Docker stopped all of sudden in CentOS 7 -

i running docker on centos 7 machine. today trying upgrade container. stopped container , tried pull new image.

i got below error

error getting v2 registry: https://registry-1.docker.io/v2/: proxyconnect tcp: dial tcp: lookup https_proxy=http: no such host" 

i checked proxy setting machine in cat /etc/environment , docker in cat /etc/systemd/system/docker.service.d/http-proxy.conf

it set correctly. enabled daemon logs docker , logs says

sep 14 10:43:18 mycentosserver kernel: [4913751.074277] docker0: port 1(veth1e3300a) entered disabled state sep 14 10:43:18 mycentosserver kernel: [4913751.084599] docker0: port 1(veth1e3300a) entered disabled state sep 14 10:43:18 mycentosserver kernel: [4913751.084888] docker0: port 1(veth1e3300a) entered disabled state sep 14 10:43:18 mycentosserver networkmanager[794]: <info>  [1505349798.0267] device (veth1e3300a): released master device docker0 sep 14 10:44:48 mycentosserver dockerd[29136]: time="2017-09-14t10:44:48.802236300+10:00" level=warning msg="error getting v2 registry: https://registry-1.docker.io/v2/: proxyconnect tcp: dial tcp: lookup https_proxy=http: no such host" 

i tried below commands stuck.

systemctl daemon-reload systemctl restart docker 

any idea might issue.

thanks in advance.

it's occured in centos, can restart docker service systemctl restart docker.service