Merge pull request #864 from AndreyKostov/next-generation

S3 storage driver for next gen modifications

storagedriver/s3/s3.go

@@ -1,13 +1,28 @@
-// +build ignore
-
+// Package s3 provides a storagedriver.StorageDriver implementation to
+// store blobs in Amazon S3 cloud storage.
+//
+// This package leverages the crowdmob/goamz client library for interfacing with
+// s3.
+//
+// Because s3 is a key, value store the Stat call does not support last modification
+// time for directories (directories are an abstraction for key, value stores)
+//
+// Keep in mind that s3 guarantees only eventual consistency, so do not assume
+// that a successful write will mean immediate access to the data written (although
+// in most regions a new object put has guaranteed read after write). The only true
+// guarantee is that once you call Stat and receive a certain file size, that much of
+// the file is already accessible.
 package s3
 
 import (
 	"bytes"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"strconv"
+	"strings"
+	"time"
 
 	"github.com/crowdmob/goamz/aws"
 	"github.com/crowdmob/goamz/s3"
@@ -19,10 +34,10 @@ const driverName = "s3"
 
 // minChunkSize defines the minimum multipart upload chunk size
 // S3 API requires multipart upload chunks to be at least 5MB
-const minChunkSize = 5 * 1024 * 1024
+const chunkSize = 5 * 1024 * 1024
 
-// listPartsMax is the largest amount of parts you can request from S3
-const listPartsMax = 1000
+// listMax is the largest amount of objects you can request from S3 in a list call
+const listMax = 1000
 
 func init() {
 	factory.Register(driverName, &s3DriverFactory{})
@@ -31,7 +46,7 @@ func init() {
 // s3DriverFactory implements the factory.StorageDriverFactory interface
 type s3DriverFactory struct{}
 
-func (factory *s3DriverFactory) Create(parameters map[string]string) (storagedriver.StorageDriver, error) {
+func (factory *s3DriverFactory) Create(parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
 	return FromParameters(parameters)
 }
 
@@ -41,6 +56,7 @@ type Driver struct {
 	S3            *s3.S3
 	Bucket        *s3.Bucket
 	Encrypt       bool
+	rootDirectory string
 }
 
 // FromParameters constructs a new Driver with a given parameters map
@@ -50,28 +66,24 @@ type Driver struct {
 // - region
 // - bucket
 // - encrypt
-func FromParameters(parameters map[string]string) (*Driver, error) {
-	accessKey, ok := parameters["accesskey"]
-	if !ok || accessKey == "" {
-		return nil, fmt.Errorf("No accesskey parameter provided")
-	}
-
-	secretKey, ok := parameters["secretkey"]
-	if !ok || secretKey == "" {
-		return nil, fmt.Errorf("No secretkey parameter provided")
-	}
+func FromParameters(parameters map[string]interface{}) (*Driver, error) {
+	// 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"]
+	secretKey, _ := parameters["secretkey"]
 
 	regionName, ok := parameters["region"]
-	if !ok || regionName == "" {
+	if !ok || regionName.(string) == "" {
 		return nil, fmt.Errorf("No region parameter provided")
 	}
-	region := aws.GetRegion(regionName)
+	region := aws.GetRegion(fmt.Sprint(regionName))
 	if region.Name == "" {
 		return nil, fmt.Errorf("Invalid region provided: %v", region)
 	}
 
 	bucket, ok := parameters["bucket"]
-	if !ok || bucket == "" {
+	if !ok || fmt.Sprint(bucket) == "" {
 		return nil, fmt.Errorf("No bucket parameter provided")
 	}
 
@@ -80,136 +92,415 @@ func FromParameters(parameters map[string]string) (*Driver, error) {
 		return nil, fmt.Errorf("No encrypt parameter provided")
 	}
 
