distribution/registry/storage/driver/swift/swift.go

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// Package swift provides a storagedriver.StorageDriver implementation to
// store blobs in Openstack Swift object storage.
//
// This package leverages the ncw/swift client library for interfacing with
// Swift.
//
// It supports both TempAuth authentication and Keystone authentication
// (up to version 3).
//
// Since Swift has no concept of directories (directories are an abstration),
// empty objects are created with the MIME type application/vnd.swift.directory.
//
// As Swift has a limit on the size of a single uploaded object (by default
// this is 5GB), the driver makes use of the Swift Large Object Support
// (http://docs.openstack.org/developer/swift/overview_large_objects.html).
// Only one container is used for both manifests and data objects. Manifests
// are stored in the 'files' pseudo directory, data objects are stored under
// 'segments'.
package swift
import (
"bytes"
"crypto/tls"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net/http"
gopath "path"
"strconv"
"strings"
"time"
"github.com/mitchellh/mapstructure"
"github.com/ncw/swift"
"github.com/docker/distribution/context"
storagedriver "github.com/docker/distribution/registry/storage/driver"
"github.com/docker/distribution/registry/storage/driver/base"
"github.com/docker/distribution/registry/storage/driver/factory"
"github.com/docker/distribution/version"
)
const driverName = "swift"
// defaultChunkSize defines the default size of a segment
const defaultChunkSize = 20 * 1024 * 1024
// minChunkSize defines the minimum size of a segment
const minChunkSize = 1 << 20
// Parameters A struct that encapsulates all of the driver parameters after all values have been set
type Parameters struct {
Username string
Password string
AuthURL string
Tenant string
TenantID string
Domain string
DomainID string
Region string
Container string
Prefix string
InsecureSkipVerify bool
ChunkSize int
}
type swiftInfo map[string]interface{}
func init() {
factory.Register(driverName, &swiftDriverFactory{})
}
// swiftDriverFactory implements the factory.StorageDriverFactory interface
type swiftDriverFactory struct{}
func (factory *swiftDriverFactory) Create(parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
return FromParameters(parameters)
}
type driver struct {
Conn swift.Connection
Container string
Prefix string
BulkDeleteSupport bool
ChunkSize int
}
type baseEmbed struct {
base.Base
}
// Driver is a storagedriver.StorageDriver implementation backed by Openstack Swift
// Objects are stored at absolute keys in the provided container.
type Driver struct {
baseEmbed
}
// FromParameters constructs a new Driver with a given parameters map
// Required parameters:
// - username
// - password
// - authurl
// - container
func FromParameters(parameters map[string]interface{}) (*Driver, error) {
params := Parameters{
ChunkSize: defaultChunkSize,
InsecureSkipVerify: false,
}
if err := mapstructure.Decode(parameters, &params); err != nil {
return nil, err
}
if params.Username == "" {
return nil, fmt.Errorf("No username parameter provided")
}
if params.Password == "" {
return nil, fmt.Errorf("No password parameter provided")
}
if params.AuthURL == "" {
return nil, fmt.Errorf("No authurl parameter provided")
}
if params.Container == "" {
return nil, fmt.Errorf("No container parameter provided")
}
if params.ChunkSize < minChunkSize {
return nil, fmt.Errorf("The chunksize %#v parameter should be a number that is larger than or equal to %d", params.ChunkSize, minChunkSize)
}
return New(params)
}
// New constructs a new Driver with the given Openstack Swift credentials and container name
func New(params Parameters) (*Driver, error) {
transport := &http.Transport{
Proxy: http.ProxyFromEnvironment,
MaxIdleConnsPerHost: 2048,
TLSClientConfig: &tls.Config{InsecureSkipVerify: params.InsecureSkipVerify},
}
ct := swift.Connection{
UserName: params.Username,
ApiKey: params.Password,
AuthUrl: params.AuthURL,
Region: params.Region,
UserAgent: "distribution/" + version.Version,
Tenant: params.Tenant,
TenantId: params.TenantID,
Domain: params.Domain,
DomainId: params.DomainID,
Transport: transport,
ConnectTimeout: 60 * time.Second,
Timeout: 15 * 60 * time.Second,
}
err := ct.Authenticate()
if err != nil {
return nil, fmt.Errorf("Swift authentication failed: %s", err)
}
if err := ct.ContainerCreate(params.Container, nil); err != nil {
return nil, fmt.Errorf("Failed to create container %s (%s)", params.Container, err)
}
d := &driver{
Conn: ct,
Container: params.Container,
Prefix: params.Prefix,
BulkDeleteSupport: detectBulkDelete(params.AuthURL),
ChunkSize: params.ChunkSize,
}
return &Driver{
baseEmbed: baseEmbed{
Base: base.Base{
StorageDriver: d,
},
},
}, nil
}
// Implement the storagedriver.StorageDriver interface
func (d *driver) Name() string {
return driverName
}
// GetContent retrieves the content stored at "path" as a []byte.
