queryable

queryable

Inspired by the guys over at GliderLabs (even the name) and the resolvable project, the main resolver code is from that project, a few minor changes were made for default upstream recursors and additional logging.

The purpose of this project is to provide local DNS for docker containers. Containers are discoverable via .docker domain by default.

Like resolvable this honors the DNS_RESOLVES and DNS_PORT env vars that containers can set, like consul. If a container has DNS_RESOLVES=consul an upstream nameserver will be registered for all queries that end in consul.

I also instrumented the code using codegansta/cli for CLI options.

Options

• --recursor
• --host-ip
• --port
• --domain

Example

You just want to be able to discover local docker containers by their friendly name or container id.

docker run -d \
  --name queryable \
  --restart always \
  -p 0.0.0.0:53:53/udp \
  -v /var/run/docker.sock:/tmp/docker.sock \
  ekristen/queryable \
  --recursor 8.8.8.8

You can then update the /etc/resolv.conf and point to eth0 or docker0 IP address for DNS, all containers will get this by default then. OR you can modify the docker defaults to set --dns to either option.

DNS Entry Examples

All the sub items can be used via DNS to get the IP.

• id: 5df839803dc0250747baa81fb192ca301d91c5c9b5e18420c53956896c710358, name: focused_poincare, ip: 172.17.0.10
  • 5df839803dc0
  • focused_poincare
  • focused_poincare.DOMAIN

Credits

The main credit goes to Matt Good and GliderLabs and their resolvable project.

The resolvable project is licensed under MIT, as is this project.