1 files changed, 494 insertions, 0 deletions
diff --git a/vendor/github.com/containers/buildah/util/util.go b/vendor/github.com/containers/buildah/util/util.go
new file mode 100644
index 000000000..93323232d
--- /dev/null
+++ b/vendor/github.com/containers/buildah/util/util.go
@@ -0,0 +1,494 @@
+package util
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/containers/image/directory"
+	dockerarchive "github.com/containers/image/docker/archive"
+	"github.com/containers/image/docker/reference"
+	ociarchive "github.com/containers/image/oci/archive"
+	"github.com/containers/image/pkg/sysregistriesv2"
+	"github.com/containers/image/signature"
+	is "github.com/containers/image/storage"
+	"github.com/containers/image/tarball"
+	"github.com/containers/image/types"
+	"github.com/containers/storage"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/docker/distribution/registry/api/errcode"
+	"github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	minimumTruncatedIDLength = 3
+)
+
+var (
+	// RegistryDefaultPathPrefix contains a per-registry listing of default prefixes
+	// to prepend to image names that only contain a single path component.
+	RegistryDefaultPathPrefix = map[string]string{
+		"index.docker.io": "library",
+		"docker.io":       "library",
+	}
+	// Transports contains the possible transports used for images
+	Transports = map[string]string{
+		dockerarchive.Transport.Name(): "",
+		ociarchive.Transport.Name():    "",
+		directory.Transport.Name():     "",
+		tarball.Transport.Name():       "",
+	}
+	// DockerArchive is the transport we prepend to an image name
+	// when saving to docker-archive
+	DockerArchive = dockerarchive.Transport.Name()
+	// OCIArchive is the transport we prepend to an image name
+	// when saving to oci-archive
+	OCIArchive = ociarchive.Transport.Name()
+	// DirTransport is the transport for pushing and pulling
+	// images to and from a directory
+	DirTransport = directory.Transport.Name()
+	// TarballTransport is the transport for importing a tar archive
+	// and creating a filesystem image
+	TarballTransport = tarball.Transport.Name()
+)
+
+// ResolveName checks if name is a valid image name, and if that name doesn't
+// include a domain portion, returns a list of the names which it might
+// correspond to in the set of configured registries.
+func ResolveName(name string, firstRegistry string, sc *types.SystemContext, store storage.Store) ([]string, error) {
+	if name == "" {
+		return nil, nil
+	}
+
+	// Maybe it's a truncated image ID.  Don't prepend a registry name, then.
+	if len(name) >= minimumTruncatedIDLength {
+		if img, err := store.Image(name); err == nil && img != nil && strings.HasPrefix(img.ID, name) {
+			// It's a truncated version of the ID of an image that's present in local storage;
+			// we need only expand the ID.
+			return []string{img.ID}, nil
+		}
+	}
+
+	// If the image includes a transport's name as a prefix, use it as-is.
+	split := strings.SplitN(name, ":", 2)
+	if len(split) == 2 {
+		if _, ok := Transports[split[0]]; ok {
+			return []string{split[1]}, nil
+		}
+	}
+
+	// If the image name already included a domain component, we're done.
+	named, err := reference.ParseNormalizedNamed(name)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error parsing image name %q", name)
+	}
+	if named.String() == name {
+		// Parsing produced the same result, so there was a domain name in there to begin with.
+		return []string{name}, nil
+	}
+	if reference.Domain(named) != "" && RegistryDefaultPathPrefix[reference.Domain(named)] != "" {
+		// If this domain can cause us to insert something in the middle, check if that happened.
+		repoPath := reference.Path(named)
+		domain := reference.Domain(named)
+		tag := ""
+		if tagged, ok := named.(reference.Tagged); ok {
+			tag = ":" + tagged.Tag()
+		}
+		digest := ""
+		if digested, ok := named.(reference.Digested); ok {
+			digest = "@" + digested.Digest().String()
+		}
+		defaultPrefix := RegistryDefaultPathPrefix[reference.Domain(named)] + "/"
+		if strings.HasPrefix(repoPath, defaultPrefix) && path.Join(domain, repoPath[len(defaultPrefix):])+tag+digest == name {
+			// Yup, parsing just inserted a bit in the middle, so there was a domain name there to begin with.
+			return []string{name}, nil
+		}
+	}
+
+	// Figure out the list of registries.
+	var registries []string
+	allRegistries, err := sysregistriesv2.GetRegistries(sc)
+	if err != nil {
+		logrus.Debugf("unable to read configured registries to complete %q: %v", name, err)
+		registries = []string{}
+	}
+	for _, registry := range sysregistriesv2.FindUnqualifiedSearchRegistries(allRegistries) {
+		if !registry.Blocked {
+			registries = append(registries, registry.URL)
+		}
+	}
+
+	// Create all of the combinations.  Some registries need an additional component added, so
+	// use our lookaside map to keep track of them.  If there are no configured registries, we'll
+	// return a name using "localhost" as the registry name.
