rclone/backend/hdfs/fs.go
Tayo-pasedaRJ 0548e61910
hdfs: added support for list of namenodes in hdfs remote config
Users can now input a comma separated list of namenodes when writing
config for hdfs remotes.

This is required when you have multiple namenodes in your hdfs cluster
and cannot be certain which namenodes will be in 'standby' or 'active'
states.

This was available before but wasn't documented and didn't use the
correct rclone interfaces.
2023-11-13 15:55:52 +00:00

424 lines
9.8 KiB
Go

//go:build !plan9
// +build !plan9
package hdfs
import (
"context"
"fmt"
"io"
"os"
"os/user"
"path"
"strings"
"time"
"github.com/colinmarc/hdfs/v2"
krb "github.com/jcmturner/gokrb5/v8/client"
"github.com/jcmturner/gokrb5/v8/config"
"github.com/jcmturner/gokrb5/v8/credentials"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/config/configmap"
"github.com/rclone/rclone/fs/config/configstruct"
"github.com/rclone/rclone/fs/hash"
"github.com/rclone/rclone/lib/pacer"
)
// Fs represents a HDFS server
type Fs struct {
name string
root string
features *fs.Features // optional features
opt Options // options for this backend
ci *fs.ConfigInfo // global config
client *hdfs.Client
pacer *fs.Pacer // pacer for API calls
}
const (
minSleep = 20 * time.Millisecond
maxSleep = 10 * time.Second
decayConstant = 2 // bigger for slower decay, exponential
)
// copy-paste from https://github.com/colinmarc/hdfs/blob/master/cmd/hdfs/kerberos.go
func getKerberosClient() (*krb.Client, error) {
configPath := os.Getenv("KRB5_CONFIG")
if configPath == "" {
configPath = "/etc/krb5.conf"
}
cfg, err := config.Load(configPath)
if err != nil {
return nil, err
}
// Determine the ccache location from the environment, falling back to the
// default location.
ccachePath := os.Getenv("KRB5CCNAME")
if strings.Contains(ccachePath, ":") {
if strings.HasPrefix(ccachePath, "FILE:") {
ccachePath = strings.SplitN(ccachePath, ":", 2)[1]
} else {
return nil, fmt.Errorf("unusable ccache: %s", ccachePath)
}
} else if ccachePath == "" {
u, err := user.Current()
if err != nil {
return nil, err
}
ccachePath = fmt.Sprintf("/tmp/krb5cc_%s", u.Uid)
}
ccache, err := credentials.LoadCCache(ccachePath)
if err != nil {
return nil, err
}
client, err := krb.NewFromCCache(ccache, cfg)
if err != nil {
return nil, err
}
return client, nil
}
// NewFs constructs an Fs from the path
func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, error) {
opt := new(Options)
err := configstruct.Set(m, opt)
if err != nil {
return nil, err
}
options := hdfs.ClientOptions{
Addresses: opt.Namenode,
UseDatanodeHostname: false,
}
if opt.ServicePrincipalName != "" {
options.KerberosClient, err = getKerberosClient()
if err != nil {
return nil, fmt.Errorf("problem with kerberos authentication: %w", err)
}
options.KerberosServicePrincipleName = opt.ServicePrincipalName
if opt.DataTransferProtection != "" {
options.DataTransferProtection = opt.DataTransferProtection
}
} else {
options.User = opt.Username
}
client, err := hdfs.NewClient(options)
if err != nil {
return nil, err
}
f := &Fs{
name: name,
root: root,
opt: *opt,
ci: fs.GetConfig(ctx),
client: client,
pacer: fs.NewPacer(ctx, pacer.NewDefault(pacer.MinSleep(minSleep), pacer.MaxSleep(maxSleep), pacer.DecayConstant(decayConstant))),
}
f.features = (&fs.Features{
