diff --git a/storagedriver/base/base.go b/storagedriver/base/base.go new file mode 100644 index 000000000..51fdf512b --- /dev/null +++ b/storagedriver/base/base.go @@ -0,0 +1,141 @@ +// Package base provides a base implementation of the storage driver that can +// be used to implement common checks. The goal is to increase the amount of +// code sharing. +// +// The canonical approach to use this class is to embed in the exported driver +// struct such that calls are proxied through this implementation. First, +// declare the internal driver, as follows: +// +// type driver struct { ... internal ...} +// +// The resulting type should implement StorageDriver such that it can be the +// target of a Base struct. The exported type can then be declared as follows: +// +// type Driver struct { +// Base +// } +// +// Because Driver embeds Base, it effectively implements Base. If the driver +// needs to intercept a call, before going to base, Driver should implement +// that method. Effectively, Driver can intercept calls before coming in and +// driver implements the actual logic. +// +// To further shield the embed from other packages, it is recommended to +// employ a private embed struct: +// +// type baseEmbed struct { +// base.Base +// } +// +// Then, declare driver to embed baseEmbed, rather than Base directly: +// +// type Driver struct { +// baseEmbed +// } +// +// The type now implements StorageDriver, proxying through Base, without +// exporting an unnessecary field. +package base + +import ( + "io" + + "github.com/docker/distribution/storagedriver" +) + +// Base provides a wrapper around a storagedriver implementation that provides +// common path and bounds checking. +type Base struct { + storagedriver.StorageDriver +} + +// GetContent wraps GetContent of underlying storage driver. +func (base *Base) GetContent(path string) ([]byte, error) { + if !storagedriver.PathRegexp.MatchString(path) { + return nil, storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.GetContent(path) +} + +// PutContent wraps PutContent of underlying storage driver. +func (base *Base) PutContent(path string, content []byte) error { + if !storagedriver.PathRegexp.MatchString(path) { + return storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.PutContent(path, content) +} + +// ReadStream wraps ReadStream of underlying storage driver. +func (base *Base) ReadStream(path string, offset int64) (io.ReadCloser, error) { + if offset < 0 { + return nil, storagedriver.InvalidOffsetError{Path: path, Offset: offset} + } + + if !storagedriver.PathRegexp.MatchString(path) { + return nil, storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.ReadStream(path, offset) +} + +// WriteStream wraps WriteStream of underlying storage driver. +func (base *Base) WriteStream(path string, offset int64, reader io.Reader) (nn int64, err error) { + if offset < 0 { + return 0, storagedriver.InvalidOffsetError{Path: path, Offset: offset} + } + + if !storagedriver.PathRegexp.MatchString(path) { + return 0, storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.WriteStream(path, offset, reader) +} + +// Stat wraps Stat of underlying storage driver. +func (base *Base) Stat(path string) (storagedriver.FileInfo, error) { + if !storagedriver.PathRegexp.MatchString(path) { + return nil, storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.Stat(path) +} + +// List wraps List of underlying storage driver. +func (base *Base) List(path string) ([]string, error) { + if !storagedriver.PathRegexp.MatchString(path) && path != "/" { + return nil, storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.List(path) +} + +// Move wraps Move of underlying storage driver. +func (base *Base) 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} + } + + return base.StorageDriver.Move(sourcePath, destPath) +} + +// Delete wraps Delete of underlying storage driver. +func (base *Base) Delete(path string) error { + if !storagedriver.PathRegexp.MatchString(path) { + return storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.Delete(path) +} + +// URLFor wraps URLFor of underlying storage driver. +func (base *Base) URLFor(path string, options map[string]interface{}) (string, error) { + if !storagedriver.PathRegexp.MatchString(path) { + return "", storagedriver.InvalidPathError{Path: path} + } + + return base.StorageDriver.URLFor(path, options) +} diff --git a/storagedriver/filesystem/driver.go b/storagedriver/filesystem/driver.go index 2de7c163a..e76b4bab0 100644 --- a/storagedriver/filesystem/driver.go +++ b/storagedriver/filesystem/driver.go @@ -10,6 +10,7 @@ import ( "time" "github.com/docker/distribution/storagedriver" + "github.com/docker/distribution/storagedriver/base" "github.com/docker/distribution/storagedriver/factory" ) @@ -27,12 +28,20 @@ func (factory *filesystemDriverFactory) Create(parameters map[string]interface{} return FromParameters(parameters), nil } -// Driver is a storagedriver.StorageDriver implementation backed by a local -// filesystem. All provided paths will be subpaths of the RootDirectory -type Driver struct { +type driver struct { rootDirectory string } +type baseEmbed struct { + base.Base +} + +// Driver is a storagedriver.StorageDriver implementation backed by a local +// filesystem. All provided paths will be subpaths of the RootDirectory. +type Driver struct { + baseEmbed +} + // FromParameters constructs a new Driver with a given parameters map // Optional Parameters: // - rootdirectory @@ -49,17 +58,21 @@ func FromParameters(parameters map[string]interface{}) *Driver { // New constructs a new Driver with a given rootDirectory func New(rootDirectory string) *Driver { - return &Driver{rootDirectory} + return &Driver{ + baseEmbed: baseEmbed{ + Base: base.Base{ + StorageDriver: &driver{ + rootDirectory: rootDirectory, + }, + }, + }, + } } // Implement the storagedriver.StorageDriver interface // GetContent retrieves the content stored at "path" as a []byte. -func (d *Driver) GetContent(path string) ([]byte, error) { - if !storagedriver.PathRegexp.MatchString(path) { - return nil, storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) GetContent(path string) ([]byte, error) { rc, err := d.ReadStream(path, 0) if err != nil { return nil, err @@ -75,11 +88,7 @@ func (d *Driver) GetContent(path string) ([]byte, error) { } // PutContent stores the []byte content at a location designated by "path". -func (d *Driver) PutContent(subPath string, contents []byte) error { - if !storagedriver.PathRegexp.MatchString(subPath) { - return storagedriver.InvalidPathError{Path: subPath} - } - +func (d *driver) PutContent(subPath string, contents []byte) error { if _, err := d.WriteStream(subPath, 0, bytes.NewReader(contents)); err != nil { return err } @@ -89,15 +98,7 @@ func (d *Driver) PutContent(subPath string, contents []byte) error { // 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} - } - +func (d *driver) ReadStream(path string, offset int64) (io.ReadCloser, error) { file, err := os.OpenFile(d.fullPath(path), os.O_RDONLY, 0644) if err != nil { if os.IsNotExist(err) { @@ -121,15 +122,7 @@ func (d *Driver) ReadStream(path string, offset int64) (io.ReadCloser, error) { // WriteStream stores the contents of the provided io.Reader at a location // designated by the given path. -func (d *Driver) WriteStream(subPath string, offset int64, reader io.Reader) (nn int64, err error) { - if !storagedriver.PathRegexp.MatchString(subPath) { - return 0, storagedriver.InvalidPathError{Path: subPath} - } - - if offset < 0 { - return 0, storagedriver.InvalidOffsetError{Path: subPath, Offset: offset} - } - +func (d *driver) WriteStream(subPath string, offset int64, reader io.Reader) (nn int64, err error) { // TODO(stevvooe): This needs to be a requirement. // if !path.IsAbs(subPath) { // return fmt.Errorf("absolute path required: %q", subPath) @@ -165,11 +158,7 @@ func (d *Driver) WriteStream(subPath string, offset int64, reader io.Reader) (nn // Stat retrieves the FileInfo for the given path, including the current size // in bytes and the