dnsmasq-docker

Simple dns service using docker

Docker

build

git clone https://github.com/emuthiah/dnsmasq-docker.git
cd dnsmasq-docker
docker build -t dnsmasq:latest .

OR

Pull

docker pull emuthiah/dnsmasq

Run

docker run -it --rm --cap-add NET_ADMIN --name dnsmasq --dns 127.0.0.1 dnsmasq:latest

--cap-add NET_ADMIN is needed for dnsmasq to run, --dns 127.0.0.1 makes sure that container uses localhost dnsmasq for dns. This is also useful when other containers are attached to this containers network

Optional

Run container attached to dnsmasq network

docker run -it --rm --network container:dnsmasq --name ubuntu ubuntu:latest

Run container with dns pointing to dnsmasq container IP address

docker run -it --rm --dns <dnsmasq IP address> --name ubuntu ubuntu:latest

Find IP address of dnsmasq container

docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' dnsmasq

System

Update system network settings to use dnsmasq container IP address as dns server

DNS Queries

View container logs and grep for queries

docker logs dnsmasq --follow | grep "query\[.*\]" 

Output

dnsmasq[1]: query[A] docs.docker.com from 172.17.0.1
dnsmasq[1]: query[A] fonts.googleapis.com from 172.17.0.1
dnsmasq[1]: query[AAAA] docs.docker.com from 172.17.0.1
dnsmasq[1]: query[AAAA] fonts.googleapis.com from 172.17.0.1
dnsmasq[1]: query[A] www-googletagmanager.l.google.com from 172.17.0.1
dnsmasq[1]: query[AAAA] www-googletagmanager.l.google.com from 172.17.0.1