-	encryptBool, err := strconv.ParseBool(encrypt)
-	if err != nil {
-		return nil, fmt.Errorf("Unable to parse the encrypt parameter: %v", err)
+	encryptBool, ok := encrypt.(bool)
+	if !ok {
+		return nil, fmt.Errorf("The encrypt parameter should be a boolean")
 	}
-	return New(accessKey, secretKey, region, encryptBool, bucket)
+
+	rootDirectory, ok := parameters["rootdirectory"]
+	if !ok {
+		return nil, fmt.Errorf("No rootdirectory parameter provided")
+	}
+
+	return New(fmt.Sprint(accessKey), fmt.Sprint(secretKey), fmt.Sprint(bucket), fmt.Sprint(rootDirectory), region, encryptBool)
 }
 
 // New constructs a new Driver with the given AWS credentials, region, encryption flag, and
 // bucketName
-func New(accessKey string, secretKey string, region aws.Region, encrypt bool, bucketName string) (*Driver, error) {
-	auth := aws.Auth{AccessKey: accessKey, SecretKey: secretKey}
+func New(accessKey, secretKey, bucketName, rootDirectory string, region aws.Region, encrypt bool) (*Driver, error) {
+	auth, err := aws.GetAuth(accessKey, secretKey, "", time.Time{})
+	if err != nil {
+		return nil, err
+	}
+
 	s3obj := s3.New(auth, region)
 	bucket := s3obj.Bucket(bucketName)
 
-	if err := bucket.PutBucket(getPermissions()); err != nil {
-		s3Err, ok := err.(*s3.Error)
-		if !(ok && s3Err.Code == "BucketAlreadyOwnedByYou") {
+	if _, err := bucket.List("", "", "", 1); err != nil {
 		return nil, err
 	}
-	}
 
-	return &Driver{s3obj, bucket, encrypt}, nil
+	// 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
+	// 	}
+	// }
+
+	return &Driver{s3obj, bucket, encrypt, rootDirectory}, nil
 }
 
 // Implement the storagedriver.StorageDriver interface
 
 // GetContent retrieves the content stored at "path" as a []byte.
 func (d *Driver) GetContent(path string) ([]byte, error) {
-	content, err := d.Bucket.Get(path)
+	if !storagedriver.PathRegexp.MatchString(path) {
+		return nil, storagedriver.InvalidPathError{Path: path}
+	}
+
+	content, err := d.Bucket.Get(d.s3Path(path))
 	if err != nil {
-		return nil, storagedriver.PathNotFoundError{Path: path}
+		return nil, parseError(path, err)
 	}
 	return content, nil
 }
 
 // PutContent stores the []byte content at a location designated by "path".
 func (d *Driver) PutContent(path string, contents []byte) error {
-	return d.Bucket.Put(path, contents, d.getContentType(), getPermissions(), d.getOptions())
+	if !storagedriver.PathRegexp.MatchString(path) {
+		return storagedriver.InvalidPathError{Path: path}
+	}
+
+	return parseError(path, d.Bucket.Put(d.s3Path(path), contents, d.getContentType(), getPermissions(), d.getOptions()))
 }
 
 // ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
 // given byte offset.
 func (d *Driver) ReadStream(path string, offset int64) (io.ReadCloser, error) {
+	if !storagedriver.PathRegexp.MatchString(path) {
+		return nil, storagedriver.InvalidPathError{Path: path}
+	}
+
+	if offset < 0 {
+		return nil, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
+	}
+
 	headers := make(http.Header)
 	headers.Add("Range", "bytes="+strconv.FormatInt(offset, 10)+"-")
 
-	resp, err := d.Bucket.GetResponseWithHeaders(path, headers)
+	resp, err := d.Bucket.GetResponseWithHeaders(d.s3Path(path), headers)
 	if err != nil {
-		return nil, storagedriver.PathNotFoundError{Path: path}
+		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
 }
 
-// WriteStream stores the contents of the provided io.ReadCloser at a location
-// designated by the given path.
-func (d *Driver) WriteStream(path string, offset, size int64, reader io.ReadCloser) error {
-	defer reader.Close()
+// 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(path string, offset int64, reader io.Reader) (totalRead int64, err error) {
+	if !storagedriver.PathRegexp.MatchString(path) {
+		return 0, storagedriver.InvalidPathError{Path: path}
+	}
 
