Docker 1.10 access a container by its hostname from a host machine

As answered here there is a software solution for this, copying the answer:

There is an open source application that solves this issue, it's called DNS Proxy Server

It's a DNS server that resolves container hostnames, and when it can't resolve a hostname then it can resolve it using public nameservers.

Start the DNS Server

$ docker run --hostname dns.mageddo --name dns-proxy-server -p 5380:5380 \-v /var/run/docker.sock:/var/run/docker.sock \-v /etc/resolv.conf:/etc/resolv.conf \defreitas/dns-proxy-server

It will set as your default DNS automatically (and revert back to the original when it stops).

Start your container for the test

docker-compose up

docker-compose.yml

version: '2'services:  redis:    container_name: redis    image: redis:2.8    hostname: redis.dev.intranet    network_mode: bridge # that way he can solve others containers names even inside, solve elasticsearch, for example  elasticsearch:    container_name: elasticsearch    image: elasticsearch:2.2    hostname: elasticsearch.dev.intranet

Now resolve your containers' hostnames

from host

$ nslookup redis.dev.intranetServer:     172.17.0.2Address:    172.17.0.2#53Non-authoritative answer:Name:   redis.dev.intranetAddress: 172.21.0.3

from another container

$ docker exec -it redis ping elasticsearch.dev.intranetPING elasticsearch.dev.intranet (172.21.0.2): 56 data bytes

As well it resolves Internet hostnames

$ nslookup google.comServer:     172.17.0.2Address:    172.17.0.2#53Non-authoritative answer:Name:   google.comAddress: 216.58.202.78

Here's what I do.

I wrote a Python script called dnsthing, which listens to the Docker events API for containers starting or stopping. It maintains a hosts-style file with the names and addresses of containers. Containers are named <container_name>.<network>.docker, so for example if I run this:

docker run --rm --name mysql -e MYSQL_ROOT_PASSWORD=secret  mysql

I get this:

172.17.0.2 mysql.bridge.docker

I then run a dnsmasq process pointing at this hosts file. Specifically, I run a dnsmasq instance using the following configuration:

listen-address=172.31.255.253bind-interfacesaddn-hosts=/run/dnsmasq/docker.hostslocal=/docker/no-hostsno-resolv

And I run the dnsthing script like this:

dnsthing -c "systemctl restart dnsmasq_docker" \  -H /run/dnsmasq/docker.hosts --verbose

So:

• dnsthing updates /run/dnsmasq/docker.hosts as containersstop/start
• After an update, dnsthing runs systemctl restart dnsmasq_docker
• dnsmasq_docker runs dnsmasq using the above configuration, boundto a local bridge interface with the address 172.31.255.253.

• The "main" dnsmasq process on my system, maintained byNetworkManager, uses this configuration from/etc/NetworkManager/dnsmasq.d/dockerdns:

  server=/docker/172.31.255.253

  That tells dnsmasq to pass all requests for hosts in the .dockerdomain to the docker_dnsmasq service.

This obviously requires a bit of setup to put everything together, butafter that it seems to Just Work:

$ ping -c1  mysql.bridge.dockerPING mysql.bridge.docker (172.17.0.2) 56(84) bytes of data.64 bytes from 172.17.0.2: icmp_seq=1 ttl=64 time=0.087 ms--- mysql.bridge.docker ping statistics ---1 packets transmitted, 1 received, 0% packet loss, time 0msrtt min/avg/max/mdev = 0.087/0.087/0.087/0.000 ms

To specifically solve this problem I created a simple "etc/hosts" domain injection tool that resolves names of local Docker containers on the host. Just run:

docker run -d \    -v /var/run/docker.sock:/tmp/docker.sock \    -v /etc/hosts:/tmp/hosts \    --name docker-hoster \    dvdarias/docker-hoster

You will be able to access a container using the container name, hostname, container id and vía the network aliases they have declared for each network.

Containers are automatically registered when they start and removed when they are paused, dead or stopped.