Add tool to migrate data from badger to mysql or postgresql

scripts/README.md

@@ -2,3 +2,7 @@
 
 Please note that `install-step-ra.sh` is referenced on the `files.smallstep.com` S3 website bucket as a redirect to `raw.githubusercontent.com`. If you move it, please update the S3 redirect.
 
+## badger-migration
+
+badger-migration is a tool that allows to migrate data from a BadgerDB (v1 or
+v2) to MySQL or PostgreSQL.

scripts/badger-migration/main.go

@@ -0,0 +1,326 @@
+package main
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+
+	badgerv1 "github.com/dgraph-io/badger"
+	badgerv2 "github.com/dgraph-io/badger/v2"
+
+	"github.com/smallstep/nosql"
+)
+
+var (
+	authorityTables = []string{
+		"x509_certs",
+		"x509_certs_data",
+		"revoked_x509_certs",
+		"x509_crl",
+		"revoked_ssh_certs",
+		"used_ott",
+		"ssh_certs",
+		"ssh_hosts",
+		"ssh_users",
+		"ssh_host_principals",
+	}
+	acmeTables = []string{
+		"acme_accounts",
+		"acme_keyID_accountID_index",
+		"acme_authzs",
+		"acme_challenges",
+		"nonces",
+		"acme_orders",
+		"acme_account_orders_index",
+		"acme_certs",
+		"acme_serial_certs_index",
+		"acme_external_account_keys",
+		"acme_external_account_keyID_reference_index",
+		"acme_external_account_keyID_provisionerID_index",
+	}
+)
+
+func usage(fs *flag.FlagSet) {
+	name := filepath.Base(os.Args[0])
+	fmt.Fprintf(os.Stderr, "%s is a tool to migrate Badger databases to MySQL or PostgreSQL.\n", name)
+	fmt.Fprintln(os.Stderr, "\nUsage:")
+	fmt.Fprintf(os.Stderr, "  %s [-v1|-v2] -dir=<path> [-value-dir=<path>] -type=type -database=<source>\n", name)
+	fmt.Fprintln(os.Stderr, "\nExamples:")
+	fmt.Fprintf(os.Stderr, "  %s -v1 -dir /var/lib/step-ca/db -type=mysql -database \"user@unix/step_ca\"\n", name)
+	fmt.Fprintf(os.Stderr, "  %s -v2 -dir /var/lib/step-ca/db -type=mysql -database \"user:password@tcp(localhost:3306)/step_ca\"\n", name)
+	fmt.Fprintf(os.Stderr, "  %s -v2 -dir /var/lib/step-ca/db -type=postgresql --database \"user=postgres dbname=step_ca\"\n", name)
+	fmt.Fprintln(os.Stderr, "\nOptions:")
+	fs.PrintDefaults()
+}
+
+func main() {
+	var v1, v2 bool
+	var dir, valueDir string
+	var typ, database string
+
+	fs := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+
+	fs.BoolVar(&v1, "v1", false, "use badger v1 as the source database")
+	fs.BoolVar(&v2, "v2", true, "use badger v2 as the source database")
+	fs.StringVar(&dir, "dir", "", "badger database directory")
+	fs.StringVar(&valueDir, "value-dir", "", "badger database value directory")
+	fs.StringVar(&typ, "type", "", "the destination database type to use")
+	fs.StringVar(&database, "database", "", "the destination driver-specific data source name")
+	fs.Usage = func() { usage(fs) }
+	fs.Parse(os.Args[1:])
+
+	switch {
+	case v1 == v2:
+		fatal("flag --v1 or --v2 are required")
+	case dir == "":
+		fatal("flag --dir is required")
+	case typ != "postgresql" && typ != "mysql":
+		fatal(`flag --type must be "postgresql" or "mysql"`)
+	case database == "":
+		fatal("flag --database required")
+	}
+
+	var (
+		err  error
+		v1DB *badgerv1.DB
+		v2DB *badgerv2.DB
+	)
+
+	if v1 {
