hasher, pipeReader)
} else {
putOptions := copier.PutOptions{
UIDMap: destUIDMap,
GIDMap: destGIDMap,
ChownDirs: chownDirs,
ChmodDirs: chmodDirs,
ChownFiles: chownFiles,
ChmodFiles: chmodFiles,
}
putErr = copier.Put(mountPoint, extractDirectory, putOptions, io.TeeReader(pipeReader, hasher))
}
hashCloser.Close()
pipeReader.Close()
wg.Done()
}()
wg.Wait()
if getErr != nil {
getErr = errors.Wrapf(getErr, "error reading %q", src)
}
if putErr != nil {
putErr = errors.Wrapf(putErr, "error storing %q", src)
}
multiErr = multierror.Append(getErr, putErr)
if multiErr != nil && multiErr.ErrorOrNil() != nil {
if len(multiErr.Errors) > 1 {
return multiErr.ErrorOrNil()
}
return multiErr.Errors[0]
}
continue
}
// Dig out the result of running glob+stat on this source spec.
var localSourceStat *copier.StatsForGlob
for _, st := range localSourceStats {
if st.Glob == src {
localSourceStat = st
break
}
}
if localSourceStat == nil {
return errors.Errorf("internal error: should have statted %s, but we didn't?", src)
}
// Iterate through every item that matched the glob.
itemsCopied := 0
for _, glob := range localSourceStat.Globbed {
rel, err := filepath.Rel(contextDir, glob)
if err != nil {
return errors.Wrapf(err, "error computing path of %q", glob)
}
if strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
return errors.Errorf("possible escaping context directory error: %q is outside of %q", glob, contextDir)
}
// Check for dockerignore-style exclusion of this item.
if rel != "." {
matches, err := pm.Matches(filepath.ToSlash(rel)) // nolint:staticcheck
if err != nil {
return errors.Wrapf(err, "error checking if %q(%q) is excluded", glob, rel)
}
if matches {
continue
}
}
st := localSourceStat.Results[glob]
pipeReader, pipeWriter := io.Pipe()
wg.Add(1)
go func() {
renamedItems := 0
writer := io.WriteCloser(pipeWriter)
if renameTarget != "" {
writer = newTarFilterer(writer, func(hdr *tar.Header) (bool, bool, io.Reader) {
hdr.Name = renameTarget
renamedItems++
return false, false, nil
})
}
getOptions := copier.GetOptions{
UIDMap: srcUIDMap,
GIDMap: srcGIDMap,
Excludes: options.Excludes,
ExpandArchives: extract,
StripSetuidBit: options.StripSetuidBit,
StripSetgidBit: options.StripSetgidBit,
StripStickyBit: options.StripStickyBit,
}
getErr = copier.Get(contextDir, contextDir, getOptions, []string{glob}, writer)
closeErr = writer.Close()
if renameTarget != "" && renamedItems > 1 {
renameErr = errors.Errorf("internal error: renamed %d items when we expected to only rename 1", renamedItems)
}
wg.Done()
}()
wg.Add(1)
go func() {
if st.IsDir {
b.ContentDigester.Start("dir")
} else {
b.ContentDigester.Start("file")
}
hashCloser := b.ContentDigester.Hash()
hasher := io.Writer(hashCloser)
if options.Hasher != nil {
hasher = io.MultiWriter(hasher, options.Hasher)
}
if options.DryRun {
_, putErr = io.Copy(hasher, pipeReader)
} else {
putOptions := copier.PutOptions{
UIDMap: destUIDMap,
GIDMap: destGIDMap,
ChownDirs: chownDirs,
ChmodDirs: chmodDirs,
ChownFiles: chownFiles,
ChmodFiles: chmodFiles,
}
putErr = copier.Put(mountPoint, extractDirectory, putOptions, io.TeeReader(pipeReader, hasher))
}
hashCloser.Close()
pipeReader.Close()
wg.Done()
}()
wg.Wait()
if getErr != nil {
getErr = errors.Wrapf(getErr, "error reading %q", src)
}
if closeErr != nil {
closeErr = errors.Wrapf(closeErr, "error closing %q", src)
}
if renameErr != nil {
renameErr = errors.Wrapf(renameErr, "error renaming %q", src)
}
if putErr != nil {
putErr = errors.Wrapf(putErr, "error storing %q", src)
}
multiErr = multierror.Append(getErr, closeErr, renameErr, putErr)
if multiErr != nil && multiErr.ErrorOrNil() != nil {
if len(multiErr.Errors) > 1 {
return multiErr.ErrorOrNil()
}
return multiErr.Errors[0]
}
itemsCopied++
}
if itemsCopied == 0 {
return errors.Wrapf(syscall.ENOENT, "no items matching glob %q copied (%d filtered)", localSourceStat.Glob, len(localSourceStat.Globbed))
}
}
return nil
}
// user returns the user (and group) information which the destination should belong to.
func (b *Builder) user(mountPoint string, userspec string) (specs.User, string, error) {
if userspec == "" {
userspec = b.User()
}
uid, gid, homeDir, err := chrootuser.GetUser(mountPoint, userspec)
u := specs.User{
UID: uid,
GID: gid,
Username: userspec,
}
if !strings.Contains(userspec, ":") {
groups, err2 := chrootuser.GetAdditionalGroupsForUser(mountPoint, uint64(u.UID))
if err2 != nil {
if errors.Cause(err2) != chrootuser.ErrNoSuchUser && err == nil {
err = err2
}
} else {
u.AdditionalGids = groups
}
}
return u, homeDir, err
}