Problem

We need a dns but not on port 53. If you tried to install a dnsmasq on the machine directly and use a port other than 53, your'd find it makes your server unable to resolve dns normally. Yes we have stuff like iptables. However, I can never remember it's parameters...

So, why not use docker?

Steps:

1. Install docker

https://docs.docker.com/engine/installation/linux/docker-ce/ubuntu/

2. Get image (use port 27777)

docker run -d -p 27777:53/tcp -p 27777:53/udp --cap-add=NET_ADMIN --name dns-server andyshinn/dnsmasq:2.75

3. Revise upstream dns server

docker exec -it dns-server /bin/sh
vi /etc/dnsmasq.conf

• Add to dnsmasq.conf:

server=8.8.8.8
server=208.67.222.222

4. Restart

docker restart dns-server

End, easy!