+		if v1DB, err = badgerV1Open(dir, valueDir); err != nil {
+			fatal("error opening badger v2 database: %v", err)
+		}
+	} else {
+		if v2DB, err = badgerV2Open("/tmp/db", ""); err != nil {
+			fatal("error opening badger v2 database: %v", err)
+		}
+	}
+
+	db, err := nosql.New(typ, database)
+	if err != nil {
+		fatal("error opening %s database: %v", typ, err)
+	}
+
+	allTables := append([]string{}, authorityTables...)
+	allTables = append(allTables, acmeTables...)
+
+	for _, table := range allTables {
+		var n int64
+		fmt.Printf("migrating %s ...\n", table)
+		if err := db.CreateTable([]byte(table)); err != nil {
+			fatal("error creating table %s: %v", table, err)
+		}
+
+		if v1 {
+			if err := badgerV1Iterate(v1DB, []byte(table), func(bucket, key, value []byte) error {
+				n++
+				return db.Set(bucket, key, value)
+			}); err != nil {
+				fatal("error inserting into %s: %v", table, err)
+			}
+		} else {
+			if err := badgerV2Iterate(v2DB, []byte(table), func(bucket, key, value []byte) error {
+				n++
+				return db.Set(bucket, key, value)
+			}); err != nil {
+				fatal("error inserting into %s: %v", table, err)
+			}
+		}
+
+		log.Printf("%d rows\n", n)
+	}
+}
+
+func fatal(format string, args ...any) {
+	fmt.Fprintf(os.Stderr, format, args...)
+	fmt.Fprintln(os.Stderr)
+	os.Exit(1)
+}
+
+func badgerV1Open(dir, valueDir string) (*badgerv1.DB, error) {
+	opts := badgerv1.DefaultOptions(dir)
+	if valueDir != "" {
+		opts.ValueDir = valueDir
+	}
+	return badgerv1.Open(opts)
+}
+
+func badgerV2Open(dir, valueDir string) (*badgerv2.DB, error) {
+	opts := badgerv2.DefaultOptions(dir)
+	if valueDir != "" {
+		opts.ValueDir = valueDir
+	}
+	return badgerv2.Open(opts)
+}
+
+func badgerV1Iterate(db *badgerv1.DB, table []byte, fn func(table, key, value []byte) error) error {
+	return db.View(func(txn *badgerv1.Txn) error {
+		var tableExists bool
+
+		it := txn.NewIterator(badgerv1.DefaultIteratorOptions)
+		defer it.Close()
+
+		prefix, err := badgerEncode(table)
+		if err != nil {
+			return err
+		}
+
+		for it.Seek(prefix); it.ValidForPrefix(prefix); it.Next() {
+			tableExists = true
+			item := it.Item()
+			bk := item.KeyCopy(nil)
+			if isBadgerTable(bk) {
+				continue
+			}
+
+			bucket, key, err := fromBadgerKey(bk)
+			if err != nil {
+				return fmt.Errorf("error converting from badger key %s", bk)
+			}
+			if !bytes.Equal(table, bucket) {
+				return fmt.Errorf("bucket names do not match; want %s, but got %s", table, bucket)
+			}
+
+			v, err := item.ValueCopy(nil)
+			if err != nil {
+				return fmt.Errorf("error retrieving contents from database value: %w", err)
+			}
+			value := cloneBytes(v)
+
+			if err := fn(bucket, key, value); err != nil {
+				return fmt.Errorf("error exporting %s[%s]=%v", table, key, value)
+			}
+		}
+
+		if !tableExists {
+			fmt.Printf("bucket %s not found\n", table)
+		}
+
+		return nil
+	})
+}
+
+func badgerV2Iterate(db *badgerv2.DB, table []byte, fn func(table, key, value []byte) error) error {
+	return db.View(func(txn *badgerv2.Txn) error {
+		var tableExists bool
+
+		it := txn.NewIterator(badgerv2.DefaultIteratorOptions)
+		defer it.Close()