-	chunkSize := int64(minChunkSize)
-	for size/chunkSize >= listPartsMax {
-		chunkSize *= 2
+	if offset < 0 {
+		return 0, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
 	}
 
 	partNumber := 1
-	var totalRead int64
-	multi, parts, err := d.getAllParts(path)
+	bytesRead := 0
+	parts := []s3.Part{}
+	var part s3.Part
+
+	multi, err := d.Bucket.InitMulti(d.s3Path(path), d.getContentType(), getPermissions(), d.getOptions())
+	if err != nil {
+		return 0, err
+	}
+
+	buf := make([]byte, chunkSize)
+	zeroBuf := make([]byte, chunkSize)
+
+	// We never want to leave a dangling multipart upload, our only consistent state is
+	// when there is a whole object at path. This is in order to remain consistent with
+	// the stat call.
+	//
+	// Note that if the machine dies before executing the defer, we will be left with a dangling
+	// multipart upload, which will eventually be cleaned up, but we will lose all of the progress
+	// made prior to the machine crashing.
+	defer func() {
+		if len(parts) > 0 {
+			if multi == nil {
+				// Parts should be empty if the multi is not initialized
+				panic("Unreachable")
+			} else {
+				if multi.Complete(parts) != nil {
+					multi.Abort()
+				}
+			}
+		}
+	}()
+
+	// Fills from 0 to total from current
+	fromSmallCurrent := func(total int64) error {
+		current, err := d.ReadStream(path, 0)
 		if err != nil {
 			return err
 		}
 
-	if (offset) > int64(len(parts))*chunkSize || (offset < size && offset%chunkSize != 0) {
-		return storagedriver.InvalidOffsetError{Path: path, Offset: offset}
-	}
-
-	if len(parts) > 0 {
-		partNumber = int(offset/chunkSize) + 1
-		totalRead = offset
-		parts = parts[0 : partNumber-1]
-	}
-
-	buf := make([]byte, chunkSize)
-	for {
-		bytesRead, err := io.ReadFull(reader, buf)
-		totalRead += int64(bytesRead)
-
-		if err != nil && err != io.ErrUnexpectedEOF && err != io.EOF {
+		bytesRead = 0
+		for int64(bytesRead) < total {
+			//The loop should very rarely enter a second iteration
+			nn, err := current.Read(buf[bytesRead:total])
+			bytesRead += nn
+			if err != nil {
+				if err != io.EOF {
 					return err
-		} else if (int64(bytesRead) < chunkSize) && totalRead != size {
+				}
+
 				break
-		} else {
-			part, err := multi.PutPart(int(partNumber), bytes.NewReader(buf[0:bytesRead]))
+			}
+
+		}
+		return nil
+	}
+
+	// Fills from parameter to chunkSize from reader
+	fromReader := func(from int64) error {
+		bytesRead = 0
+		for from+int64(bytesRead) < chunkSize {
+			nn, err := reader.Read(buf[from+int64(bytesRead):])
+			totalRead += int64(nn)
+			bytesRead += nn
+
+			if err != nil {
+				if err != io.EOF {
+					return err
+				}
+
+				break
+			}
+		}
+
+		if bytesRead > 0 {
+			part, err = multi.PutPart(int(partNumber), bytes.NewReader(buf[0:int64(bytesRead)+from]))
 			if err != nil {
 				return err
 			}
 
 			parts = append(parts, part)
-			if totalRead == size {
-				multi.Complete(parts)
-				break
+			partNumber++
 		}
 