+	candidates := []string{}
+	initRegistries := []string{"localhost"}
+	if firstRegistry != "" && firstRegistry != "localhost" {
+		initRegistries = append([]string{firstRegistry}, initRegistries...)
+	}
+	for _, registry := range append(initRegistries, registries...) {
+		if registry == "" {
+			continue
+		}
+		middle := ""
+		if prefix, ok := RegistryDefaultPathPrefix[registry]; ok && strings.IndexRune(name, '/') == -1 {
+			middle = prefix
+		}
+		candidate := path.Join(registry, middle, name)
+		candidates = append(candidates, candidate)
+	}
+	return candidates, nil
+}
+
+// ExpandNames takes unqualified names, parses them as image names, and returns
+// the fully expanded result, including a tag.  Names which don't include a registry
+// name will be marked for the most-preferred registry (i.e., the first one in our
+// configuration).
+func ExpandNames(names []string, firstRegistry string, systemContext *types.SystemContext, store storage.Store) ([]string, error) {
+	expanded := make([]string, 0, len(names))
+	for _, n := range names {
+		var name reference.Named
+		nameList, err := ResolveName(n, firstRegistry, systemContext, store)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error parsing name %q", n)
+		}
+		if len(nameList) == 0 {
+			named, err := reference.ParseNormalizedNamed(n)
+			if err != nil {
+				return nil, errors.Wrapf(err, "error parsing name %q", n)
+			}
+			name = named
+		} else {
+			named, err := reference.ParseNormalizedNamed(nameList[0])
+			if err != nil {
+				return nil, errors.Wrapf(err, "error parsing name %q", nameList[0])
+			}
+			name = named
+		}
+		name = reference.TagNameOnly(name)
+		tag := ""
+		digest := ""
+		if tagged, ok := name.(reference.NamedTagged); ok {
+			tag = ":" + tagged.Tag()
+		}
+		if digested, ok := name.(reference.Digested); ok {
+			digest = "@" + digested.Digest().String()
+		}
+		expanded = append(expanded, name.Name()+tag+digest)
+	}
+	return expanded, nil
+}
+
+// FindImage locates the locally-stored image which corresponds to a given name.
+func FindImage(store storage.Store, firstRegistry string, systemContext *types.SystemContext, image string) (types.ImageReference, *storage.Image, error) {
+	var ref types.ImageReference
+	var img *storage.Image
+	var err error
+	names, err := ResolveName(image, firstRegistry, systemContext, store)
+	if err != nil {
+		return nil, nil, errors.Wrapf(err, "error parsing name %q", image)
+	}
+	for _, name := range names {
+		ref, err = is.Transport.ParseStoreReference(store, name)
+		if err != nil {
+			logrus.Debugf("error parsing reference to image %q: %v", name, err)
+			continue
+		}
+		img, err = is.Transport.GetStoreImage(store, ref)
+		if err != nil {
+			img2, err2 := store.Image(name)
+			if err2 != nil {
+				logrus.Debugf("error locating image %q: %v", name, err2)
+				continue
+			}
+			img = img2
+		}
+		break
+	}
+	if ref == nil || img == nil {
+		return nil, nil, errors.Wrapf(err, "error locating image with name %q", image)
+	}
+	return ref, img, nil
+}
+
+// AddImageNames adds the specified names to the specified image.
+func AddImageNames(store storage.Store, firstRegistry string, systemContext *types.SystemContext, image *storage.Image, addNames []string) error {
+	names, err := ExpandNames(addNames, firstRegistry, systemContext, store)
+	if err != nil {
+		return err
+	}
+	err = store.SetNames(image.ID, append(image.Names, names...))
+	if err != nil {
+		return errors.Wrapf(err, "error adding names (%v) to image %q", names, image.ID)
+	}
+	return nil
+}
+
+// GetFailureCause checks the type of the error "err" and returns a new
+// error message that reflects the reason of the failure.
+// In case err type is not a familiar one the error "defaultError" is returned.
+func GetFailureCause(err, defaultError error) error {
+	switch nErr := errors.Cause(err).(type) {
+	case errcode.Errors:
+		return err
+	case errcode.Error, *url.Error:
+		return nErr
+	default:
+		return defaultError
+	}
+}
+
+// WriteError writes `lastError` into `w` if not nil and return the next error `err`
+func WriteError(w io.Writer, err error, lastError error) error {
+	if lastError != nil {
+		fmt.Fprintln(w, lastError)
+	}
+	return err
+}
+
+// Runtime is the default command to use to run the container.
