docker 注册表 ping 404

docker registry ping 404

我已经使用

创建了一个 docker 注册表 
docker run
-e SETTINGS_FLAVOR=s3
-e STORAGE_PATH=/registry
-e SEARCH_BACKEND=sqlalchemy
-p 5000:5000 
registry

并通过 ping 变为

172.17.0.1 - - [18/Jun/2017:17:56:47 +0000] "GET /v2/_ping HTTP/1.1" 404 19 "" ""

但我可以推送和拉取图像。

https://github.com/docker/distribution/issues/994

The ping endpoint for the registry is /v2/ not /v2/_ping