distribution/registry/storage/driver/s3-goamz/s3.go

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2014-12-22 22:24:45 +00:00
// Package s3 provides a storagedriver.StorageDriver implementation to
// store blobs in Amazon S3 cloud storage.
//
// This package leverages the docker/goamz client library for interfacing with
// S3. It is intended to be deprecated in favor of the s3-aws driver
// implementation.
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//
// Because S3 is a key, value store the Stat call does not support last modification
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// time for directories (directories are an abstraction for key, value stores)
//
// Keep in mind that S3 guarantees only read-after-write consistency for new
// objects, but no read-after-update or list-after-write consistency.
package s3
import (
"bytes"
"context"
"fmt"
"io"
"io/ioutil"
"net/http"
"reflect"
"strconv"
"strings"
"time"
"github.com/docker/distribution/registry/client/transport"
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/goamz/aws"
"github.com/docker/goamz/s3"
)
const driverName = "s3goamz"
// minChunkSize defines the minimum multipart upload chunk size
// S3 API requires multipart upload chunks to be at least 5MB
const minChunkSize = 5 << 20
const defaultChunkSize = 2 * minChunkSize
// listMax is the largest amount of objects you can request from S3 in a list call
const listMax = 1000
//DriverParameters A struct that encapsulates all of the driver parameters after all values have been set
type DriverParameters struct {
AccessKey string
SecretKey string
Bucket string
Region aws.Region
Encrypt bool
Secure bool
V4Auth bool
ChunkSize int64
RootDirectory string
StorageClass s3.StorageClass
UserAgent string
}
func init() {
factory.Register(driverName, &s3DriverFactory{})
}
// s3DriverFactory implements the factory.StorageDriverFactory interface
type s3DriverFactory struct{}
func (factory *s3DriverFactory) Create(parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
return FromParameters(parameters)
}
type driver struct {
S3 *s3.S3
Bucket *s3.Bucket
ChunkSize int64
Encrypt bool
RootDirectory string
StorageClass s3.StorageClass
}
type baseEmbed struct {
base.Base
}
// Driver is a storagedriver.StorageDriver implementation backed by Amazon S3
// Objects are stored at absolute keys in the provided bucket.
type Driver struct {
baseEmbed
}
// FromParameters constructs a new Driver with a given parameters map
// Required parameters:
// - accesskey
// - secretkey
// - region
// - bucket
// - encrypt
func FromParameters(parameters map[string]interface{}) (*Driver, error) {
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// Providing no values for these is valid in case the user is authenticating
// with an IAM on an ec2 instance (in which case the instance credentials will
// be summoned when GetAuth is called)
accessKey := parameters["accesskey"]
if accessKey == nil {
accessKey = ""
}
secretKey := parameters["secretkey"]
if secretKey == nil {
secretKey = ""
}
regionName := parameters["region"]
if regionName == nil || fmt.Sprint(regionName) == "" {
return nil, fmt.Errorf("No region parameter provided")
}
region := aws.GetRegion(fmt.Sprint(regionName))
if region.Name == "" {
return nil, fmt.Errorf("Invalid region provided: %v", region)
}
bucket := parameters["bucket"]
if bucket == nil || fmt.Sprint(bucket) == "" {
return nil, fmt.Errorf("No bucket parameter provided")
}
encryptBool := false
encrypt := parameters["encrypt"]
switch encrypt := encrypt.(type) {
case string:
b, err := strconv.ParseBool(encrypt)
if err != nil {
return nil, fmt.Errorf("The encrypt parameter should be a boolean")
}
encryptBool = b
case bool:
encryptBool = encrypt
case nil:
// do nothing
default:
return nil, fmt.Errorf("The encrypt parameter should be a boolean")
}
secureBool := true