creation time. -func (d *Driver) Stat(subPath string) (storagedriver.FileInfo, error) { - if !storagedriver.PathRegexp.MatchString(subPath) { - return nil, storagedriver.InvalidPathError{Path: subPath} - } - +func (d *driver) Stat(subPath string) (storagedriver.FileInfo, error) { fullPath := d.fullPath(subPath) fi, err := os.Stat(fullPath) @@ -189,11 +178,7 @@ func (d *Driver) Stat(subPath string) (storagedriver.FileInfo, error) { // List returns a list of the objects that are direct descendants of the given // path. -func (d *Driver) List(subPath string) ([]string, error) { - if !storagedriver.PathRegexp.MatchString(subPath) && subPath != "/" { - return nil, storagedriver.InvalidPathError{Path: subPath} - } - +func (d *driver) List(subPath string) ([]string, error) { if subPath[len(subPath)-1] != '/' { subPath += "/" } @@ -224,13 +209,7 @@ func (d *Driver) List(subPath 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} - } - +func (d *driver) Move(sourcePath string, destPath string) error { source := d.fullPath(sourcePath) dest := d.fullPath(destPath) @@ -247,11 +226,7 @@ func (d *Driver) Move(sourcePath string, destPath string) error { } // Delete recursively deletes all objects stored at "path" and its subpaths. -func (d *Driver) Delete(subPath string) error { - if !storagedriver.PathRegexp.MatchString(subPath) { - return storagedriver.InvalidPathError{Path: subPath} - } - +func (d *driver) Delete(subPath string) error { fullPath := d.fullPath(subPath) _, err := os.Stat(fullPath) @@ -267,12 +242,12 @@ func (d *Driver) Delete(subPath string) error { // 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(path string, options map[string]interface{}) (string, error) { +func (d *driver) URLFor(path string, options map[string]interface{}) (string, error) { return "", storagedriver.ErrUnsupportedMethod } // fullPath returns the absolute path of a key within the Driver's storage. -func (d *Driver) fullPath(subPath string) string { +func (d *driver) fullPath(subPath string) string { return path.Join(d.rootDirectory, subPath) } diff --git a/storagedriver/inmemory/driver.go b/storagedriver/inmemory/driver.go index 861e40eb7..d3fdec57d 100644 --- a/storagedriver/inmemory/driver.go +++ b/storagedriver/inmemory/driver.go @@ -9,6 +9,7 @@ import ( "time" "github.com/docker/distribution/storagedriver" + "github.com/docker/distribution/storagedriver/base" "github.com/docker/distribution/storagedriver/factory" ) @@ -25,31 +26,46 @@ func (factory *inMemoryDriverFactory) Create(parameters map[string]interface{}) return New(), nil } -// Driver is a storagedriver.StorageDriver implementation backed by a local map. -// Intended solely for example and testing purposes. -type Driver struct { +type driver struct { root *dir mutex sync.RWMutex } +// baseEmbed allows us to hide the Base embed. +type baseEmbed struct { + base.Base +} + +// Driver is a storagedriver.StorageDriver implementation backed by a local map. +// Intended solely for example and testing purposes. +type Driver struct { + baseEmbed // embedded, hidden base driver. +} + +var _ storagedriver.StorageDriver = &Driver{} + // New constructs a new Driver. func New() *Driver { - return &Driver{root: &dir{ - common: common{ - p: "/", - mod: time.Now(), + return &Driver{ + baseEmbed: baseEmbed{ + Base: base.Base{ + StorageDriver: &driver{ + root: &dir{ + common: common{ + p: "/", + mod: time.Now(), + }, + }, + }, + }, }, - }} + } } // Implement the storagedriver.StorageDriver interface. // GetContent retrieves the content stored at "path" as a []byte. -func (d *Driver) GetContent(path string) ([]byte, error) { - if !storagedriver.PathRegexp.MatchString(path) { - return nil, storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) GetContent(path string) ([]byte, error) { d.mutex.RLock() defer d.mutex.RUnlock() @@ -63,11 +79,7 @@ func (d *Driver) GetContent(path string) ([]byte, error) { } // PutContent stores the []byte content at a location designated by "path". -func (d *Driver) PutContent(p string, contents []byte) error { - if !storagedriver.PathRegexp.MatchString(p) { - return storagedriver.InvalidPathError{Path: p} - } - +func (d *driver) PutContent(p string, contents []byte) error { d.mutex.Lock() defer d.mutex.Unlock() @@ -86,11 +98,7 @@ func (d *Driver) PutContent(p string, contents []byte) error { // 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} - } - +func (d *driver) ReadStream(path string, offset int64) (io.ReadCloser, error) { d.mutex.RLock() defer d.mutex.RUnlock() @@ -114,11 +122,7 @@ func (d *Driver) ReadStream(path string, offset int64) (io.ReadCloser, error) { // WriteStream stores the contents of the provided io.ReadCloser at a location // designated by the given path. -func (d *Driver) WriteStream(path string, offset int64, reader io.Reader) (nn int64, err error) { - if !storagedriver.PathRegexp.MatchString(path) { - return 0, storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) WriteStream(path string, offset int64, reader io.Reader) (nn int64, err error) { d.mutex.Lock() defer d.mutex.Unlock() @@ -159,11 +163,7 @@ func (d *Driver) WriteStream(path string, offset int64, reader io.Reader) (nn in } // Stat returns info about the provided path. -func (d *Driver) Stat(path string) (storagedriver.FileInfo, error) { - if !storagedriver.PathRegexp.MatchString(path) { - return nil, storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) Stat(path string) (storagedriver.FileInfo, error) { d.mutex.RLock() defer d.mutex.RUnlock() @@ -189,11 +189,7 @@ func (d *Driver) Stat(path string) (storagedriver.FileInfo, error) { // List returns a list of the objects that are direct descendants of the given // path. -func (d *Driver) List(path string) ([]string, error) { - if !storagedriver.PathRegexp.MatchString(path) && path != "/" { - return nil, storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) List(path string) ([]string, error) { d.mutex.RLock() defer d.mutex.RUnlock() @@ -223,13 +219,7 @@ 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} - } - +func (d *driver) Move(sourcePath string, destPath string) error { d.mutex.Lock() defer d.mutex.Unlock() @@ -245,11 +235,7 @@ 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 { - if !storagedriver.PathRegexp.MatchString(path) { - return storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) Delete(path string) error { d.mutex.Lock() defer d.mutex.Unlock() @@ -266,6 +252,6 @@ func (d *Driver) Delete(path string) error { // 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(path string, options map[string]interface{}) (string, error) { +func (d *driver) URLFor(path string, options map[string]interface{}) (string, error) { return "", storagedriver.ErrUnsupportedMethod } diff --git a/storagedriver/s3/s3.go b/storagedriver/s3/s3.go index a13166807..0c16e3df5 100644 --- a/storagedriver/s3/s3.go +++ b/storagedriver/s3/s3.go @@ -27,6 +27,7 @@ import ( "github.com/AdRoll/goamz/aws" "github.com/AdRoll/goamz/s3" "github.com/docker/distribution/storagedriver" + "github.com/docker/distribution/storagedriver/base" "github.com/docker/distribution/storagedriver/factory" ) @@ -65,9 +66,7 @@ func (factory *s3DriverFactory) Create(parameters map[string]interface{}) (stora return FromParameters(parameters) } -// Driver is a storagedriver.StorageDriver implementation backed by Amazon S3 -// Objects are stored at absolute keys in the provided bucket -type Driver struct { +type driver struct { S3 *s3.S3 Bucket *s3.Bucket ChunkSize int64 @@ -75,6 +74,16 @@ type Driver struct { RootDirectory string } +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 @@ -209,22 +218,27 @@ func New(params DriverParameters) (*Driver, error) { // } // } - return &Driver{ + d := &driver{ S3: s3obj, Bucket: bucket, ChunkSize: params.ChunkSize, Encrypt: params.Encrypt, - RootDirectory: params.RootDirectory}, nil + RootDirectory: params.RootDirectory, + } + + return &Driver{ + baseEmbed: baseEmbed{ + Base: base.Base{ + StorageDriver: d, + }, + }, + }, nil } // Implement the storagedriver.StorageDriver interface // GetContent