shell: add "remote.meta.sync"

1 files changed, 208 insertions, 0 deletions

diff --git a/weed/shell/command_remote_meta_sync.go b/weed/shell/command_remote_meta_sync.go
new file mode 100644
index 000000000..7e111143c
--- /dev/null
+++ b/weed/shell/command_remote_meta_sync.go
@@ -0,0 +1,208 @@
+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/remote_storage"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"io"
+	"strings"
+)
+
+func init() {
+	Commands = append(Commands, &commandRemoteMetaSync{})
+}
+
+type commandRemoteMetaSync struct {
+}
+
+func (c *commandRemoteMetaSync) Name() string {
+	return "remote.meta.sync"
+}
+
+func (c *commandRemoteMetaSync) Help() string {
+	return `synchronize the local file meta data with the remote file 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
+
+	After mount, if the remote file can be changed, 
+	run this command to synchronize the metadata of the mounted folder or any sub folder
+
+		remote.meta.sync -dir=/xxx
+		remote.meta.sync -dir=/xxx/some/subdir
+
+	This is designed to run regularly. So you can add it to some cronjob.
+
+	If there are no other operations changing remote files, this operation is not needed.
+
+`
+}
+
+func (c *commandRemoteMetaSync) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	remoteMetaSyncCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
+
+	dir := remoteMetaSyncCommand.String("dir", "", "a directory in filer")
+
+	if err = remoteMetaSyncCommand.Parse(args); err != nil {
+		return nil
+	}
+
+	localMountedDir, remoteStorageMountedLocation, remoteStorageConf, detectErr := detectMountInfo(commandEnv, writer, *dir)
+	if detectErr != nil{
+		return detectErr
+	}
+
+	// pull metadata from remote
+	if err = pullMetadata(commandEnv, writer, util.FullPath(localMountedDir), remoteStorageMountedLocation, util.FullPath(*dir), remoteStorageConf); err != nil {
+		return fmt.Errorf("cache content data: %v", err)
+	}
+
+	return nil
+}
+
+func detectMountInfo(commandEnv *CommandEnv, writer io.Writer, dir string) (string, *filer_pb.RemoteStorageLocation, *filer_pb.RemoteConf, error) {
+	mappings, listErr := filer.ReadMountMappings(commandEnv.option.GrpcDialOption, commandEnv.option.FilerAddress)
+	if listErr != nil {
+		return "", nil, nil, listErr
+	}
+	if dir == "" {
+		jsonPrintln(writer, mappings)
+		return "", nil, nil, fmt.Errorf("need to specify '-dir' option")
+	}
+
+	var localMountedDir string
+	var remoteStorageMountedLocation *filer_pb.RemoteStorageLocation
+	for k, loc := range mappings.Mappings {
+		if strings.HasPrefix(dir, k) {
+			localMountedDir, remoteStorageMountedLocation = k, loc
+		}
+	}
+	if localMountedDir == "" {
+		jsonPrintln(writer, mappings)
+		return "", nil, nil, fmt.Errorf("%s is not mounted", dir)
+	}
+
+	// find remote storage configuration
+	remoteStorageConf, err := filer.ReadRemoteStorageConf(commandEnv.option.GrpcDialOption, commandEnv.option.FilerAddress, remoteStorageMountedLocation.Name)
+	if err != nil {
+		return "", nil, nil, err
+	}
+
+	return localMountedDir, remoteStorageMountedLocation, remoteStorageConf, nil
+}
+
+/*
+  This function update entry.RemoteEntry if the remote has any changes.
