Method writeLease

s3/leaser.go:231–266

(ctx context.Context, lease *litestream.Lease, etag string)

}

func (l *Leaser) writeLease(ctx context.Context, lease *litestream.Lease, etag string) (string, error) {
	key := l.lockKey()

	data, err := json.Marshal(lease)
	if err != nil {
		return "", fmt.Errorf("marshal lock file: %w", err)
	}

	input := &s3.PutObjectInput{
		Bucket:      aws.String(l.Bucket),
		Key:         aws.String(key),
		Body:        bytes.NewReader(data),
		ContentType: aws.String("application/json"),
	}

	if etag == "" {
		input.IfNoneMatch = aws.String("*")
	} else {
		input.IfMatch = aws.String(etag)
	}

	out, err := l.s3.PutObject(ctx, input)
	if err != nil {
		if isPreconditionFailed(err) {
			return "", &litestream.LeaseExistsError{}
		}
		return "", fmt.Errorf("put lock file: %w", err)
	}

	newETag := ""
	if out.ETag != nil {
		newETag = *out.ETag
	}

	return newETag, nil
}

func isPreconditionFailed(err error) bool {
	var apiErr smithy.APIError