secure := parameters["secure"]
switch secure := secure.(type) {
case string:
b, err := strconv.ParseBool(secure)
if err != nil {
return nil, fmt.Errorf("The secure parameter should be a boolean")
}
secureBool = b
case bool:
secureBool = secure
case nil:
// do nothing
default:
return nil, fmt.Errorf("The secure parameter should be a boolean")
}
v4AuthBool := false
v4Auth := parameters["v4auth"]
switch v4Auth := v4Auth.(type) {
case string:
b, err := strconv.ParseBool(v4Auth)
if err != nil {
return nil, fmt.Errorf("The v4auth parameter should be a boolean")
}
v4AuthBool = b
case bool:
v4AuthBool = v4Auth
case nil:
// do nothing
default:
return nil, fmt.Errorf("The v4auth parameter should be a boolean")
}
chunkSize := int64(defaultChunkSize)
chunkSizeParam := parameters["chunksize"]
switch v := chunkSizeParam.(type) {
case string:
vv, err := strconv.ParseInt(v, 0, 64)
if err != nil {
return nil, fmt.Errorf("chunksize parameter must be an integer, %v invalid", chunkSizeParam)
}
chunkSize = vv
case int64:
chunkSize = v
case int, uint, int32, uint32, uint64:
chunkSize = reflect.ValueOf(v).Convert(reflect.TypeOf(chunkSize)).Int()
case nil:
// do nothing
default:
return nil, fmt.Errorf("invalid value for chunksize: %#v", chunkSizeParam)
}
if chunkSize < minChunkSize {
return nil, fmt.Errorf("The chunksize %#v parameter should be a number that is larger than or equal to %d", chunkSize, minChunkSize)
}
rootDirectory := parameters["rootdirectory"]
if rootDirectory == nil {
rootDirectory = ""
}
storageClass := s3.StandardStorage
storageClassParam := parameters["storageclass"]
if storageClassParam != nil {
storageClassString, ok := storageClassParam.(string)
if !ok {
return nil, fmt.Errorf("The storageclass parameter must be one of %v, %v invalid", []s3.StorageClass{s3.StandardStorage, s3.ReducedRedundancy}, storageClassParam)
}
// All valid storage class parameters are UPPERCASE, so be a bit more flexible here
storageClassCasted := s3.StorageClass(strings.ToUpper(storageClassString))
if storageClassCasted != s3.StandardStorage && storageClassCasted != s3.ReducedRedundancy {
return nil, fmt.Errorf("The storageclass parameter must be one of %v, %v invalid", []s3.StorageClass{s3.StandardStorage, s3.ReducedRedundancy}, storageClassParam)
}
storageClass = storageClassCasted
}
userAgent := parameters["useragent"]
if userAgent == nil {
userAgent = ""
}
params := DriverParameters{
fmt.Sprint(accessKey),
fmt.Sprint(secretKey),
fmt.Sprint(bucket),
region,
encryptBool,
secureBool,
v4AuthBool,
chunkSize,
fmt.Sprint(rootDirectory),
storageClass,
fmt.Sprint(userAgent),
}
return New(params)
}
// New constructs a new Driver with the given AWS credentials, region, encryption flag, and
// bucketName
func New(params DriverParameters) (*Driver, error) {
auth, err := aws.GetAuth(params.AccessKey, params.SecretKey, "", time.Time{})
if err != nil {
return nil, fmt.Errorf("unable to resolve aws credentials, please ensure that 'accesskey' and 'secretkey' are properly set or the credentials are available in $HOME/.aws/credentials: %v", err)
}
if !params.Secure {
params.Region.S3Endpoint = strings.Replace(params.Region.S3Endpoint, "https", "http", 1)
}
s3obj := s3.New(auth, params.Region)
if params.UserAgent != "" {
s3obj.Client = &http.Client{
Transport: transport.NewTransport(http.DefaultTransport,
transport.NewHeaderRequestModifier(http.Header{
http.CanonicalHeaderKey("User-Agent"): []string{params.UserAgent},
}),
),
}
}
if params.V4Auth {
s3obj.Signature = aws.V4Signature
} else if mustV4Auth(params.Region.Name) {
return nil, fmt.Errorf("The %s region only works with v4 authentication", params.Region.Name)
}
bucket := s3obj.Bucket(params.Bucket)
// TODO Currently multipart uploads have no timestamps, so this would be unwise
// if you initiated a new s3driver while another one is running on the same bucket.
