Add SftpFs beta backend

README.md

@@ -263,12 +263,17 @@ backed file implementation. This can be used in other memory backed file
 systems with ease. Plans are to add a radix tree memory stored file
 system using InMemoryFile.
 
+## SftpFs
+
+Afero has experimental support for secure file transfer protocol (sftp). Which can
+be used to perform file operations over a encrypted channel.
+
 ## Desired/possible backends
 
 The following is a short list of possible backends we hope someone will
 implement:
 
-* SSH/SCP
+* SSH
 * ZIP
 * TAR
 * S3

sftp.go

@@ -0,0 +1,128 @@
+// Copyright © 2015 Jerry Jacobs <jerry.jacobs@xor-gate.org>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"os"
+	"time"
+
+	"github.com/spf13/afero/sftp"
+
+	"github.com/pkg/sftp"
+)
+
+// SftpFs is a Fs implementation that uses functions provided by the sftp package.
+//
+// For details in any method, check the documentation of the sftp package
+// (github.com/pkg/sftp).
+type SftpFs struct{
+	SftpClient  *sftp.Client
+}
+
+func (s SftpFs) Name() string { return "SftpFs" }
+
+func (s SftpFs) Create(name string) (File, error) {
+	f, err := sftpfs.FileCreate(s.SftpClient, name)
+	return f, err
+}
+
+func (s SftpFs) Mkdir(name string, perm os.FileMode) error {
+	err := s.SftpClient.Mkdir(name)
+	if err != nil {
+		return err
+	}
+	return s.SftpClient.Chmod(name, perm)
+}
+
+func (s SftpFs) MkdirAll(path string, perm os.FileMode) error {
+	// Fast path: if we can tell whether path is a directory or file, stop with success or error.
+	dir, err := s.Stat(path)
+	if err == nil {
+		if dir.IsDir() {
+			return nil
+		}
+		return err
+	}
+
+	// Slow path: make sure parent exists and then call Mkdir for path.
+	i := len(path)
+	for i > 0 && os.IsPathSeparator(path[i-1]) { // Skip trailing path separator.
+		i--
+	}
+
+	j := i
+	for j > 0 && !os.IsPathSeparator(path[j-1]) { // Scan backward over element.
+		j--
+	}
+
+	if j > 1 {
+		// Create parent
+		err = s.MkdirAll(path[0:j-1], perm)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Parent now exists; invoke Mkdir and use its result.
+	err = s.Mkdir(path, perm)
+	if err != nil {
+		// Handle arguments like "foo/." by
+		// double-checking that directory doesn't exist.
+		dir, err1 := s.Lstat(path)
+		if err1 == nil && dir.IsDir() {
+			return nil
+		}
+		return err
+	}
+	return nil
+}
+
+func (s SftpFs) Open(name string) (File, error) {
+	f, err := sftpfs.FileOpen(s.SftpClient, name)
+	return f, err
+}
+
+func (s SftpFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	return nil,nil
+}
+
+func (s SftpFs) Remove(name string) error {
+	return s.SftpClient.Remove(name)
+}
+
+func (s SftpFs) RemoveAll(path string) error {
+	// TODO have a look at os.RemoveAll
+	// https://github.com/golang/go/blob/master/src/os/path.go#L66
+	return nil
+}
+
+func (s SftpFs) Rename(oldname, newname string) error {
+	return s.SftpClient.Rename(oldname, newname)
+}
+
+func (s SftpFs) Stat(name string) (os.FileInfo, error) {
+	return s.SftpClient.Stat(name)
+}
+
+func (s SftpFs) Lstat(p string) (os.FileInfo, error) {
+	return s.SftpClient.Lstat(p)
+}
+
+func (s SftpFs) Chmod(name string, mode os.FileMode) error {
+	return s.SftpClient.Chmod(name, mode)
+}
+
+func (s SftpFs) Chtimes(name string, atime time.Time, mtime time.Time) error {
+	return s.SftpClient.Chtimes(name, atime, mtime)
+}

