[root@node2 ~]# docker --version                                                                                     
Docker version 1.12.6, build c4618fb/1.12.6

[root@node2 ~]# docker pull registry
Using default tag: latest
Trying to pull repository docker.io/library/registry ... 
latest: Pulling from docker.io/library/registry


90f4dba627d6: Pulling fs layer 
b3e11d7b4f5e: Pulling fs layer 
425585e7aedb: Waiting 
f45f535a83d2: Waiting 

error pulling image configuration: Get https://dseasb33srnrn.cloudfront.net/registry-v2/docker/registry/v2/blobs/sha256/28/28525f9a6e46bd6a033b3a3e5f5f64b28d93698b0a23cdb8d66b43b8d8e6b7c9/data?Expires=1506565630&Signature=K0Wu-U81DZM37w6nyV~SnDFGFTtzXQWpFHbwgrb5sAvVbfxgPZgS9cCYNsowHIog-2o681Vh~-520lKvLWLb~bLiwaORsVEeG8XDJ4AH4bffqDRpjBTQinNmWSifIMbIXoxh2Ii5IHTZtPvzzT67Z9or~V7CgkIHF8hTtpDAT-I_&Key-Pair-Id=APKAJECH5M7VWIS5YZ6Q: dial tcp: lookup dseasb33srnrn.cloudfront.net on 192.168.0.1:53: read udp 192.168.1.75:40503->192.168.0.1:53: i/o timeout

出现这个问题原因为国内网络问题，无法连接到 docker hub。 好在国内已经有  daocloud，docker指定该源即可。

centos7处理办法，其他系统版本处理方法类似，添加后重启docker ：

[root@node2 ~]# docker pull registry
Using default tag: latest
Trying to pull repository docker.io/library/registry ... 
latest: Pulling from docker.io/library/registry
90f4dba627d6: Pull complete 
b3e11d7b4f5e: Pull complete 
1f032f3c8932: Pull complete 
425585e7aedb: Pull complete 
f45f535a83d2: Pull complete 
Digest: sha256:0f8fe61fa337b8ef02217702ba979b47a7d68717d4628f31592ebff85915f3ba