+		return nil
+	}
+
+	if offset > 0 {
+		resp, err := d.Bucket.Head(d.s3Path(path), nil)
+		if err != nil {
+			if s3Err, ok := err.(*s3.Error); !ok || s3Err.Code != "NoSuchKey" {
+				return 0, err
+			}
+		}
+
+		currentLength := int64(0)
+		if err == nil {
+			currentLength = resp.ContentLength
+		}
+
+		if currentLength >= offset {
+			if offset < chunkSize {
+				// chunkSize > currentLength >= offset
+				if err = fromSmallCurrent(offset); err != nil {
+					return totalRead, err
+				}
+
+				if err = fromReader(offset); err != nil {
+					return totalRead, err
+				}
+
+				if totalRead+offset < chunkSize {
+					return totalRead, nil
+				}
+			} else {
+				// currentLength >= offset >= chunkSize
+				_, part, err = multi.PutPartCopy(partNumber,
+					s3.CopyOptions{CopySourceOptions: "bytes=0-" + strconv.FormatInt(offset-1, 10)},
+					d.Bucket.Name+"/"+d.s3Path(path))
+				if err != nil {
+					return 0, err
+				}
+
+				parts = append(parts, part)
 				partNumber++
 			}
+		} else {
+			// Fills between parameters with 0s but only when to - from <= chunkSize
+			fromZeroFillSmall := func(from, to int64) error {
+				bytesRead = 0
+				for from+int64(bytesRead) < to {
+					nn, err := bytes.NewReader(zeroBuf).Read(buf[from+int64(bytesRead) : to])
+					bytesRead += nn
+					if err != nil {
+						return err
+					}
 				}
 
 				return nil
 			}
 
-// CurrentSize retrieves the curernt size in bytes of the object at the given
-// path.
-func (d *Driver) CurrentSize(path string) (uint64, error) {
-	_, parts, err := d.getAllParts(path)
+			// Fills between parameters with 0s, making new parts
+			fromZeroFillLarge := func(from, to int64) error {
+				bytesRead64 := int64(0)
+				for to-(from+bytesRead64) >= chunkSize {
+					part, err := multi.PutPart(int(partNumber), bytes.NewReader(zeroBuf))
+					if err != nil {
+						return err
+					}
+					bytesRead64 += chunkSize
+
+					parts = append(parts, part)
+					partNumber++
+				}
+
+				return fromZeroFillSmall(0, (to-from)%chunkSize)
+			}
+
+			// currentLength < offset
+			if currentLength < chunkSize {
+				if offset < chunkSize {
+					// chunkSize > offset > currentLength
+					if err = fromSmallCurrent(currentLength); err != nil {
+						return totalRead, err
+					}
+
+					if err = fromZeroFillSmall(currentLength, offset); err != nil {
+						return totalRead, err
+					}
+
+					if err = fromReader(offset); err != nil {
+						return totalRead, err
+					}
+
+					if totalRead+offset < chunkSize {
+						return totalRead, nil
+					}
+				} else {
+					// offset >= chunkSize > currentLength
+					if err = fromSmallCurrent(currentLength); err != nil {
+						return totalRead, err
+					}
+
+					if err = fromZeroFillSmall(currentLength, chunkSize); err != nil {
+						return totalRead, err
+					}
+
+					part, err = multi.PutPart(int(partNumber), bytes.NewReader(buf))
+					if err != nil {
+						return totalRead, err
+					}
+
+					parts = append(parts, part)
+					partNumber++
+
+					//Zero fill from chunkSize up to offset, then some reader
+					if err = fromZeroFillLarge(chunkSize, offset); err != nil {
+						return totalRead, err
+					}
+
+					if err = fromReader(offset % chunkSize); err != nil {
+						return totalRead, err
+					}
+
+					if totalRead+(offset%chunkSize) < chunkSize {
+						return totalRead, nil
+					}
+				}
+			} else {
+				// offset > currentLength >= chunkSize
+				_, part, err = multi.PutPartCopy(partNumber,
+					s3.CopyOptions{CopySourceOptions: "bytes=0-" + strconv.FormatInt(currentLength-1, 10)},
+					d.Bucket.Name+"/"+d.s3Path(path))
 				if err != nil {
 					return 0, err
 				}
 
-	if len(parts) == 0 {
-		return 0, nil
+				parts = append(parts, part)
+				partNumber++
+
+				//Zero fill from currentLength up to offset, then some reader
+				if err = fromZeroFillLarge(currentLength, offset); err != nil {
+					return totalRead, err
 				}
 
-	return (((uint64(len(parts)) - 1) * uint64(parts[0].Size)) + uint64(parts[len(parts)-1].Size)), nil
+				if err = fromReader((offset - currentLength) % chunkSize); err != nil {
+					return totalRead, err
 				}
 