+
+  To pull remote updates, or created for the first time, the criteria is:
+    entry == nil or (entry.RemoteEntry != nil and entry.RemoteEntry.RemoteTag != remote.RemoteTag)
+  After the meta pull, the entry.RemoteEntry will have:
+    remoteEntry.LastLocalSyncTsNs == 0
+    Attributes.FileSize = uint64(remoteEntry.RemoteSize)
+    Attributes.Mtime = remoteEntry.RemoteMtime
+    remoteEntry.RemoteTag   = actual remote tag
+    chunks = nil
+
+  When reading the file content or pulling the file content in "remote.cache", the criteria is:
+    Attributes.FileSize > 0 and len(chunks) == 0
+  After caching the file content, the entry.RemoteEntry will be
+    remoteEntry.LastLocalSyncTsNs == time.Now.UnixNano()
+    Attributes.FileSize = uint64(remoteEntry.RemoteSize)
+    Attributes.Mtime = remoteEntry.RemoteMtime
+    chunks = non-emtpy
+
+  When "weed filer.remote.sync" to upload local changes to remote, the criteria is:
+    Attributes.Mtime > remoteEntry.RemoteMtime
+  Right after "weed filer.remote.sync", the entry.RemoteEntry will be
+    remoteEntry.LastLocalSyncTsNs = time.Now.UnixNano()
+    remoteEntry.RemoteSize  = actual remote size, which should equal to entry.Attributes.FileSize
+    remoteEntry.RemoteMtime = actual remote mtime, which should be a little greater than entry.Attributes.Mtime
+    remoteEntry.RemoteTag   = actual remote tag
+
+
+  If entry does not exists, need to pull meta
+  If entry.RemoteEntry == nil, this is a new local change and should not be overwritten
+  If entry.RemoteEntry.RemoteTag != remoteEntry.RemoteTag {
+    the remote version is updated, need to pull meta
+  }
+ */
+func pullMetadata(commandEnv *CommandEnv, writer io.Writer, localMountedDir util.FullPath, remoteMountedLocation *filer_pb.RemoteStorageLocation, dirToCache util.FullPath, remoteConf *filer_pb.RemoteConf) error {
+
+	// visit remote storage
+	remoteStorage, err := remote_storage.GetRemoteStorage(remoteConf)
+	if err != nil {
+		return err
+	}
+
+	remote := filer.MapFullPathToRemoteStorageLocation(localMountedDir, remoteMountedLocation, dirToCache)
+	println("local :", localMountedDir)
+	println("remote:", remoteMountedLocation.Path)
+	println("local+:", dirToCache)
+	println("remote+:", remote.Path)
+
+	err = commandEnv.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
+		ctx := context.Background()
+		err = remoteStorage.Traverse(remote, func(remoteDir, name string, isDirectory bool, remoteEntry *filer_pb.RemoteEntry) error {
+			localDir := filer.MapRemoteStorageLocationPathToFullPath(localMountedDir, remoteMountedLocation, remoteDir)
+			fmt.Fprint(writer, localDir.Child(name))
+
+			lookupResponse, lookupErr := filer_pb.LookupEntry(client, &filer_pb.LookupDirectoryEntryRequest{
+				Directory: string(localDir),
+				Name:      name,
+			})
+			var existingEntry *filer_pb.Entry
+			if lookupErr != nil {
+				if lookupErr != filer_pb.ErrNotFound {
+					return lookupErr
+				}
+			} else {
+				existingEntry = lookupResponse.Entry
+			}
+
+			if existingEntry == nil {
+				_, createErr := client.CreateEntry(ctx, &filer_pb.CreateEntryRequest{
+					Directory: string(localDir),
+					Entry: &filer_pb.Entry{
+						Name:        name,
+						IsDirectory: isDirectory,
+						Attributes: &filer_pb.FuseAttributes{
+							FileSize: uint64(remoteEntry.RemoteSize),
+							Mtime:    remoteEntry.RemoteMtime,
+							FileMode: uint32(0644),
+						},
+						RemoteEntry: remoteEntry,
+					},
+				})
+				fmt.Fprintln(writer, " (create)")
+				return createErr
+			} else {
+				if existingEntry.RemoteEntry == nil {
+					// this is a new local change and should not be overwritten
+					fmt.Fprintln(writer, " (skip)")
+					return nil
+				}
+				if existingEntry.RemoteEntry.RemoteETag != remoteEntry.RemoteETag {
+					// the remote version is updated, need to pull meta
+					fmt.Fprintln(writer, " (update)")
+					return doSaveRemoteEntry(client, string(localDir), existingEntry, remoteEntry)
+				}
+			}
+			fmt.Fprintln(writer, " (skip)")
+			return nil
+		})
+		return err
+	})
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}