sftp/file.go

@@ -0,0 +1,95 @@
+// Copyright © 2015 Jerry Jacobs <jerry.jacobs@xor-gate.org>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sftpfs
+
+import (
+	"os"
+	"github.com/pkg/sftp"
+)
+
+type File struct {
+	fd *sftp.File
+}
+
+func FileOpen(s *sftp.Client, name string) (*File, error) {
+	fd, err := s.Open(name)
+	if err != nil {
+		return &File{}, err
+	}
+	return &File{fd: fd}, nil
+}
+
+func FileCreate(s *sftp.Client, name string) (*File, error) {
+	fd, err := s.Create(name)
+	if err != nil {
+		return &File{}, err
+	}
+	return &File{fd: fd}, nil
+}
+
+func (f *File) Close() error {
+	return f.fd.Close()
+}
+
+func (f *File) Name() string {
+	return f.fd.Name()
+}
+
+func (f *File) Stat() (os.FileInfo, error) {
+	return f.fd.Stat()
+}
+
+func (f *File) Sync() error {
+	return nil
+}
+
+func (f *File) Truncate(size int64) error {
+	return f.fd.Truncate(size)
+}
+
+func (f *File) Read(b []byte) (n int, err error) {
+	return f.fd.Read(b)
+}
+
+// TODO
+func (f *File) ReadAt(b []byte, off int64) (n int, err error) {
+	return 0,nil
+}
+
+// TODO
+func (f *File) Readdir(count int) (res []os.FileInfo, err error) {
+	return nil,nil
+}
+
+// TODO
+func (f *File) Readdirnames(n int) (names []string, err error) {
+	return nil,nil
+}
+
+func (f *File) Seek(offset int64, whence int) (int64, error) {
+	return f.fd.Seek(offset, whence)
+}
+
+func (f *File) Write(b []byte) (n int, err error) {
+	return f.fd.Write(b)
+}
+
+// TODO
+func (f *File) WriteAt(b []byte, off int64) (n int, err error) {
+	return 0,nil
+}
+
+func (f *File) WriteString(s string) (ret int, err error) {
+	return f.fd.Write([]byte(s))
+}

sftp_test.go

@@ -0,0 +1,92 @@
+// Copyright © 2015 Jerry Jacobs <jerry.jacobs@xor-gate.org>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"os"
+	"io/ioutil"
+	"testing"
+
+	"github.com/xor-gate/afero"
+
+	"golang.org/x/crypto/ssh"
+	"github.com/pkg/sftp"
+)
+
+type SftpFsContext struct {
+	sshc   *ssh.Client
+	sshcfg *ssh.ClientConfig
+	sftpc  *sftp.Client
+}
+
+func SftpConnect(user string, host string) (*SftpFsContext, error) {
+	pemBytes, err := ioutil.ReadFile(os.Getenv("HOME") + "/.ssh/id_rsa")
+	if err != nil {
+		return nil,err
+	}
+
+	signer, err := ssh.ParsePrivateKey(pemBytes)
+	if err != nil {
+		return nil,err
+	}
+
+	sshcfg := &ssh.ClientConfig{
+		User: user,
+		Auth: []ssh.AuthMethod{
+			ssh.PublicKeys(signer),
+		},
+	}
+
+	sshc, err := ssh.Dial("tcp", host, sshcfg)
+	if err != nil {
+		return nil,err
+	}
+
+	sftpc, err := sftp.NewClient(sshc)
+	if err != nil {
+		return nil,err
+	}
+
+	ctx := &SftpFsContext{
+		sshc: sshc,
+		sshcfg: sshcfg,
+		sftpc: sftpc,
+	}
+
+	return ctx,nil
+}
+
+func (ctx *SftpFsContext) Disconnect() error {
+	ctx.sftpc.Close()
+	ctx.sshc.Close()
+	return nil
+}
+
+func TestSftpCreate(t *testing.T) {
+	ctx, err := SftpConnect("user", "host:port")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer ctx.Disconnect()
+
+	var AppFs afero.Fs = afero.SftpFs{
+		SftpClient: ctx.sftpc,
+	}
+
+	file, err := AppFs.Create("aferoSftpFsTestFile")
+	if err != nil {
+		t.Error(err)
+	}
+	defer file.Close()
+}