s3api: preserve lifecycle config responses for Terraform (#8805)

* s3api: preserve lifecycle configs for terraform

* s3api: bound lifecycle config request bodies

* s3api: make bucket config updates copy-on-write

* s3api: tighten string slice cloning

weed/s3api/s3api_bucket_lifecycle_config.go

@@ -0,0 +1,75 @@
+package s3api
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/seaweedfs/seaweedfs/weed/s3api/s3err"
+)
+
+const (
+	bucketLifecycleConfigurationXMLKey               = "s3-bucket-lifecycle-configuration-xml"
+	bucketLifecycleTransitionMinimumObjectSizeKey    = "s3-bucket-lifecycle-transition-default-minimum-object-size"
+	bucketLifecycleTransitionMinimumObjectSizeHeader = "X-Amz-Transition-Default-Minimum-Object-Size"
+	defaultLifecycleTransitionMinimumObjectSize      = "all_storage_classes_128K"
+	maxBucketLifecycleConfigurationSize              = 1 << 20
+)
+
+func normalizeBucketLifecycleTransitionMinimumObjectSize(value string) string {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return defaultLifecycleTransitionMinimumObjectSize
+	}
+	return value
+}
+
+func (s3a *S3ApiServer) getStoredBucketLifecycleConfiguration(bucket string) ([]byte, string, bool, s3err.ErrorCode) {
+	config, errCode := s3a.getBucketConfig(bucket)
+	if errCode != s3err.ErrNone {
+		return nil, "", false, errCode
+	}
+	if config.Entry == nil || config.Entry.Extended == nil {
+		return nil, "", false, s3err.ErrNone
+	}
+
+	lifecycleXML, found := config.Entry.Extended[bucketLifecycleConfigurationXMLKey]
+	if !found || len(lifecycleXML) == 0 {
+		return nil, "", false, s3err.ErrNone
+	}
+
+	transitionMinimumObjectSize := normalizeBucketLifecycleTransitionMinimumObjectSize(
+		string(config.Entry.Extended[bucketLifecycleTransitionMinimumObjectSizeKey]),
+	)
+
+	return append([]byte(nil), lifecycleXML...), transitionMinimumObjectSize, true, s3err.ErrNone
+}
+
+func (s3a *S3ApiServer) storeBucketLifecycleConfiguration(bucket string, lifecycleXML []byte, transitionMinimumObjectSize string) s3err.ErrorCode {
+	return s3a.updateBucketConfig(bucket, func(config *BucketConfig) error {
+		if config.Entry == nil {
+			return fmt.Errorf("bucket %s is missing its filer entry", bucket)
+		}
+		if config.Entry.Extended == nil {
+			config.Entry.Extended = make(map[string][]byte)
+		}
+
+		config.Entry.Extended[bucketLifecycleConfigurationXMLKey] = append([]byte(nil), lifecycleXML...)
+		config.Entry.Extended[bucketLifecycleTransitionMinimumObjectSizeKey] = []byte(
+			normalizeBucketLifecycleTransitionMinimumObjectSize(transitionMinimumObjectSize),
+		)
+
+		return nil
+	})
+}
+
+func (s3a *S3ApiServer) clearStoredBucketLifecycleConfiguration(bucket string) s3err.ErrorCode {
+	return s3a.updateBucketConfig(bucket, func(config *BucketConfig) error {
+		if config.Entry == nil {
+			return fmt.Errorf("bucket %s is missing its filer entry", bucket)
+		}
+
+		delete(config.Entry.Extended, bucketLifecycleConfigurationXMLKey)
+		delete(config.Entry.Extended, bucketLifecycleTransitionMinimumObjectSizeKey)
+		return nil
+	})
+}