relateiq/node-docker-machine-dns

Name: node-docker-machine-dns

Owner: SalesforceIQ

Description: Runs a tiny A-Record DNS server that runs hostnames thru $(docker-machine ip NAME) to resolve

Created: 2015-10-08 19:43:28.0

Updated: 2018-05-13 14:56:49.0

Pushed: 2016-06-01 18:41:15.0

Homepage: null

Size: 16

Language: JavaScript

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README

docker-machine DNS server

This package fires up a tiny (~100 lines) DNS server whose sole purpose is to listen for *.docker DNS lookups and resolve the hostname using docker-machine ip.

How it works:

• DNS query for dev.docker comes in
• Server parses out “dev.docker”
• Server responds with the result of $(docker-machine ip dev)

Environment variables

DOCKER_MACHINE_DNS_RESOLVER

Change the default IP resolver from docker-machine ip to your own custom command by setting this environment variable.

DOCKER_MACHINE_DNS_TLD

Change the default tld from docker by setting this environment variable.

Setup:

Install in the usual way:

install -g docker-machine-dns

Setup: The easy way

Run this:

 mkdir -p /etc/resolver
 touch /etc/resolver/docker
 chown -R $USER /etc/resolver       

This creates the /etc/resolver directory (if it doesn't already exist) and grants ownership to your current user account. The service will automatically configure the resolver/docker file on each run, making it “just work”.

Setup: The way that doesn't require changing ownership of /etc/resolver

Write this to /etc/resolver/docker and always run with the same specified port

server  127.0.0.1
    12345
ch_order    300000
out 1

Note: the whitespace separators in this file NEED to be tabs. Spaces won't work.

Example:

cker-machine ls
   ACTIVE   DRIVER       STATE     URL                         SWARM
            virtualbox   Running   tcp://192.168.99.100:2376
            virtualbox   Running   tcp://192.168.99.101:2376
            virtualbox   Stopped

ng -t 4 dev.docker
: cannot resolve dev.docker: Unknown host

cker-machine-dns &
18007
ening on UDP port 55451

ng -t 4 dev.docker
 dev.docker (192.168.99.100): 56 data bytes
ytes from 192.168.99.100: icmp_seq=0 ttl=64 time=0.268 ms
ytes from 192.168.99.100: icmp_seq=1 ttl=64 time=0.272 ms
ytes from 192.168.99.100: icmp_seq=2 ttl=64 time=0.313 ms
ytes from 192.168.99.100: icmp_seq=3 ttl=64 time=0.454 ms

dev.docker ping statistics ---
ckets transmitted, 4 packets received, 0.0% packet loss
d-trip min/avg/max/stddev = 0.268/0.327/0.454/0.076 ms

ng -t 4 dev2.docker
 dev2.docker (192.168.99.101): 56 data bytes
ytes from 192.168.99.101: icmp_seq=0 ttl=64 time=0.232 ms
ytes from 192.168.99.101: icmp_seq=1 ttl=64 time=0.394 ms
ytes from 192.168.99.101: icmp_seq=2 ttl=64 time=0.284 ms
ytes from 192.168.99.101: icmp_seq=3 ttl=64 time=0.222 ms

dev2.docker ping statistics ---
ckets transmitted, 4 packets received, 0.0% packet loss
d-trip min/avg/max/stddev = 0.222/0.283/0.394/0.068 ms

docker-machine-dns can take a UDP port as its first (and only) argument to bind to that specific port instead of randomly picking one on each run.