Similar things happen in the output of radosgw-admin object stat, some strings are shown with a trailing \u0000:
$ radosgw-admin object stat --bucket=bla --object=test3
{
"name": "test3",
"size": 524832,
"policy": {
"acl": {
"acl_user_map": [
{
"user": "testuser",
"acl": 15
}
],
"acl_group_map": [],
"grant_map": [
{
"id": "testuser",
"grant": {
"type": {
"type": 0
},
"id": "testuser",
"email": "",
"permission": {
"flags": 15
},
"name": "First User",
"group": 0
}
}
]
},
"owner": {
"id": "testuser",
"display_name": "First User"
}
},
"etag": "fc6cd955f73309491281e260fb3a3ec7\u0000",
"tag": "default.4185.25\u0000",
"manifest": {
"objs": [],
"obj_size": 524832,
"explicit_objs": "false",
"head_obj": {
"bucket": {
"name": "bla",
"pool": ".rgw.buckets",
"data_extra_pool": ".rgw.buckets.extra",
"index_pool": ".rgw.buckets.index",
"marker": "default.4181.1",
"bucket_id": "default.4181.1"
},
"key": "",
"ns": "",
"object": "test3",
"instance": ""
},
"head_size": 524288,
"max_head_size": 524288,
"prefix": ".HMardeFI8bkByiZcoNTTz4vPa2nnVrN_",
"tail_bucket": {
"name": "bla",
"pool": ".rgw.buckets",
"data_extra_pool": ".rgw.buckets.extra",
"index_pool": ".rgw.buckets.index",
"marker": "default.4181.1",
"bucket_id": "default.4181.1"
},
"rules": [
{
"key": 0,
"val": {
"start_part_num": 0,
"start_ofs": 524288,
"part_size": 0,
"stripe_max_size": 4194304,
"override_prefix": ""
}
}
]
},
"attrs": {
"user.rgw.content_type": "binary\/octet-stream\u0000",
"user.rgw.x-amz-date": "Thu, 01 Jun 2017 08:36:53 +0000\u0000"
}
}