Files
goblin-store/lib/backup/rclone.go
T

134 lines
3.6 KiB
Go

package backup
import (
"context"
"errors"
"fmt"
"path/filepath"
"sort"
"time"
"git.metaunix.net/bitgoblin/goblin-store/lib/config"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/operations"
"github.com/rclone/rclone/fs/sync"
// Register desired backends
_ "github.com/rclone/rclone/backend/local"
_ "github.com/rclone/rclone/backend/s3"
)
func RunIncrementalBackup(ctx context.Context, cfg *config.Config) error {
// Configure global Rclone concurrency parameters
ci := fs.GetConfig(ctx)
ci.Transfers = cfg.Workers
ci.Checkers = cfg.Workers * 2
// Setup directories:
// - destination/latest: holds current full mirror
// - destination/increments/<timestamp>: holds files altered or deleted during sync
timestamp := time.Now().Format("2006-01-02_15-04-05")
latestDir := filepath.Join(cfg.Destination, "latest")
incrementDir := filepath.Join(cfg.Destination, "increments", timestamp)
incrementsBase := filepath.Join(cfg.Destination, "increments")
// 1. Resolve source and target filesystems
fSrc, err := fs.NewFs(ctx, cfg.Source)
if err != nil {
return fmt.Errorf("failed to open source %q: %w", cfg.Source, err)
}
fDstLatest, err := fs.NewFs(ctx, latestDir)
if err != nil {
return fmt.Errorf("failed to open destination %q: %w", latestDir, err)
}
fDstBackup, err := fs.NewFs(ctx, incrementDir)
if err != nil {
return fmt.Errorf("failed to initialize increment directory %q: %w", incrementDir, err)
}
// 2. Set BackupDir on the config context
ci.BackupDir = fDstBackup.Root()
if cfg.Verbose {
fmt.Printf("Starting sync from %s to %s with %d workers...\n",
cfg.Source, latestDir, cfg.Workers)
}
if err := sync.Sync(ctx, fDstLatest, fSrc, false); err != nil {
return fmt.Errorf("sync operation failed: %w", err)
}
// 3. Clean up the timestamp directory if nothing changed during sync
entries, err := fDstBackup.List(ctx, "")
if err == nil && len(entries) == 0 {
_ = operations.TryRmdir(ctx, fDstBackup, "")
if cfg.Verbose {
fmt.Println("No modifications detected; no increment folder created.")
}
} else if err == nil {
fmt.Printf("Created incremental snapshot: %s\n", incrementDir)
}
// 4. Prune excess incremental folders
if cfg.KeepIncrementals > 0 {
if err := pruneIncrementals(ctx, incrementsBase, cfg.KeepIncrementals, cfg.Verbose); err != nil {
return fmt.Errorf("retention pruning failed: %w", err)
}
}
return nil
}
func pruneIncrementals(ctx context.Context, incrementsPath string, keep int, verbose bool) error {
fIncrements, err := fs.NewFs(ctx, incrementsPath)
if err != nil {
return nil
}
entries, err := fIncrements.List(ctx, "")
if err != nil {
// If the folder hasn't been created yet, there is nothing to prune
if errors.Is(err, fs.ErrorDirNotFound) {
return nil
}
return err
}
var dirs []string
for _, entry := range entries {
if _, isDir := entry.(fs.Directory); isDir {
dirs = append(dirs, entry.Remote())
}
}
sort.Strings(dirs)
if len(dirs) <= keep {
return nil
}
excess := len(dirs) - keep
toDelete := dirs[:excess]
if verbose {
fmt.Printf("Pruning %d expired incremental snapshots (retention: %d)...\n", excess, keep)
}
for _, dirName := range toDelete {
subDirFs, err := fs.NewFs(ctx, filepath.Join(incrementsPath, dirName))
if err != nil {
continue
}
if err := operations.Purge(ctx, subDirFs, ""); err != nil {
return fmt.Errorf("failed to purge %s: %w", dirName, err)
}
if verbose {
fmt.Printf("Deleted snapshot: %s\n", dirName)
}
}
return nil
}