-// List returns a list of the objects that are direct descendants of the given
-// path.
+				if totalRead+((offset-currentLength)%chunkSize) < chunkSize {
+					return totalRead, nil
+				}
+			}
+
+		}
+	}
+
+	for {
+		if err = fromReader(0); err != nil {
+			return totalRead, err
+		}
+
+		if int64(bytesRead) < chunkSize {
+			break
+		}
+	}
+
+	return totalRead, nil
+}
+
+// Stat retrieves the FileInfo for the given path, including the current size
+// in bytes and the creation time.
+func (d *Driver) Stat(path string) (storagedriver.FileInfo, error) {
+	if !storagedriver.PathRegexp.MatchString(path) {
+		return nil, storagedriver.InvalidPathError{Path: path}
+	}
+
+	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(path string) ([]string, error) {
-	if path[len(path)-1] != '/' {
+	if !storagedriver.PathRegexp.MatchString(path) && path != "/" {
+		return nil, storagedriver.InvalidPathError{Path: path}
+	}
+
+	if path != "/" && path[len(path)-1] != '/' {
 		path = path + "/"
 	}
-	listResponse, err := d.Bucket.List(path, "/", "", listPartsMax)
+	listResponse, err := d.Bucket.List(d.s3Path(path), "/", "", listMax)
 	if err != nil {
 		return nil, err
 	}
@@ -219,15 +510,15 @@ func (d *Driver) List(path string) ([]string, error) {
 
 	for {
 		for _, key := range listResponse.Contents {
-			files = append(files, key.Key)
+			files = append(files, strings.Replace(key.Key, d.s3Path(""), "", 1))
 		}
 
 		for _, commonPrefix := range listResponse.CommonPrefixes {
-			directories = append(directories, commonPrefix[0:len(commonPrefix)-1])
+			directories = append(directories, strings.Replace(commonPrefix[0:len(commonPrefix)-1], d.s3Path(""), "", 1))
 		}
 
 		if listResponse.IsTruncated {
-			listResponse, err = d.Bucket.List(path, "/", listResponse.NextMarker, listPartsMax)
+			listResponse, err = d.Bucket.List(d.s3Path(path), "/", listResponse.NextMarker, listMax)
 			if err != nil {
 				return nil, err
 			}
@@ -242,12 +533,17 @@ func (d *Driver) List(path string) ([]string, error) {
 // Move moves an object stored at sourcePath to destPath, removing the original
 // object.
 func (d *Driver) Move(sourcePath string, destPath string) error {
+	if !storagedriver.PathRegexp.MatchString(sourcePath) {
+		return storagedriver.InvalidPathError{Path: sourcePath}
+	} else if !storagedriver.PathRegexp.MatchString(destPath) {
+		return storagedriver.InvalidPathError{Path: destPath}
+	}
+
 	/* This is terrible, but aws doesn't have an actual move. */
-	_, err := d.Bucket.PutCopy(destPath, getPermissions(),
-		s3.CopyOptions{Options: d.getOptions(), MetadataDirective: "", ContentType: d.getContentType()},
-		d.Bucket.Name+"/"+sourcePath)
+	_, 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 storagedriver.PathNotFoundError{Path: sourcePath}
+		return parseError(sourcePath, err)
 	}
 
 	return d.Delete(sourcePath)
@@ -255,12 +551,16 @@ func (d *Driver) Move(sourcePath string, destPath string) error {
 
 // Delete recursively deletes all objects stored at "path" and its subpaths.
 func (d *Driver) Delete(path string) error {
-	listResponse, err := d.Bucket.List(path, "", "", listPartsMax)
+	if !storagedriver.PathRegexp.MatchString(path) {
+		return storagedriver.InvalidPathError{Path: path}
+	}
+
+	listResponse, err := d.Bucket.List(d.s3Path(path), "", "", listMax)
 	if err != nil || len(listResponse.Contents) == 0 {
 		return storagedriver.PathNotFoundError{Path: path}
 	}
 
