snapshot of https://github.com/golang-migrate/migrate.git (master, 2026-09-15; blobs > 131072B omitted)

source/aws_s3/s3.go

@@ -0,0 +1,160 @@
+package awss3
+
+import (
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/s3"
+	"github.com/aws/aws-sdk-go/service/s3/s3iface"
+	"github.com/golang-migrate/migrate/v4/source"
+)
+
+func init() {
+	source.Register("s3", &s3Driver{})
+}
+
+type s3Driver struct {
+	s3client   s3iface.S3API
+	config     *Config
+	migrations *source.Migrations
+}
+
+type Config struct {
+	Bucket string
+	Prefix string
+}
+
+func (s *s3Driver) Open(folder string) (source.Driver, error) {
+	config, err := parseURI(folder)
+	if err != nil {
+		return nil, err
+	}
+
+	sess, err := session.NewSession()
+	if err != nil {
+		return nil, err
+	}
+
+	return WithInstance(s3.New(sess), config)
+}
+
+func WithInstance(s3client s3iface.S3API, config *Config) (source.Driver, error) {
+	driver := &s3Driver{
+		config:     config,
+		s3client:   s3client,
+		migrations: source.NewMigrations(),
+	}
+
+	if err := driver.loadMigrations(); err != nil {
+		return nil, err
+	}
+
+	return driver, nil
+}
+
+func parseURI(uri string) (*Config, error) {
+	u, err := url.Parse(uri)
+	if err != nil {
+		return nil, err
+	}
+
+	prefix := strings.Trim(u.Path, "/")
+	if prefix != "" {
+		prefix += "/"
+	}
+
+	return &Config{
+		Bucket: u.Host,
+		Prefix: prefix,
+	}, nil
+}
+
+func (s *s3Driver) loadMigrations() error {
+	input := &s3.ListObjectsInput{
+		Bucket:    aws.String(s.config.Bucket),
+		Prefix:    aws.String(s.config.Prefix),
+		Delimiter: aws.String("/"),
+	}
+	// ListObjects returns at most 1000 keys per response, so paginate over
+	// every page; otherwise migrations beyond the first 1000 objects are
+	// silently dropped and never applied.
+	var appendErr error
+	err := s.s3client.ListObjectsPages(input, func(output *s3.ListObjectsOutput, _ bool) bool {
+		for _, object := range output.Contents {
+			_, fileName := path.Split(aws.StringValue(object.Key))
+			m, err := source.DefaultParse(fileName)
+			if err != nil {
+				continue
+			}
+			if !s.migrations.Append(m) {
+				appendErr = fmt.Errorf("unable to parse file %v", aws.StringValue(object.Key))
+				return false
+			}
+		}
+		return true
+	})
+	if err != nil {
+		return err
+	}
+	return appendErr
+}
+
+func (s *s3Driver) Close() error {
+	return nil
+}
+
+func (s *s3Driver) First() (uint, error) {
+	v, ok := s.migrations.First()
+	if !ok {
+		return 0, os.ErrNotExist
+	}
+	return v, nil
+}
+
+func (s *s3Driver) Prev(version uint) (uint, error) {
+	v, ok := s.migrations.Prev(version)
+	if !ok {
+		return 0, os.ErrNotExist
+	}
+	return v, nil
+}
+
+func (s *s3Driver) Next(version uint) (uint, error) {
+	v, ok := s.migrations.Next(version)
+	if !ok {
+		return 0, os.ErrNotExist
+	}
+	return v, nil
+}
+
+func (s *s3Driver) ReadUp(version uint) (io.ReadCloser, string, error) {
+	if m, ok := s.migrations.Up(version); ok {
+		return s.open(m)
+	}
+	return nil, "", os.ErrNotExist
+}
+
+func (s *s3Driver) ReadDown(version uint) (io.ReadCloser, string, error) {
+	if m, ok := s.migrations.Down(version); ok {
+		return s.open(m)
+	}
+	return nil, "", os.ErrNotExist
+}
+
+func (s *s3Driver) open(m *source.Migration) (io.ReadCloser, string, error) {
+	key := path.Join(s.config.Prefix, m.Raw)
+	object, err := s.s3client.GetObject(&s3.GetObjectInput{
+		Bucket: aws.String(s.config.Bucket),
+		Key:    aws.String(key),
+	})
+	if err != nil {
+		return nil, "", err
+	}
+	return object.Body, m.Identifier, nil
+}