Use docker search over proxy on Centos 7

I was playing with docker little bit. After while I found out that I'm unable to interact with docker hub registry. Of course it is proxy. Again.

Error message at first:

[root@kra ~]$ docker search centos
2014/08/04 07:45:36 Error: Get https://index.docker.io/v1/search?q=centos:
dial tcp 107.22.52.107:443: connection refused

It looks like proxy issue. But how to fix it? After googling for a while I found out, that I could start docker daemon with proxy environmental variables. But docker daemon is started by systemd. So I looked into systemd configuration /usr/lib/systemd/system/docker.service:

[root@kra ~]$ cat /usr/lib/systemd/system/docker.service 
[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.io
After=network.target

[Service]
Type=notify
EnvironmentFile=-/etc/sysconfig/docker
ExecStart=/usr/bin/docker -d --selinux-enabled
Restart=on-failure
LimitNOFILE=1048576
LimitNPROC=1048576

[Install]
WantedBy=multi-user.target

There is definition of EnvironmentFile pointing to /etc/sysconfig/docker. File is empty:

[root@kra ~]$ cat /etc/sysconfig/docker 
# /etc/sysconfig/docker

I've put proxy environment variables there:

[root@kra ~]$ cat /etc/sysconfig/docker
# /etc/sysconfig/docker
http_proxy='http://user:password@proxy.somewhere.net:8080/'

After restarting docker daemon I've checked environment of docker process:

[root@kra ~]$ systemctl restart docker
[root@kra ~]$ ps -ef | grep docker
root      1977  1523  0 17:10 pts/2    00:00:00 grep --color=auto docker
root      3335     1  0 Jul30 ?        00:02:08 /usr/bin/docker -d --selinux-enabled
[root@kra ~]$ cat /proc/3335/environ 
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/binLANG=en_US.UTF-8NOTIFY_SOCKET=
@/org/freedesktop/systemd1/notifyhttp_proxy=http://user:password@proxy.somewhere.net:8080/[root@kra ~]$ 

And finally it is working:

[root@kra ~]$ docker search centos | head -n 5
NAME                 DESCRIPTION                                     STARS     OFFICIAL   TRUSTED
centos               The official build of CentOS.                   286       [OK]
tianon/centos        CentOS 5 and 6, created using rinse instea...   24
blalor/centos        Bare-bones base CentOS 6.5 image                5                    [OK]
tutum/centos-6.4     DEPRECATED. Use tutum/centos:6.4 instead. ...   5                    [OK]