CanHaveEmptyDirectories: true,
}).Fill(ctx, f)
info, err := f.client.Stat(f.realpath(""))
if err == nil && !info.IsDir() {
f.root = path.Dir(f.root)
return f, fs.ErrorIsFile
}
return f, nil
}
// Name of this fs
func (f *Fs) Name() string {
return f.name
}
// Root of the remote (as passed into NewFs)
func (f *Fs) Root() string {
return f.root
}
// String returns a description of the FS
func (f *Fs) String() string {
return fmt.Sprintf("hdfs://%s", f.opt.Namenode)
}
// Features returns the optional features of this Fs
func (f *Fs) Features() *fs.Features {
return f.features
}
// Precision return the precision of this Fs
func (f *Fs) Precision() time.Duration {
return time.Second
}
// Hashes are not supported
func (f *Fs) Hashes() hash.Set {
return hash.Set(hash.None)
}
// NewObject finds file at remote or return fs.ErrorObjectNotFound
func (f *Fs) NewObject(ctx context.Context, remote string) (fs.Object, error) {
realpath := f.realpath(remote)
fs.Debugf(f, "new [%s]", realpath)
info, err := f.ensureFile(realpath)
if err != nil {
return nil, err
}
return &Object{
fs: f,
remote: remote,
size: info.Size(),
modTime: info.ModTime(),
}, nil
}
// List the objects and directories in dir into entries.
func (f *Fs) List(ctx context.Context, dir string) (entries fs.DirEntries, err error) {
realpath := f.realpath(dir)
fs.Debugf(f, "list [%s]", realpath)
err = f.ensureDirectory(realpath)
if err != nil {
return nil, err
}
list, err := f.client.ReadDir(realpath)
if err != nil {
return nil, err
}
for _, x := range list {
stdName := f.opt.Enc.ToStandardName(x.Name())
remote := path.Join(dir, stdName)
if x.IsDir() {
entries = append(entries, fs.NewDir(remote, x.ModTime()))
} else {
entries = append(entries, &Object{
fs: f,
remote: remote,
size: x.Size(),
modTime: x.ModTime()})
}
}
return entries, nil
}
// Put the object
func (f *Fs) Put(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (fs.Object, error) {
o := &Object{
fs: f,
remote: src.Remote(),
}
err := o.Update(ctx, in, src, options...)
return o, err
}
// PutStream uploads to the remote path with the modTime given of indeterminate size
func (f *Fs) PutStream(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (fs.Object, error) {
return f.Put(ctx, in, src, options...)
}
// Mkdir makes a directory
func (f *Fs) Mkdir(ctx context.Context, dir string) error {
fs.Debugf(f, "mkdir [%s]", f.realpath(dir))
return f.client.MkdirAll(f.realpath(dir), 0755)
}
// Rmdir deletes the directory
func (f *Fs) Rmdir(ctx context.Context, dir string) error {
realpath := f.realpath(dir)
fs.Debugf(f, "rmdir [%s]", realpath)
err := f.ensureDirectory(realpath)
if err != nil {
return err
}
// do not remove empty directory
list, err := f.client.ReadDir(realpath)
if err != nil {
return err
}
if len(list) > 0 {
return fs.ErrorDirectoryNotEmpty
}
return f.client.Remove(realpath)
}
// Purge deletes all the files in the directory
func (f *Fs) Purge(ctx context.Context, dir string) error {
realpath := f.realpath(dir)
fs.Debugf(f, "purge [%s]", realpath)
err := f.ensureDirectory(realpath)
if err != nil {
return err
}
return f.client.RemoveAll(realpath)
}
// Move src to this remote using server-side move operations.
//
// This is stored with the remote path given.
//
// It returns the destination Object and a possible error.
