stat: Return additional header for deletemarker replication (#1707)

that indicates whether target is ready to receive deletemarker.

api-datatypes.go

@@ -147,7 +147,8 @@ type ObjectInfo struct {
 	// - FAILED
 	// - REPLICA (on the destination)
 	ReplicationStatus string `xml:"ReplicationStatus"`
-
+	// set to true if delete marker has backing object version on target, and eligible to replicate
+	ReplicationReady bool
 	// Lifecycle expiry-date and ruleID associated with the expiry
 	// not to be confused with `Expires` HTTP header.
 	Expiration       time.Time

api-stat.go

@@ -90,6 +90,7 @@ func (c *Client) StatObject(ctx context.Context, bucketName, objectName string,
 
 	if resp != nil {
 		deleteMarker := resp.Header.Get(amzDeleteMarker) == "true"
+		replicationReady := resp.Header.Get(minioTgtReplicationReady) == "true"
 		if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusPartialContent {
 			if resp.StatusCode == http.StatusMethodNotAllowed && opts.VersionID != "" && deleteMarker {
 				errResp := ErrorResponse{
@@ -105,8 +106,9 @@ func (c *Client) StatObject(ctx context.Context, bucketName, objectName string,
 				}, errResp
 			}
 			return ObjectInfo{
-				VersionID:      resp.Header.Get(amzVersionID),
-				IsDeleteMarker: deleteMarker,
+				VersionID:        resp.Header.Get(amzVersionID),
+				IsDeleteMarker:   deleteMarker,
+				ReplicationReady: replicationReady, // whether delete marker can be replicated
 			}, httpRespToErrorResponse(resp, bucketName, objectName)
 		}
 	}

constants.go

@@ -96,6 +96,7 @@ const (
 	minIOBucketReplicationObjectRetentionTimestamp = "X-Minio-Source-Replication-Retention-Timestamp"
 	// Header indicates last legalhold update time on source
 	minIOBucketReplicationObjectLegalHoldTimestamp = "X-Minio-Source-Replication-LegalHold-Timestamp"
-
-	minIOForceDelete = "x-minio-force-delete"
+	minIOForceDelete                               = "x-minio-force-delete"
+	// Header indicates delete marker replication request can be sent by source now.
+	minioTgtReplicationReady = "X-Minio-Replication-Ready"
 )