Using our stock iptables based on a default DROP policy, Dockerfiles based on Ubuntu or Debian are unable to resolve hosts on apt-get commands, making it impossible to build the files. If I change the default policy to ACCEPT it works as expected, so can confirm iptables is the problem. It's there a set of rules that need to be enabled for docker build to work? I've already allowed DNS port 53 INPUT/OUTPUT/FORWARD along with ports 80 and 443

  • Put logging entries in your firewall and see what turns up. – Michael Hampton Sep 7 '14 at 16:37

The issue was caused by iptables dropping a FORWARD from docker0 to eth0 See this blog post for more information

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