func (d *driver) GetContent(ctx context.Context, path string) ([]byte, error) {
content, err := d.Conn.ObjectGetBytes(d.Container, d.swiftPath(path))
if err != nil {
return nil, parseError(path, err)
}
return content, nil
}
// PutContent stores the []byte content at a location designated by "path".
func (d *driver) PutContent(ctx context.Context, path string, contents []byte) error {
err := d.Conn.ObjectPutBytes(d.Container, d.swiftPath(path),
contents, d.getContentType())
return parseError(path, err)
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
headers := make(swift.Headers)
headers["Range"] = "bytes=" + strconv.FormatInt(offset, 10) + "-"
file, _, err := d.Conn.ObjectOpen(d.Container, d.swiftPath(path), false, headers)
if err != nil {
if swiftErr, ok := err.(*swift.Error); ok && swiftErr.StatusCode == http.StatusRequestedRangeNotSatisfiable {
return ioutil.NopCloser(bytes.NewReader(nil)), nil
}
return nil, parseError(path, err)
}
return file, nil
}
// WriteStream stores the contents of the provided io.Reader at a
// location designated by the given path. The driver will know it has
// received the full contents when the reader returns io.EOF. The number
// of successfully READ bytes will be returned, even if an error is
// returned. May be used to resume writing a stream by providing a nonzero
// offset. Offsets past the current size will write from the position
// beyond the end of the file.
func (d *driver) WriteStream(ctx context.Context, path string, offset int64, reader io.Reader) (int64, error) {
var (
segments []swift.Object
multi io.Reader
paddingReader io.Reader
currentLength int64
cursor int64
)
partNumber := 1
chunkSize := int64(d.ChunkSize)
zeroBuf := make([]byte, d.ChunkSize)
getSegment := func() string {
return fmt.Sprintf("%s/%016d", d.swiftSegmentPath(path), partNumber)
}
max := func(a int64, b int64) int64 {
if a > b {
return a
}
return b
}
info, _, err := d.Conn.Object(d.Container, d.swiftPath(path))
if err != nil {
if err == swift.ContainerNotFound || err == swift.ObjectNotFound {
// Create a object manifest
manifest, err := d.createManifest(path)
if err != nil {
return 0, parseError(path, err)
}
manifest.Close()
} else {
return 0, parseError(path, err)
}
} else {
// The manifest already exists. Get all the segments
currentLength = info.Bytes
segments, err = d.getAllSegments(path)
if err != nil {
return 0, parseError(path, err)
}
}
// First, we skip the existing segments that are not modified by this call
for i := range segments {
if offset < cursor+segments[i].Bytes {
break
}
cursor += segments[i].Bytes
partNumber++
}
// We reached the end of the file but we haven't reached 'offset' yet
// Therefore we add blocks of zeros
if offset >= currentLength {
for offset-currentLength >= chunkSize {
// Insert a block a zero
d.Conn.ObjectPut(d.Container, getSegment(),
bytes.NewReader(zeroBuf), false, "",
d.getContentType(), nil)
currentLength += chunkSize
partNumber++
}
cursor = currentLength
paddingReader = bytes.NewReader(zeroBuf)
} else if offset-cursor > 0 {
// Offset is inside the current segment : we need to read the
// data from the beginning of the segment to offset
file, _, err := d.Conn.ObjectOpen(d.Container, getSegment(), false, nil)
if err != nil {
return 0, parseError(getSegment(), err)
}
defer file.Close()
paddingReader = file
}
readers := []io.Reader{}
if paddingReader != nil {
readers = append(readers, io.LimitReader(paddingReader, offset-cursor))
}
readers = append(readers, io.LimitReader(reader, chunkSize-(offset-cursor)))
multi = io.MultiReader(readers...)