-	s3Objects := make([]s3.Object, listPartsMax)
+	s3Objects := make([]s3.Object, listMax)
 
 	for len(listResponse.Contents) > 0 {
 		for index, key := range listResponse.Contents {
@@ -272,7 +572,7 @@ func (d *Driver) Delete(path string) error {
 			return nil
 		}
 
-		listResponse, err = d.Bucket.List(path, "", "", listPartsMax)
+		listResponse, err = d.Bucket.List(d.s3Path(path), "", "", listMax)
 		if err != nil {
 			return err
 		}
@@ -281,35 +581,16 @@ func (d *Driver) Delete(path string) error {
 	return nil
 }
 
-func (d *Driver) getHighestIDMulti(path string) (multi *s3.Multi, err error) {
-	multis, _, err := d.Bucket.ListMulti(path, "")
-	if err != nil && !hasCode(err, "NoSuchUpload") {
-		return nil, err
+func (d *Driver) s3Path(path string) string {
+	return strings.TrimLeft(strings.TrimRight(d.rootDirectory, "/")+path, "/")
 }
 
-	uploadID := ""
-
-	if len(multis) > 0 {
-		for _, m := range multis {
-			if m.Key == path && m.UploadId >= uploadID {
-				uploadID = m.UploadId
-				multi = m
-			}
-		}
-		return multi, nil
-	}
-	multi, err = d.Bucket.InitMulti(path, d.getContentType(), getPermissions(), d.getOptions())
-	return multi, err
+func parseError(path string, err error) error {
+	if s3Err, ok := err.(*s3.Error); ok && s3Err.Code == "NoSuchKey" {
+		return storagedriver.PathNotFoundError{Path: path}
 	}
 
-func (d *Driver) getAllParts(path string) (*s3.Multi, []s3.Part, error) {
-	multi, err := d.getHighestIDMulti(path)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	parts, err := multi.ListParts()
-	return multi, parts, err
+	return err
 }
 
 func hasCode(err error, code string) bool {

storagedriver/s3/s3_test.go

@@ -1,8 +1,7 @@
-// +build ignore
-
 package s3
 
 import (
+	"io/ioutil"
 	"os"
 	"strconv"
 	"testing"
@@ -22,13 +21,18 @@ func init() {
 	secretKey := os.Getenv("AWS_SECRET_KEY")
 	bucket := os.Getenv("S3_BUCKET")
 	encrypt := os.Getenv("S3_ENCRYPT")
+	region := os.Getenv("AWS_REGION")
+	root, err := ioutil.TempDir("", "driver-")
+	if err != nil {
+		panic(err)
+	}
 
 	s3DriverConstructor := func(region aws.Region) (storagedriver.StorageDriver, error) {
 		shouldEncrypt, err := strconv.ParseBool(encrypt)
 		if err != nil {
 			return nil, err
 		}
-		return New(accessKey, secretKey, region, shouldEncrypt, bucket)
+		return New(accessKey, secretKey, bucket, root, region, shouldEncrypt)
 	}
 
 	// Skip S3 storage driver tests if environment variable parameters are not provided
@@ -39,18 +43,20 @@ func init() {
 		return ""
 	}
 
-	for _, region := range aws.Regions {
-		if region == aws.USGovWest {
-			continue
-		}
+	// for _, region := range aws.Regions {
+	// 	if region == aws.USGovWest {
+	// 		continue
+	// 	}
 
-		testsuites.RegisterInProcessSuite(s3DriverConstructor(region), skipCheck)
-		testsuites.RegisterIPCSuite(driverName, map[string]string{
-			"accesskey": accessKey,
-			"secretkey": secretKey,
-			"region":    region.Name,
-			"bucket":    bucket,
-			"encrypt":   encrypt,
+	testsuites.RegisterInProcessSuite(func() (storagedriver.StorageDriver, error) {
+		return s3DriverConstructor(aws.GetRegion(region))
 	}, skipCheck)
-	}
+	// testsuites.RegisterIPCSuite(driverName, map[string]string{
+	// 	"accesskey": accessKey,
+	// 	"secretkey": secretKey,
+	// 	"region":    region.Name,
+	// 	"bucket":    bucket,
+	// 	"encrypt":   encrypt,
+	// }, skipCheck)
+	// }
 }