+func Runtime() string {
+	runtime := os.Getenv("BUILDAH_RUNTIME")
+	if runtime != "" {
+		return runtime
+	}
+	return DefaultRuntime
+}
+
+// StringInSlice returns a boolean indicating if the exact value s is present
+// in the slice slice.
+func StringInSlice(s string, slice []string) bool {
+	for _, v := range slice {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
+// GetHostIDs uses ID mappings to compute the host-level IDs that will
+// correspond to a UID/GID pair in the container.
+func GetHostIDs(uidmap, gidmap []specs.LinuxIDMapping, uid, gid uint32) (uint32, uint32, error) {
+	uidMapped := true
+	for _, m := range uidmap {
+		uidMapped = false
+		if uid >= m.ContainerID && uid < m.ContainerID+m.Size {
+			uid = (uid - m.ContainerID) + m.HostID
+			uidMapped = true
+			break
+		}
+	}
+	if !uidMapped {
+		return 0, 0, errors.Errorf("container uses ID mappings, but doesn't map UID %d", uid)
+	}
+	gidMapped := true
+	for _, m := range gidmap {
+		gidMapped = false
+		if gid >= m.ContainerID && gid < m.ContainerID+m.Size {
+			gid = (gid - m.ContainerID) + m.HostID
+			gidMapped = true
+			break
+		}
+	}
+	if !gidMapped {
+		return 0, 0, errors.Errorf("container uses ID mappings, but doesn't map GID %d", gid)
+	}
+	return uid, gid, nil
+}
+
+// GetHostRootIDs uses ID mappings in spec to compute the host-level IDs that will
+// correspond to UID/GID 0/0 in the container.
+func GetHostRootIDs(spec *specs.Spec) (uint32, uint32, error) {
+	if spec.Linux == nil {
+		return 0, 0, nil
+	}
+	return GetHostIDs(spec.Linux.UIDMappings, spec.Linux.GIDMappings, 0, 0)
+}
+
+// getHostIDMappings reads mappings from the named node under /proc.
+func getHostIDMappings(path string) ([]specs.LinuxIDMapping, error) {
+	var mappings []specs.LinuxIDMapping
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error reading ID mappings from %q", path)
+	}
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		fields := strings.Fields(line)
+		if len(fields) != 3 {
+			return nil, errors.Errorf("line %q from %q has %d fields, not 3", line, path, len(fields))
+		}
+		cid, err := strconv.ParseUint(fields[0], 10, 32)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error parsing container ID value %q from line %q in %q", fields[0], line, path)
+		}
+		hid, err := strconv.ParseUint(fields[1], 10, 32)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error parsing host ID value %q from line %q in %q", fields[1], line, path)
+		}
+		size, err := strconv.ParseUint(fields[2], 10, 32)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error parsing size value %q from line %q in %q", fields[2], line, path)
+		}
+		mappings = append(mappings, specs.LinuxIDMapping{ContainerID: uint32(cid), HostID: uint32(hid), Size: uint32(size)})
+	}
+	return mappings, nil
+}
+
+// GetHostIDMappings reads mappings for the specified process (or the current
+// process if pid is "self" or an empty string) from the kernel.
+func GetHostIDMappings(pid string) ([]specs.LinuxIDMapping, []specs.LinuxIDMapping, error) {
+	if pid == "" {
+		pid = "self"
+	}
+	uidmap, err := getHostIDMappings(fmt.Sprintf("/proc/%s/uid_map", pid))
+	if err != nil {
+		return nil, nil, err
+	}
+	gidmap, err := getHostIDMappings(fmt.Sprintf("/proc/%s/gid_map", pid))
+	if err != nil {
+		return nil, nil, err
+	}
+	return uidmap, gidmap, nil
+}
+
+// GetSubIDMappings reads mappings from /etc/subuid and /etc/subgid.
+func GetSubIDMappings(user, group string) ([]specs.LinuxIDMapping, []specs.LinuxIDMapping, error) {
+	mappings, err := idtools.NewIDMappings(user, group)
+	if err != nil {
+		return nil, nil, errors.Wrapf(err, "error reading subuid mappings for user %q and subgid mappings for group %q", user, group)
+	}
+	var uidmap, gidmap []specs.LinuxIDMapping
+	for _, m := range mappings.UIDs() {
+		uidmap = append(uidmap, specs.LinuxIDMapping{
+			ContainerID: uint32(m.ContainerID),
+			HostID:      uint32(m.HostID),
+			Size:        uint32(m.Size),
+		})
+	}
+	for _, m := range mappings.GIDs() {
+		gidmap = append(gidmap, specs.LinuxIDMapping{
+			ContainerID: uint32(m.ContainerID),
+			HostID:      uint32(m.HostID),
+			Size:        uint32(m.Size),
+		})
+	}
+	return uidmap, gidmap, nil
+}
+
+// ParseIDMappings parses mapping triples.