writeSegment := func(segment string) (finished bool, bytesRead int64, err error) {
currentSegment, err := d.Conn.ObjectCreate(d.Container, segment, false, "", d.getContentType(), nil)
if err != nil {
return false, bytesRead, parseError(path, err)
}
n, err := io.Copy(currentSegment, multi)
if err != nil {
return false, bytesRead, parseError(path, err)
}
if n > 0 {
defer currentSegment.Close()
bytesRead += n - max(0, offset-cursor)
}
if n < chunkSize {
// We wrote all the data
if cursor+n < currentLength {
// Copy the end of the chunk
headers := make(swift.Headers)
headers["Range"] = "bytes=" + strconv.FormatInt(cursor+n, 10) + "-" + strconv.FormatInt(cursor+chunkSize, 10)
file, _, err := d.Conn.ObjectOpen(d.Container, d.swiftPath(path), false, headers)
if err != nil {
return false, bytesRead, parseError(path, err)
}
_, copyErr := io.Copy(currentSegment, file)
if err := file.Close(); err != nil {
return false, bytesRead, parseError(path, err)
}
if copyErr != nil {
return false, bytesRead, parseError(path, copyErr)
}
}
return true, bytesRead, nil
}
multi = io.LimitReader(reader, chunkSize)
cursor += chunkSize
partNumber++
return false, bytesRead, nil
}
finished := false
read := int64(0)
bytesRead := int64(0)
for finished == false {
finished, read, err = writeSegment(getSegment())
bytesRead += read
if err != nil {
return bytesRead, err
}
}
return bytesRead, nil
}
// Stat retrieves the FileInfo for the given path, including the current size
// in bytes and the creation time.
func (d *driver) Stat(ctx context.Context, path string) (storagedriver.FileInfo, error) {
swiftPath := d.swiftPath(path)
opts := &swift.ObjectsOpts{
Prefix: swiftPath,
Delimiter: '/',
}
objects, err := d.Conn.ObjectsAll(d.Container, opts)
if err != nil {
return nil, err
}
fi := storagedriver.FileInfoFields{
Path: strings.TrimPrefix(strings.TrimSuffix(swiftPath, "/"), d.swiftPath("/")),
}
for _, obj := range objects {
if obj.PseudoDirectory && obj.Name == swiftPath+"/" {
fi.IsDir = true
return storagedriver.FileInfoInternal{FileInfoFields: fi}, nil
} else if obj.Name == swiftPath {
// On Swift 1.12, the 'bytes' field is always 0
// so we need to do a second HEAD request
info, _, err := d.Conn.Object(d.Container, swiftPath)
if err != nil {
return nil, parseError(path, err)
}
fi.IsDir = false
fi.Size = info.Bytes
fi.ModTime = info.LastModified
return storagedriver.FileInfoInternal{FileInfoFields: fi}, nil
}
}
return nil, storagedriver.PathNotFoundError{Path: path}
}
// List returns a list of the objects that are direct descendants of the given path.
func (d *driver) List(ctx context.Context, path string) ([]string, error) {
var files []string
prefix := d.swiftPath(path)
if prefix != "" {
prefix += "/"
}
opts := &swift.ObjectsOpts{
Prefix: prefix,
Delimiter: '/',
}
objects, err := d.Conn.Objects(d.Container, opts)
for _, obj := range objects {
files = append(files, strings.TrimPrefix(strings.TrimSuffix(obj.Name, "/"), d.swiftPath("/")))
}
return files, parseError(path, err)
}
// Move moves an object stored at sourcePath to destPath, removing the original
// object.