// multis, _, err := bucket.ListMulti("", "")
// if err != nil {
// return nil, err
// }
// for _, multi := range multis {
// err := multi.Abort()
// //TODO appropriate to do this error checking?
// if err != nil {
// return nil, err
// }
// }
d := &driver{
S3: s3obj,
Bucket: bucket,
ChunkSize: params.ChunkSize,
Encrypt: params.Encrypt,
RootDirectory: params.RootDirectory,
StorageClass: params.StorageClass,
}
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.Bucket.Get(d.s3Path(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 {
return parseError(path, d.Bucket.Put(d.s3Path(path), contents, d.getContentType(), getPermissions(), d.getOptions()))
}
// Reader retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *driver) Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
headers := make(http.Header)
headers.Add("Range", "bytes="+strconv.FormatInt(offset, 10)+"-")
resp, err := d.Bucket.GetResponseWithHeaders(d.s3Path(path), headers)
if err != nil {
if s3Err, ok := err.(*s3.Error); ok && s3Err.Code == "InvalidRange" {
return ioutil.NopCloser(bytes.NewReader(nil)), nil
}
return nil, parseError(path, err)
}
return resp.Body, nil
}
// Writer returns a FileWriter which will store the content written to it
// at the location designated by "path" after the call to Commit.
func (d *driver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
key := d.s3Path(path)
if !append {
// TODO (brianbland): cancel other uploads at this path
multi, err := d.Bucket.InitMulti(key, d.getContentType(), getPermissions(), d.getOptions())
if err != nil {
return nil, err
}
return d.newWriter(key, multi, nil), nil
}
multis, _, err := d.Bucket.ListMulti(key, "")
if err != nil {
return nil, parseError(path, err)
}
for _, multi := range multis {
if key != multi.Key {
continue
}
parts, err := multi.ListParts()
if err != nil {
return nil, parseError(path, err)
}
var multiSize int64
for _, part := range parts {
multiSize += part.Size
}
return d.newWriter(key, multi, parts), nil
}
return nil, storagedriver.PathNotFoundError{Path: path}
}
// 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) {
listResponse, err := d.Bucket.List(d.s3Path(path), "", "", 1)
if err != nil {
return nil, err
}
fi := storagedriver.FileInfoFields{
Path: path,
}
if len(listResponse.Contents) == 1 {
if listResponse.Contents[0].Key != d.s3Path(path) {
fi.IsDir = true
} else {
fi.IsDir = false
fi.Size = listResponse.Contents[0].Size
timestamp, err := time.Parse(time.RFC3339Nano, listResponse.Contents[0].LastModified)
if err != nil {
return nil, err
}
fi.ModTime = timestamp
}
} else if len(listResponse.CommonPrefixes) == 1 {
fi.IsDir = true
} else {
return nil, storagedriver.PathNotFoundError{Path: path}
}
return storagedriver.FileInfoInternal{FileInfoFields: fi}, nil
}
// List returns a list of the objects that are direct descendants of the given path.
func (d *driver) List(ctx context.Context, opath string) ([]string, error) {
path := opath
if path != "/" && path[len(path)-1] != '/' {
path = path + "/"
}
// This is to cover for the cases when the rootDirectory of the driver is either "" or "/".
// In those cases, there is no root prefix to replace and we must actually add a "/" to all
// results in order to keep them as valid paths as recognized by storagedriver.PathRegexp
prefix := ""
if d.s3Path("") == "" {
prefix = "/"
}
listResponse, err := d.Bucket.List(d.s3Path(path), "/", "", listMax)
if err != nil {
return nil, parseError(opath, err)
}
files := []string{}
directories := []string{}
for {
for _, key := range listResponse.Contents {
files = append(files, strings.Replace(key.Key, d.s3Path(""), prefix, 1))
}
for _, commonPrefix := range listResponse.CommonPrefixes {
directories = append(directories, strings.Replace(commonPrefix[0:len(commonPrefix)-1], d.s3Path(""), prefix, 1))
}
if !listResponse.IsTruncated {
break
}
listResponse, err = d.Bucket.List(d.s3Path(path), "/", listResponse.NextMarker, listMax)
if err != nil {
return nil, err
}
}
if opath != "/" {
if len(files) == 0 && len(directories) == 0 {
// Treat empty response as missing directory, since we don't actually
// have directories in s3.
