HTTP proxy configuration for Docker on CentOS 7

On CentOS7 if docker is behind a proxy server then use following steps:

Create folder for configuring docker service through systemd
```
mkdir /etc/systemd/system/docker.service.d
```

Create service configuration file at /etc/systemd/system/docker.service.d/http-proxy.conf

[Service]
Environment="HTTP_PROXY=http://proxy.iiit.ac.in:8080/" "NO_PROXY=localhost,127.0.0.0/8,10.0.0.0/8,192.168.0.0/16,172.16.0.0/12"

Reload systemctl so that new settings are read
```
sudo systemctl daemon-reload
```
Verify that docker service Environment is properly set
```
sudo systemctl show docker --property Environment
```
Restart docker service so that it uses updated Environment settings
```
sudo systemctl restart docker
```

Anonymous