seaweedfs/weed/shell/command_remote_mount.go
2021-08-26 15:18:34 -07:00

218 lines
6.8 KiB
Go

package shell
import (
"context"
"flag"
"fmt"
"github.com/chrislusf/seaweedfs/weed/filer"
"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
"github.com/chrislusf/seaweedfs/weed/pb/remote_pb"
"github.com/chrislusf/seaweedfs/weed/remote_storage"
"github.com/chrislusf/seaweedfs/weed/util"
"github.com/golang/protobuf/jsonpb"
"github.com/golang/protobuf/proto"
"io"
"strings"
)
func init() {
Commands = append(Commands, &commandRemoteMount{})
}
type commandRemoteMount struct {
}
func (c *commandRemoteMount) Name() string {
return "remote.mount"
}
func (c *commandRemoteMount) Help() string {
return `mount remote storage and pull its metadata
# assume a remote storage is configured to name "cloud1"
remote.configure -name=cloud1 -type=s3 -access_key=xxx -secret_key=yyy
# mount and pull one bucket
remote.mount -dir=/xxx -remote=cloud1/bucket
# mount and pull one directory in the bucket
remote.mount -dir=/xxx -remote=cloud1/bucket/dir1
# after mount, start a separate process to write updates to remote storage
weed filer.remote.sync -filer=<filerHost>:<filerPort> -dir=/xxx
`
}
func (c *commandRemoteMount) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
remoteMountCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
dir := remoteMountCommand.String("dir", "", "a directory in filer")
nonEmpty := remoteMountCommand.Bool("nonempty", false, "allows the mounting over a non-empty directory")
remote := remoteMountCommand.String("remote", "", "a directory in remote storage, ex. <storageName>/<bucket>/path/to/dir")
if err = remoteMountCommand.Parse(args); err != nil {
return nil
}
if *dir == "" {
_, err = listExistingRemoteStorageMounts(commandEnv, writer)
return err
}
remoteStorageLocation := remote_storage.ParseLocation(*remote)
// find configuration for remote storage
// remotePath is /<bucket>/path/to/dir
remoteConf, err := c.findRemoteStorageConfiguration(commandEnv, writer, remoteStorageLocation)
if err != nil {
return fmt.Errorf("find configuration for %s: %v", *remote, err)
}
// sync metadata from remote
if err = c.syncMetadata(commandEnv, writer, *dir, *nonEmpty, remoteConf, remoteStorageLocation); err != nil {
return fmt.Errorf("pull metadata: %v", err)
}
// store a mount configuration in filer
if err = c.saveMountMapping(commandEnv, writer, *dir, remoteStorageLocation); err != nil {
return fmt.Errorf("save mount mapping: %v", err)
}
return nil
}
func listExistingRemoteStorageMounts(commandEnv *CommandEnv, writer io.Writer) (mappings *remote_pb.RemoteStorageMapping, err error) {
// read current mapping
mappings, err = filer.ReadMountMappings(commandEnv.option.GrpcDialOption, commandEnv.option.FilerAddress)
if err != nil {
return mappings, err
}
jsonPrintln(writer, mappings)
return
}
func jsonPrintln(writer io.Writer, message proto.Message) error {
if message == nil {
return nil
}
m := jsonpb.Marshaler{
EmitDefaults: false,
Indent: " ",
}
err := m.Marshal(writer, message)
fmt.Fprintln(writer)
return err
}
func (c *commandRemoteMount) findRemoteStorageConfiguration(commandEnv *CommandEnv, writer io.Writer, remote *remote_pb.RemoteStorageLocation) (conf *remote_pb.RemoteConf, err error) {
return filer.ReadRemoteStorageConf(commandEnv.option.GrpcDialOption, commandEnv.option.FilerAddress, remote.Name)
}
func (c *commandRemoteMount) syncMetadata(commandEnv *CommandEnv, writer io.Writer, dir string, nonEmpty bool, remoteConf *remote_pb.RemoteConf, remote *remote_pb.RemoteStorageLocation) error {
// find existing directory, and ensure the directory is empty
err := commandEnv.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
parent, name := util.FullPath(dir).DirAndName()
_, lookupErr := client.LookupDirectoryEntry(context.Background(), &filer_pb.LookupDirectoryEntryRequest{
Directory: parent,
Name: name,
})
if lookupErr != nil {
if !strings.Contains(lookupErr.Error(), filer_pb.ErrNotFound.Error()) {
return fmt.Errorf("lookup %s: %v", dir, lookupErr)
}
}
mountToDirIsEmpty := true
listErr := filer_pb.SeaweedList(client, dir, "", func(entry *filer_pb.Entry, isLast bool) error {
mountToDirIsEmpty = false
return nil
}, "", false, 1)
if listErr != nil {
return fmt.Errorf("list %s: %v", dir, listErr)
}
if !mountToDirIsEmpty {
if !nonEmpty {
return fmt.Errorf("dir %s is not empty", dir)
}
}
return nil
})
if err != nil {
return err
}
// pull metadata from remote
if err = pullMetadata(commandEnv, writer, util.FullPath(dir), remote, util.FullPath(dir), remoteConf); err != nil {
return fmt.Errorf("cache content data: %v", err)
}
return nil
}
func (c *commandRemoteMount) saveMountMapping(commandEnv *CommandEnv, writer io.Writer, dir string, remoteStorageLocation *remote_pb.RemoteStorageLocation) (err error) {
// read current mapping
var oldContent, newContent []byte
err = commandEnv.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
oldContent, err = filer.ReadInsideFiler(client, filer.DirectoryEtcRemote, filer.REMOTE_STORAGE_MOUNT_FILE)
return err
})
if err != nil {
if err != filer_pb.ErrNotFound {
return fmt.Errorf("read existing mapping: %v", err)
}
}
// add new mapping
newContent, err = filer.AddRemoteStorageMapping(oldContent, dir, remoteStorageLocation)
if err != nil {
return fmt.Errorf("add mapping %s~%s: %v", dir, remoteStorageLocation, err)
}
// save back
err = commandEnv.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
return filer.SaveInsideFiler(client, filer.DirectoryEtcRemote, filer.REMOTE_STORAGE_MOUNT_FILE, newContent)
})
if err != nil {
return fmt.Errorf("save mapping: %v", err)
}
return nil
}
// if an entry has synchronized metadata but has not synchronized content
// entry.Attributes.FileSize == entry.RemoteEntry.RemoteSize
// entry.Attributes.Mtime == entry.RemoteEntry.RemoteMtime
// entry.RemoteEntry.LastLocalSyncTsNs == 0
// if an entry has synchronized metadata but has synchronized content before
// entry.Attributes.FileSize == entry.RemoteEntry.RemoteSize
// entry.Attributes.Mtime == entry.RemoteEntry.RemoteMtime
// entry.RemoteEntry.LastLocalSyncTsNs > 0
// if an entry has synchronized metadata but has new updates
// entry.Attributes.Mtime * 1,000,000,000 > entry.RemoteEntry.LastLocalSyncTsNs
func doSaveRemoteEntry(client filer_pb.SeaweedFilerClient, localDir string, existingEntry *filer_pb.Entry, remoteEntry *filer_pb.RemoteEntry) error {
existingEntry.RemoteEntry = remoteEntry
existingEntry.Attributes.FileSize = uint64(remoteEntry.RemoteSize)
existingEntry.Attributes.Mtime = remoteEntry.RemoteMtime
_, updateErr := client.UpdateEntry(context.Background(), &filer_pb.UpdateEntryRequest{
Directory: localDir,
Entry: existingEntry,
})
if updateErr != nil {
return updateErr
}
return nil
}