Add support for ILM transition (#10565)

This PR adds transition support for ILM
to transition data to another MinIO target
represented by a storage class ARN. Subsequent
GET or HEAD for that object will be streamed from
the transition tier. If PostRestoreObject API is
invoked, the transitioned object can be restored for
duration specified to the source cluster.

cmd/erasure-metadata.go

@@ -142,6 +142,9 @@ func (fi FileInfo) ToObjectInfo(bucket, object string) ObjectInfo {
 	if fi.Deleted {
 		objInfo.ReplicationStatus = replication.StatusType(fi.DeleteMarkerReplicationStatus)
 	}
+
+	objInfo.TransitionStatus = fi.TransitionStatus
+
 	// etag/md5Sum has already been extracted. We need to
 	// remove to avoid it from appearing as part of
 	// response headers. e.g, X-Minio-* or X-Amz-*.
@@ -158,6 +161,11 @@ func (fi FileInfo) ToObjectInfo(bucket, object string) ObjectInfo {
 		objInfo.StorageClass = globalMinioDefaultStorageClass
 	}
 	objInfo.VersionPurgeStatus = fi.VersionPurgeStatus
+	// set restore status for transitioned object
+	if ongoing, exp, err := parseRestoreHeaderFromMeta(fi.Metadata); err == nil {
+		objInfo.RestoreOngoing = ongoing
+		objInfo.RestoreExpires = exp
+	}
 	// Success.
 	return objInfo
 }