//
// Will only be called if src.Fs().Name() == f.Name()
//
// If it isn't possible then return fs.ErrorCantMove
func (f *Fs) Move(ctx context.Context, src fs.Object, remote string) (fs.Object, error) {
srcObj, ok := src.(*Object)
if !ok {
fs.Debugf(src, "Can't move - not same remote type")
return nil, fs.ErrorCantMove
}
// Get the real paths from the remote specs:
sourcePath := srcObj.fs.realpath(srcObj.remote)
targetPath := f.realpath(remote)
fs.Debugf(f, "rename [%s] to [%s]", sourcePath, targetPath)
// Make sure the target folder exists:
dirname := path.Dir(targetPath)
err := f.client.MkdirAll(dirname, 0755)
if err != nil {
return nil, err
}
// Do the move
// Note that the underlying HDFS library hard-codes Overwrite=True, but this is expected rclone behaviour.
err = f.client.Rename(sourcePath, targetPath)
if err != nil {
return nil, err
}
// Look up the resulting object
info, err := f.client.Stat(targetPath)
if err != nil {
return nil, err
}
// And return it:
return &Object{
fs: f,
remote: remote,
size: info.Size(),
modTime: info.ModTime(),
}, nil
}
// DirMove moves src, srcRemote to this remote at dstRemote
// using server-side move operations.
//
// Will only be called if src.Fs().Name() == f.Name()
//
// If it isn't possible then return fs.ErrorCantDirMove
//
// If destination exists then return fs.ErrorDirExists
func (f *Fs) DirMove(ctx context.Context, src fs.Fs, srcRemote, dstRemote string) (err error) {
srcFs, ok := src.(*Fs)
if !ok {
return fs.ErrorCantDirMove
}
// Get the real paths from the remote specs:
sourcePath := srcFs.realpath(srcRemote)
targetPath := f.realpath(dstRemote)
fs.Debugf(f, "rename [%s] to [%s]", sourcePath, targetPath)
// Check if the destination exists:
info, err := f.client.Stat(targetPath)
if err == nil {
fs.Debugf(f, "target directory already exits, IsDir = [%t]", info.IsDir())
return fs.ErrorDirExists
}
// Make sure the targets parent folder exists:
dirname := path.Dir(targetPath)
err = f.client.MkdirAll(dirname, 0755)
if err != nil {
return err
}
// Do the move
err = f.client.Rename(sourcePath, targetPath)
if err != nil {
return err
}
return nil
}
// About gets quota information from the Fs
func (f *Fs) About(ctx context.Context) (*fs.Usage, error) {
info, err := f.client.StatFs()
if err != nil {
return nil, err
}
return &fs.Usage{
Total: fs.NewUsageValue(int64(info.Capacity)),
Used: fs.NewUsageValue(int64(info.Used)),
Free: fs.NewUsageValue(int64(info.Remaining)),
}, nil
}
func (f *Fs) ensureDirectory(realpath string) error {
info, err := f.client.Stat(realpath)
if e, ok := err.(*os.PathError); ok && e.Err == os.ErrNotExist {
return fs.ErrorDirNotFound
}
if err != nil {
return err
}
if !info.IsDir() {
return fs.ErrorDirNotFound
}
return nil
}
func (f *Fs) ensureFile(realpath string) (os.FileInfo, error) {
info, err := f.client.Stat(realpath)
if e, ok := err.(*os.PathError); ok && e.Err == os.ErrNotExist {
return nil, fs.ErrorObjectNotFound
}
if err != nil {
return nil, err
}
if info.IsDir() {
return nil, fs.ErrorObjectNotFound
}
return info, nil
}
func (f *Fs) realpath(dir string) string {
return f.opt.Enc.FromStandardPath(xPath(f.Root(), dir))
}
// Check the interfaces are satisfied
var (
_ fs.Fs = (*Fs)(nil)
_ fs.Purger = (*Fs)(nil)
_ fs.PutStreamer = (*Fs)(nil)
_ fs.Abouter = (*Fs)(nil)
_ fs.Mover = (*Fs)(nil)
_ fs.DirMover = (*Fs)(nil)
)