return nil, storagedriver.PathNotFoundError{Path: opath}
}
}
return append(files, directories...), nil
}
// 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 {
/* This is terrible, but aws doesn't have an actual move. */
_, err := d.Bucket.PutCopy(d.s3Path(destPath), getPermissions(),
s3.CopyOptions{Options: d.getOptions(), ContentType: d.getContentType()}, d.Bucket.Name+"/"+d.s3Path(sourcePath))
if err != nil {
return parseError(sourcePath, err)
}
return d.Delete(ctx, sourcePath)
}
// Delete recursively deletes all objects stored at "path" and its subpaths.
func (d *driver) Delete(ctx context.Context, path string) error {
s3Path := d.s3Path(path)
listResponse, err := d.Bucket.List(s3Path, "", "", listMax)
if err != nil || len(listResponse.Contents) == 0 {
return storagedriver.PathNotFoundError{Path: path}
}
s3Objects := make([]s3.Object, listMax)
for len(listResponse.Contents) > 0 {
numS3Objects := len(listResponse.Contents)
for index, key := range listResponse.Contents {
// Stop if we encounter a key that is not a subpath (so that deleting "/a" does not delete "/ab").
if len(key.Key) > len(s3Path) && (key.Key)[len(s3Path)] != '/' {
numS3Objects = index
break
}
s3Objects[index].Key = key.Key
}
err := d.Bucket.DelMulti(s3.Delete{Quiet: false, Objects: s3Objects[0:numS3Objects]})
if err != nil {
return nil
}
if numS3Objects < len(listResponse.Contents) {
return nil
}
listResponse, err = d.Bucket.List(d.s3Path(path), "", "", listMax)
if err != nil {
return err
}
}
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) {
methodString := "GET"
method, ok := options["method"]
if ok {
methodString, ok = method.(string)
if !ok || (methodString != "GET" && methodString != "HEAD") {
return "", storagedriver.ErrUnsupportedMethod{}
}
}
expiresTime := time.Now().Add(20 * time.Minute)
expires, ok := options["expiry"]
if ok {
et, ok := expires.(time.Time)
if ok {
expiresTime = et
}
}
return d.Bucket.SignedURLWithMethod(methodString, d.s3Path(path), expiresTime, nil, nil), nil
}
func (d *driver) s3Path(path string) string {
return strings.TrimLeft(strings.TrimRight(d.RootDirectory, "/")+path, "/")
}
// S3BucketKey returns the s3 bucket key for the given storage driver path.
func (d *Driver) S3BucketKey(path string) string {
return d.StorageDriver.(*driver).s3Path(path)
}
// Walk traverses a filesystem defined within driver, starting
// from the given path, calling f on each file
func (d *driver) Walk(ctx context.Context, path string, f storagedriver.WalkFn) error {
return storagedriver.WalkFallback(ctx, d, path, f)
}
func parseError(path string, err error) error {
if s3Err, ok := err.(*s3.Error); ok && s3Err.Code == "NoSuchKey" {
return storagedriver.PathNotFoundError{Path: path}
}
return err
}
func (d *driver) getOptions() s3.Options {
return s3.Options{
SSE: d.Encrypt,
StorageClass: d.StorageClass,
}
}
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func getPermissions() s3.ACL {
return s3.Private
}
// mustV4Auth checks whether must use v4 auth in specific region.