+func ParseIDMappings(uidmap, gidmap []string) ([]idtools.IDMap, []idtools.IDMap, error) {
+	nonDigitsToWhitespace := func(r rune) rune {
+		if strings.IndexRune("0123456789", r) == -1 {
+			return ' '
+		} else {
+			return r
+		}
+	}
+	parseTriple := func(spec []string) (container, host, size uint32, err error) {
+		cid, err := strconv.ParseUint(spec[0], 10, 32)
+		if err != nil {
+			return 0, 0, 0, fmt.Errorf("error parsing id map value %q: %v", spec[0], err)
+		}
+		hid, err := strconv.ParseUint(spec[1], 10, 32)
+		if err != nil {
+			return 0, 0, 0, fmt.Errorf("error parsing id map value %q: %v", spec[1], err)
+		}
+		sz, err := strconv.ParseUint(spec[2], 10, 32)
+		if err != nil {
+			return 0, 0, 0, fmt.Errorf("error parsing id map value %q: %v", spec[2], err)
+		}
+		return uint32(cid), uint32(hid), uint32(sz), nil
+	}
+	parseIDMap := func(mapSpec []string, mapSetting string) (idmap []idtools.IDMap, err error) {
+		for _, idMapSpec := range mapSpec {
+			idSpec := strings.Fields(strings.Map(nonDigitsToWhitespace, idMapSpec))
+			if len(idSpec)%3 != 0 {
+				return nil, errors.Errorf("error initializing ID mappings: %s setting is malformed", mapSetting)
+			}
+			for i := range idSpec {
+				if i%3 != 0 {
+					continue
+				}
+				cid, hid, size, err := parseTriple(idSpec[i : i+3])
+				if err != nil {
+					return nil, errors.Errorf("error initializing ID mappings: %s setting is malformed", mapSetting)
+				}
+				mapping := idtools.IDMap{
+					ContainerID: int(cid),
+					HostID:      int(hid),
+					Size:        int(size),
+				}
+				idmap = append(idmap, mapping)
+			}
+		}
+		return idmap, nil
+	}
+	uid, err := parseIDMap(uidmap, "userns-uid-map")
+	if err != nil {
+		return nil, nil, err
+	}
+	gid, err := parseIDMap(gidmap, "userns-gid-map")
+	if err != nil {
+		return nil, nil, err
+	}
+	return uid, gid, nil
+}
+
+// UnsharedRootPath returns a location under ($XDG_DATA_HOME/containers/storage,
+// or $HOME/.local/share/containers/storage, or
+// (the user's home directory)/.local/share/containers/storage, or an error.
+func UnsharedRootPath(homedir string) (string, error) {
+	// If $XDG_DATA_HOME is defined...
+	if envDataHome, haveDataHome := os.LookupEnv("XDG_DATA_HOME"); haveDataHome {
+		return filepath.Join(envDataHome, "containers", "storage"), nil
+	}
+	// If $XDG_DATA_HOME is not defined, but $HOME is defined...
+	if envHomedir, haveHomedir := os.LookupEnv("HOME"); haveHomedir {
+		// Default to the user's $HOME/.local/share/containers/storage subdirectory.
+		return filepath.Join(envHomedir, ".local", "share", "containers", "storage"), nil
+	}
+	// If we know where our home directory is...
+	if homedir != "" {
+		// Default to the user's homedir/.local/share/containers/storage subdirectory.
+		return filepath.Join(homedir, ".local", "share", "containers", "storage"), nil
+	}
+	return "", errors.New("unable to determine a --root location: neither $XDG_DATA_HOME nor $HOME is set")
+}
+
+// UnsharedRunrootPath returns $XDG_RUNTIME_DIR/run, /var/run/user/(the user's UID)/run, or an error.
+func UnsharedRunrootPath(uid string) (string, error) {
+	// If $XDG_RUNTIME_DIR is defined...
+	if envRuntimeDir, haveRuntimeDir := os.LookupEnv("XDG_RUNTIME_DIR"); haveRuntimeDir {
+		return filepath.Join(envRuntimeDir, "run"), nil
+	}
+	// If $XDG_RUNTIME_DIR is not defined, but we know our UID...
+	if uid != "" {
+		return filepath.Join("/var/run/user", uid, "run"), nil
+	}
+	return "", errors.New("unable to determine a --runroot location: $XDG_RUNTIME_DIR is not set, and we don't know our UID")
+}
+
+// GetPolicyContext sets up, initializes and returns a new context for the specified policy
+func GetPolicyContext(ctx *types.SystemContext) (*signature.PolicyContext, error) {
+	policy, err := signature.DefaultPolicy(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	policyContext, err := signature.NewPolicyContext(policy)
+	if err != nil {
+		return nil, err
+	}
+	return policyContext, nil
+}