当前版本
[root@localhost ~]# docker version
Client version: 1.7.1
Client API version: 1.19
Go version (client): go1.4.2
Git commit (client): 786b29d/1.7.1
OS/Arch (client): linux/amd64
Server version: 1.7.1
Server API version: 1.19
Go version (server): go1.4.2
Git commit (server): 786b29d/1.7.1
OS/Arch (server): linux/amd64
1、问题：
Error response from daemon: invalid registry endpoint unable to ping registry endpoint
v2 ping attempt failed with error: Get tls: oversized record received with length 28012
v1 ping attempt failed with error: Get tls: oversized record received with length 28012. If this private registry supports only HTTP or HTTPS with an unknown CA certificate, please add `--insecure-registry dl.dockerpool.com:5000` to the daemon's arguments. In the case of HTTPS, if you have access to the registry's CA certificate, no need for the flag; simply place the CA certificate at /etc/docker/certs.d/dl.dockerpool.com:5000/ca.crt
解决：修改文件：/etc/sysconfig/docker 中other_args参数
other_args='--selinux-enabled --insecure-registry dl.dockerpool.com:5000'