+
+		prefix, err := badgerEncode(table)
+		if err != nil {
+			return err
+		}
+		for it.Seek(prefix); it.ValidForPrefix(prefix); it.Next() {
+			tableExists = true
+			item := it.Item()
+			bk := item.KeyCopy(nil)
+			if isBadgerTable(bk) {
+				continue
+			}
+
+			bucket, key, err := fromBadgerKey(bk)
+			if err != nil {
+				return fmt.Errorf("error converting from badgerKey %s: %w", bk, err)
+			}
+			if !bytes.Equal(table, bucket) {
+				return fmt.Errorf("bucket names do not match; want %s, but got %s", table, bucket)
+			}
+
+			v, err := item.ValueCopy(nil)
+			if err != nil {
+				return fmt.Errorf("error retrieving contents from database value: %w", err)
+			}
+			value := cloneBytes(v)
+
+			if err := fn(bucket, key, value); err != nil {
+				return fmt.Errorf("error exporting %s[%s]=%v", table, key, value)
+			}
+		}
+		if !tableExists {
+			log.Printf("bucket %s not found", table)
+		}
+		return nil
+	})
+}
+
+// badgerEncode encodes a byte slice into a section of a BadgerKey.
+// See documentation for toBadgerKey.
+func badgerEncode(val []byte) ([]byte, error) {
+	l := len(val)
+	switch {
+	case l == 0:
+		return nil, errors.New("input cannot be empty")
+	case l > 65535:
+		return nil, errors.New("length of input cannot be greater than 65535")
+	default:
+		lb := new(bytes.Buffer)
+		if err := binary.Write(lb, binary.LittleEndian, uint16(l)); err != nil {
+			return nil, fmt.Errorf("error doing binary Write: %w", err)
+		}
+		return append(lb.Bytes(), val...), nil
+	}
+}
+
+// isBadgerTable returns True if the slice is a badgerTable token, false otherwise.
+// badgerTable means that the slice contains only the [size|value] of one section
+// of a badgerKey and no remainder. A badgerKey is [buket|key], while a badgerTable
+// is only the bucket section.
+func isBadgerTable(bk []byte) bool {
+	if k, rest := parseBadgerEncode(bk); len(k) > 0 && len(rest) == 0 {
+		return true
+	}
+	return false
+}
+
+// fromBadgerKey returns the bucket and key encoded in a BadgerKey.
+// See documentation for toBadgerKey.
+func fromBadgerKey(bk []byte) ([]byte, []byte, error) {
+	bucket, rest := parseBadgerEncode(bk)
+	if len(bucket) == 0 || len(rest) == 0 {
+		return nil, nil, fmt.Errorf("invalid badger key: %v", bk)
+	}
+
+	key, rest2 := parseBadgerEncode(rest)
+	if len(key) == 0 || len(rest2) != 0 {
+		return nil, nil, fmt.Errorf("invalid badger key: %v", bk)
+	}
+
+	return bucket, key, nil
+}
+
+// cloneBytes returns a copy of a given slice.
+func cloneBytes(v []byte) []byte {
+	var clone = make([]byte, len(v))
+	copy(clone, v)
+	return clone
+}
+
+func parseBadgerEncode(bk []byte) (value, rest []byte) {
+	var (
+		keyLen uint16
+		start  = uint16(2)
+		length = uint16(len(bk))
+	)
+	if uint16(len(bk)) < start {
+		return nil, bk
+	}
+	// First 2 bytes stores the length of the value.
+	if err := binary.Read(bytes.NewReader(bk[:2]), binary.LittleEndian, &keyLen); err != nil {
+		return nil, bk
+	}
+	end := start + keyLen
+	switch {
+	case length < end:
+		return nil, bk
+	case length == end:
+		return bk[start:end], nil
+	default:
+		return bk[start:end], bk[end:]
+	}
+}