// Please see documentation at http://docs.aws.amazon.com/general/latest/gr/signature-version-2.html
func mustV4Auth(region string) bool {
switch region {
case "eu-central-1", "cn-north-1", "us-east-2",
"ca-central-1", "ap-south-1", "ap-northeast-2", "eu-west-2":
return true
}
return false
}
func (d *driver) getContentType() string {
return "application/octet-stream"
}
// writer attempts to upload parts to S3 in a buffered fashion where the last
// part is at least as large as the chunksize, so the multipart upload could be
// cleanly resumed in the future. This is violated if Close is called after less
// than a full chunk is written.
type writer struct {
driver *driver
key string
multi *s3.Multi
parts []s3.Part
size int64
readyPart []byte
pendingPart []byte
closed bool
committed bool
cancelled bool
}
func (d *driver) newWriter(key string, multi *s3.Multi, parts []s3.Part) storagedriver.FileWriter {
var size int64
for _, part := range parts {
size += part.Size
}
return &writer{
driver: d,
key: key,
multi: multi,
parts: parts,
size: size,
}
}
func (w *writer) Write(p []byte) (int, error) {
if w.closed {
return 0, fmt.Errorf("already closed")
} else if w.committed {
return 0, fmt.Errorf("already committed")
} else if w.cancelled {
return 0, fmt.Errorf("already cancelled")
}
// If the last written part is smaller than minChunkSize, we need to make a
// new multipart upload :sadface:
if len(w.parts) > 0 && int(w.parts[len(w.parts)-1].Size) < minChunkSize {
err := w.multi.Complete(w.parts)
if err != nil {
w.multi.Abort()
return 0, err
}
multi, err := w.driver.Bucket.InitMulti(w.key, w.driver.getContentType(), getPermissions(), w.driver.getOptions())
if err != nil {
return 0, err
}
w.multi = multi
// If the entire written file is smaller than minChunkSize, we need to make
// a new part from scratch :double sad face:
if w.size < minChunkSize {
contents, err := w.driver.Bucket.Get(w.key)
if err != nil {
return 0, err
}
w.parts = nil
w.readyPart = contents
} else {
// Otherwise we can use the old file as the new first part
_, part, err := multi.PutPartCopy(1, s3.CopyOptions{}, w.driver.Bucket.Name+"/"+w.key)
if err != nil {
return 0, err
}
w.parts = []s3.Part{part}
}
}
var n int
for len(p) > 0 {
// If no parts are ready to write, fill up the first part
if neededBytes := int(w.driver.ChunkSize) - len(w.readyPart); neededBytes > 0 {
if len(p) >= neededBytes {
w.readyPart = append(w.readyPart, p[:neededBytes]...)
n += neededBytes
p = p[neededBytes:]
} else {
w.readyPart = append(w.readyPart, p...)
n += len(p)
p = nil
}
}
if neededBytes := int(w.driver.ChunkSize) - len(w.pendingPart); neededBytes > 0 {
if len(p) >= neededBytes {
w.pendingPart = append(w.pendingPart, p[:neededBytes]...)
n += neededBytes
p = p[neededBytes:]
err := w.flushPart()
if err != nil {
w.size += int64(n)
return n, err
}
} else {
w.pendingPart = append(w.pendingPart, p...)
n += len(p)
p = nil
}
}
}
w.size += int64(n)
return n, nil
}
func (w *writer) Size() int64 {
return w.size
}
func (w *writer) Close() error {
if w.closed {
return fmt.Errorf("already closed")
}
w.closed = true
return w.flushPart()
}
func (w *writer) Cancel() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
}
w.cancelled = true
err := w.multi.Abort()
return err
}
func (w *writer) Commit() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
} else if w.cancelled {
return fmt.Errorf("already cancelled")
}
err := w.flushPart()
if err != nil {
return err
}
w.committed = true
err = w.multi.Complete(w.parts)
if err != nil {
w.multi.Abort()
return err
}
return nil
}
// flushPart flushes buffers to write a part to S3.
// Only called by Write (with both buffers full) and Close/Commit (always)
func (w *writer) flushPart() error {
if len(w.readyPart) == 0 && len(w.pendingPart) == 0 {
// nothing to write
return nil
}
if len(w.pendingPart) < int(w.driver.ChunkSize) {
// closing with a small pending part
// combine ready and pending to avoid writing a small part
w.readyPart = append(w.readyPart, w.pendingPart...)
w.pendingPart = nil
}
part, err := w.multi.PutPart(len(w.parts)+1, bytes.NewReader(w.readyPart))
if err != nil {
return err
}
w.parts = append(w.parts, part)
w.readyPart = w.pendingPart
w.pendingPart = nil
return nil
}