Problem:
Error response from daemon: Get https://index.docker.io/v1/search?q=ubuntu: dial tcp: lookup index.docker.io: no DNS servers
Answer 1:
add name server 127.0.0.1 to /etc/resolv.conf
vim /etc/resolv.conf
nameserver 127.0.0.1
nameserver 8.8.8.8
service docker restart
Answer 2:
add name server 127.0.0.1 to /etc/network/interfaces
vim /etc/network/interfaces
dns-nameservers 127.0.0.1
ifdown eth0 && ifup eth0
service docker restart