storagedriver/storagedriver.go

@@ -49,8 +49,6 @@ type StorageDriver interface {
 
 	// WriteStream stores the contents of the provided io.ReadCloser at a
 	// location designated by the given path.
-	// The driver will know it has received the full contents when it has read
-	// "size" bytes.
 	// May be used to resume writing a stream by providing a nonzero offset.
 	// The offset must be no larger than the CurrentSize for this path.
 	WriteStream(path string, offset int64, reader io.Reader) (nn int64, err error)

storagedriver/testsuites/testsuites.go

@@ -362,7 +362,7 @@ func (suite *DriverSuite) TestContinueStreamAppend(c *check.C) {
 	filename := randomPath(32)
 	defer suite.StorageDriver.Delete(firstPart(filename))
 
-	chunkSize := int64(10 * 1024 * 1024)
+	chunkSize := int64(5 * 1024 * 1024)
 
 	contentsChunk1 := randomContents(chunkSize)
 	contentsChunk2 := randomContents(chunkSize)
@@ -687,9 +687,11 @@ func (suite *DriverSuite) TestStatCall(c *check.C) {
 	c.Assert(fi.Size(), check.Equals, int64(0))
 	c.Assert(fi.IsDir(), check.Equals, true)
 
-	if start.After(fi.ModTime()) {
-		c.Errorf("modtime %s before file created (%v)", fi.ModTime(), start)
-	}
+	// Directories do not need to support ModTime, since key-value stores
+	// cannot support it efficiently.
+	// if start.After(fi.ModTime()) {
+	// 	c.Errorf("modtime %s before file created (%v)", fi.ModTime(), start)
+	// }
 
 	if fi.ModTime().After(expectedModTime) {
 		c.Errorf("modtime %s after file created (%v)", fi.ModTime(), expectedModTime)
@@ -763,6 +765,54 @@ func (suite *DriverSuite) TestConcurrentFileStreams(c *check.C) {
 	wg.Wait()
 }
 
+// TestEventualConsistency checks that if stat says that a file is a certain size, then
+// you can freely read from the file (this is the only guarantee that the driver needs to provide)
+func (suite *DriverSuite) TestEventualConsistency(c *check.C) {
+	if testing.Short() {
+		c.Skip("Skipping test in short mode")
+	}
+
+	filename := randomPath(32)
+	defer suite.StorageDriver.Delete(firstPart(filename))
+
+	var offset int64
+	var misswrites int
+	var chunkSize int64 = 32
+
+	for i := 0; i < 1024; i++ {
+		contents := randomContents(chunkSize)
+		read, err := suite.StorageDriver.WriteStream(filename, offset, bytes.NewReader(contents))
+		c.Assert(err, check.IsNil)
+
+		fi, err := suite.StorageDriver.Stat(filename)
+		c.Assert(err, check.IsNil)
+
+		// We are most concerned with being able to read data as soon as Stat declares
+		// it is uploaded. This is the strongest guarantee that some drivers (that guarantee
+		// at best eventual consistency) absolutely need to provide.
+		if fi.Size() == offset+chunkSize {
+			reader, err := suite.StorageDriver.ReadStream(filename, offset)
+			c.Assert(err, check.IsNil)
+
+			readContents, err := ioutil.ReadAll(reader)
+			c.Assert(err, check.IsNil)
+
+			c.Assert(readContents, check.DeepEquals, contents)
+
+			reader.Close()
+			offset += read
+		} else {
+			misswrites++
+		}
+	}
+
+	if misswrites > 0 {
+		c.Log("There were " + string(misswrites) + " occurences of a write not being instantly available.")
+	}
+
+	c.Assert(misswrites, check.Not(check.Equals), 1024)
+}
+
 // BenchmarkPutGetEmptyFiles benchmarks PutContent/GetContent for 0B files
 func (suite *DriverSuite) BenchmarkPutGetEmptyFiles(c *check.C) {
 	suite.benchmarkPutGetFiles(c, 0)