package fs import ( "bytes" "errors" "io/ioutil" "os" "path" "strings" "time" "go4.org/wkfs" "github.com/aws/aws-sdk-go/aws" "github.com/aws/aws-sdk-go/aws/awserr" "github.com/aws/aws-sdk-go/aws/credentials" "github.com/aws/aws-sdk-go/aws/session" "github.com/aws/aws-sdk-go/service/s3" "github.com/nsheridan/cashier/server/config" ) // Register the /s3/ filesystem as a well-known filesystem. func Register(config *config.AWS) { ac := &aws.Config{} // If region is unset the SDK will attempt to read the region from the environment. if config.Region != "" { ac.Region = aws.String(config.Region) } // Attempt to get credentials from the cashier config. // Otherwise check for standard credentials. If neither are present register the fs as broken. // TODO: implement this as a provider. if config.AccessKey != "" && config.SecretKey != "" { ac.Credentials = credentials.NewStaticCredentials(config.AccessKey, config.SecretKey, "") } else { _, err := session.New().Config.Credentials.Get() if err != nil { registerBrokenFS(errors.New("aws credentials not found")) return } } sc := s3.New(session.New(ac)) if aws.StringValue(sc.Config.Region) == "" { registerBrokenFS(errors.New("aws region configuration not found")) return } wkfs.RegisterFS("/s3/", &s3FS{ sc: sc, }) } func registerBrokenFS(err error) { wkfs.RegisterFS("/s3/", &s3FS{ err: err, }) } type s3FS struct { sc *s3.S3 err error } func (fs *s3FS) parseName(name string) (bucket, fileName string, err error) { if fs.err != nil { return "", "", fs.err } name = strings.TrimPrefix(name, "/s3/") i := strings.Index(name, "/") if i < 0 { return name, "", nil } return name[:i], name[i+1:], nil } // Open opens the named file for reading. func (fs *s3FS) Open(name string) (wkfs.File, error) { bucket, fileName, err := fs.parseName(name) if err != nil { return nil, err } obj, err := fs.sc.GetObject(&s3.GetObjectInput{ Bucket: &bucket, Key: &fileName, }) if err != nil { return nil, err } defer obj.Body.Close() slurp, err := ioutil.ReadAll(obj.Body) if err != nil { return nil, err } return &file{ name: name, Reader: bytes.NewReader(slurp), }, nil } func (fs *s3FS) Stat(name string) (os.FileInfo, error) { return fs.Lstat(name) } func (fs *s3FS) Lstat(name string) (os.FileInfo, error) { bucket, fileName, err := fs.parseName(name) if err != nil { return nil, err } obj, err := fs.sc.GetObject(&s3.GetObjectInput{ Bucket: &bucket, Key: &fileName, }) if err != nil { if awsErr, ok := err.(awserr.Error); ok { if awsErr.Code() == "NoSuchKey" { return nil, os.ErrNotExist } } } if err != nil { return nil, err } return &statInfo{ name: path.Base(fileName), size: *obj.ContentLength, }, nil } func (fs *s3FS) MkdirAll(path string, perm os.FileMode) error { return nil } func (fs *s3FS) OpenFile(name string, flag int, perm os.FileMode) (wkfs.FileWriter, error) { return nil, errors.New("not implemented") } type statInfo struct { name string size int64 isDir bool modtime time.Time } func (si *statInfo) IsDir() bool { return si.isDir } func (si *statInfo) ModTime() time.Time { return si.modtime } func (si *statInfo) Mode() os.FileMode { return 0644 } func (si *statInfo) Name() string { return path.Base(si.name) } func (si *statInfo) Size() int64 { return si.size } func (si *statInfo) Sys() interface{} { return nil } type file struct { name string *bytes.Reader } func (*file) Close() error { return nil } func (f *file) Name() string { return path.Base(f.name) } func (f *file) Stat() (os.FileInfo, error) { panic("Stat not implemented on /s3/ files yet") }