retrieves the content stored at "path" as a []byte. -func (d *Driver) GetContent(path string) ([]byte, error) { - if !storagedriver.PathRegexp.MatchString(path) { - return nil, storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) GetContent(path string) ([]byte, error) { content, err := d.Bucket.Get(d.s3Path(path)) if err != nil { return nil, parseError(path, err) @@ -233,25 +247,13 @@ func (d *Driver) GetContent(path string) ([]byte, error) { } // PutContent stores the []byte content at a location designated by "path". -func (d *Driver) PutContent(path string, contents []byte) error { - if !storagedriver.PathRegexp.MatchString(path) { - return storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) PutContent(path string, contents []byte) error { 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} - } - +func (d *driver) ReadStream(path string, offset int64) (io.ReadCloser, error) { headers := make(http.Header) headers.Add("Range", "bytes="+strconv.FormatInt(offset, 10)+"-") @@ -273,15 +275,7 @@ func (d *Driver) ReadStream(path string, offset int64) (io.ReadCloser, error) { // 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} - } - - if offset < 0 { - return 0, storagedriver.InvalidOffsetError{Path: path, Offset: offset} - } - +func (d *driver) WriteStream(path string, offset int64, reader io.Reader) (totalRead int64, err error) { partNumber := 1 bytesRead := 0 var putErrChan chan error @@ -556,11 +550,7 @@ func (d *Driver) WriteStream(path string, offset int64, reader io.Reader) (total // 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} - } - +func (d *driver) Stat(path string) (storagedriver.FileInfo, error) { listResponse, err := d.Bucket.List(d.s3Path(path), "", "", 1) if err != nil { return nil, err @@ -593,11 +583,7 @@ func (d *Driver) Stat(path string) (storagedriver.FileInfo, error) { } // List returns a list of the objects that are direct descendants of the given path. -func (d *Driver) List(path string) ([]string, error) { - if !storagedriver.PathRegexp.MatchString(path) && path != "/" { - return nil, storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) List(path string) ([]string, error) { if path != "/" && path[len(path)-1] != '/' { path = path + "/" } @@ -633,13 +619,7 @@ 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} - } - +func (d *driver) Move(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)) @@ -651,11 +631,7 @@ 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 { - if !storagedriver.PathRegexp.MatchString(path) { - return storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) Delete(path string) error { listResponse, err := d.Bucket.List(d.s3Path(path), "", "", listMax) if err != nil || len(listResponse.Contents) == 0 { return storagedriver.PathNotFoundError{Path: path} @@ -684,11 +660,7 @@ func (d *Driver) Delete(path string) error { // 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(path string, options map[string]interface{}) (string, error) { - if !storagedriver.PathRegexp.MatchString(path) { - return "", storagedriver.InvalidPathError{Path: path} - } - +func (d *driver) URLFor(path string, options map[string]interface{}) (string, error) { methodString := "GET" method, ok := options["method"] if ok { @@ -710,7 +682,7 @@ func (d *Driver) URLFor(path string, options map[string]interface{}) (string, er return d.Bucket.SignedURLWithMethod(methodString, d.s3Path(path), expiresTime, nil, nil), nil } -func (d *Driver) s3Path(path string) string { +func (d *driver) s3Path(path string) string { return strings.TrimLeft(strings.TrimRight(d.RootDirectory, "/")+path, "/") } @@ -727,7 +699,7 @@ func hasCode(err error, code string) bool { return ok && s3err.Code == code } -func (d *Driver) getOptions() s3.Options { +func (d *driver) getOptions() s3.Options { return s3.Options{SSE: d.Encrypt} } @@ -735,6 +707,6 @@ func getPermissions() s3.ACL { return s3.Private } -func (d *Driver) getContentType() string { +func (d *driver) getContentType() string { return "application/octet-stream" }