A recent change to prevent containers only connected to --internal
networks from communicating with external DNS servers inadvertently
prevented the daemon's internal DNS server from forwarding requests
within an internal network to a containerised DNS server.
Relax the check, so that only requests that need to be forwarded
from the host's network namespace are dropped.
External DNS servers remain unreachable from the internal network.
Signed-off-by: Rob Murray <rob.murray@docker.com>
(cherry picked from commit 77a47dba3b)
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Libnetwork provides a native Go implementation for connecting containers
The goal of libnetwork is to deliver a robust Container Network Model that provides a consistent programming interface and the required network abstractions for applications.
There are many networking solutions available to suit a broad range of use-cases. libnetwork uses a driver / plugin model to support all of these solutions while abstracting the complexity of the driver implementations by exposing a simple and consistent Network Model to users.