func (d *driver) Move(ctx context.Context, sourcePath string, destPath string) error {
err := d.Conn.ObjectMove(d.Container, d.swiftPath(sourcePath),
d.Container, d.swiftPath(destPath))
if err != nil {
return parseError(sourcePath, err)
}
return nil
}
// Delete recursively deletes all objects stored at "path" and its subpaths.
func (d *driver) Delete(ctx context.Context, path string) error {
opts := swift.ObjectsOpts{
Prefix: d.swiftPath(path) + "/",
}
objects, err := d.Conn.Objects(d.Container, &opts)
if err != nil {
return parseError(path, err)
}
if d.BulkDeleteSupport {
filenames := make([]string, len(objects))
for i, obj := range objects {
filenames[i] = obj.Name
}
if _, err := d.Conn.BulkDelete(d.Container, filenames); err != swift.Forbidden {
return parseError(path, err)
}
}
for _, obj := range objects {
if obj.PseudoDirectory {
continue
}
if _, headers, err := d.Conn.Object(d.Container, obj.Name); err == nil {
manifest, ok := headers["X-Object-Manifest"]
if ok {
components := strings.SplitN(manifest, "/", 2)
segContainer := components[0]
segments, err := d.getAllSegments(components[1])
if err != nil {
return parseError(obj.Name, err)
}
for _, s := range segments {
if err := d.Conn.ObjectDelete(segContainer, s.Name); err != nil {
return parseError(s.Name, err)
}
}
}
} else {
return parseError(obj.Name, err)
}
if err := d.Conn.ObjectDelete(d.Container, obj.Name); err != nil {
return parseError(obj.Name, err)
}
}
if _, err := d.Stat(ctx, path); err == nil {
return parseError(path, d.Conn.ObjectDelete(d.Container, d.swiftPath(path)))
} else if len(objects) == 0 {
return storagedriver.PathNotFoundError{Path: path}
}
return nil
}
// URLFor returns a URL which may be used to retrieve the content stored at the given path.
// May return an UnsupportedMethodErr in certain StorageDriver implementations.
func (d *driver) URLFor(ctx context.Context, path string, options map[string]interface{}) (string, error) {
return "", storagedriver.ErrUnsupportedMethod
}
func (d *driver) swiftPath(path string) string {
return strings.TrimLeft(strings.TrimRight(d.Prefix+"/files"+path, "/"), "/")
}
func (d *driver) swiftSegmentPath(path string) string {
return strings.TrimLeft(strings.TrimRight(d.Prefix+"/segments"+path, "/"), "/")
}
func (d *driver) getContentType() string {
return "application/octet-stream"
}
func (d *driver) getAllSegments(path string) ([]swift.Object, error) {
return d.Conn.Objects(d.Container, &swift.ObjectsOpts{Prefix: d.swiftSegmentPath(path)})
}
func (d *driver) createManifest(path string) (*swift.ObjectCreateFile, error) {
headers := make(swift.Headers)
headers["X-Object-Manifest"] = d.Container + "/" + d.swiftSegmentPath(path)
return d.Conn.ObjectCreate(d.Container, d.swiftPath(path), false, "",
d.getContentType(), headers)
}
func detectBulkDelete(authURL string) (bulkDelete bool) {
resp, err := http.Get(gopath.Join(authURL, "..", "..") + "/info")
if err == nil {
defer resp.Body.Close()
decoder := json.NewDecoder(resp.Body)
var infos swiftInfo
if decoder.Decode(&infos) == nil {
_, bulkDelete = infos["bulk_delete"]
}
}
return
}
func parseError(path string, err error) error {
if err == swift.ContainerNotFound || err == swift.ObjectNotFound {
return storagedriver.PathNotFoundError{Path: path}
}
return err
}