I try create docker container with custom network and dos settings.
docker network create --driver=bridge --opt "com.docker.network.bridge.enable_ip_masquerade"="true" --opt "com.docker.network.bridge.enable_icc"="true" --opt="com.docker.network.driver.mtu"="1500" --opt="com.docker.network.bridge.host_binding_ipv4"="0.0.0.0" net
--
docker run --dns 10.0.0.2 --network=net busybox cat /etc/resolv.conf
nameserver 127.0.0.11
options ndots:0
Else if I use standard network all work fine
docker run --dns 10.0.0.2 --network=bridge busybox cat /etc/resolv.conf
nameserver 10.0.0.2
As of Docker 1.10, DNS is managed differently for user-defined networks. DNS for the default bridge network is unchanged for backwards compatibility. In a user-defined network, docker daemon uses the embedded DNS server. According to the documentation found here:
https://docs.docker.com/engine/userguide/networking/configure-dns/
--dns=[IP_ADDRESS...] The IP addresses passed via the --dns option is used by the embedded
DNS server to forward the DNS query if embedded DNS server is unable
to resolve a name resolution request from the containers. These
--dns IP addresses are managed by the embedded DNS server and will not
be updated in the container’s /etc/resolv.conf file.
So, the DNS nameserver will be used, it just is not visible in the container's /etc/resolv.conf.
