Run docker containers without fuss

Sick and tired of having to setup coreOS, dokku, beanstalk, whatever?

Try this

npm install -g dock

Make sure the DOCKER_HOST env variable is set (otherwise we guess you are using the default UNIX socket).

Now, run the container proxy:

» node dude.js                                                                                                                                                 
DOCKER HOST => 192.168.59.103
Proxy listening on port 3000
containers:

So, no containers running on this docker instance (192.168.59.103) and the proxy is listening on localhost:3000.

Lets start a container in the foreground (this will pull nginx from the docker repo)

docker run --rm --name nginx -P nginx

The proxy should indicate the container is mapped

containers: nginx

Let's test it out

» http nginx.dev:3000                                                                                                                                        	HTTP/1.1 200 OK
connection: close
...
<p><em>Thank you for using nginx.</em></p>
</body>
</html>

Ok that works. Now when you C^c the docker run --rm command, this stops and removes the container. The proxy output should update again.

Now, trying to access nginx again gives an error:

~/r/D/dock » http nginx.dev:3000                                                                                                                                           
HTTP/1.1 404 Not Found
Connection: keep-alive
Content-Type: text/plain
Date: Wed, 26 Nov 2014 03:34:35 GMT
Transfer-Encoding: chunked

No container with public ports found for hostname 'nginx.dev'	

That's it. Easy no?

Running containers

You need a docker host

On OSX for development using boot2docker

See [[Docker]] for details, but TL;DR

brew install boot2docker
boot2docker upgrade

The following command prints some shell script you should run to set some environment vars. boot2docker shellinit 2> /dev/null

The host should now be reachable, try it

docker ps

Debian production

I guess it's

apt-get install docker

Run existing container

This should start nginx

docker run --rm --name nginx -P nginx

Your host is now accessible at

http://nginx.dev/

Build and run custom docker image

TL;DR (see [[Docker]] for more info)

docker build --no-cache --rm -t testlab/something .
docker images
docker ps
docker run --rm --name something -P testlab/something

This is now accessible at

http://something.dev/

(Or any subdomain that starts with the name of the container)

Work with .dev hostnames mapping to 127.0.0.1.

Install dnsmasq to cache DNS queries and resolve *.localhost.com to 127.0.0.1

brew install dnsmasq

Add DNS entry for localhost.com to /usr/local/etc/dnsmasq.conf

echo "address=/dev/127.0.0.1" > /usr/local/etc/dnsmasq.conf

Install launchdeamon and load dnsmasq now

sudo cp -fv /usr/local/opt/dnsmasq/*.plist /Library/LaunchDaemons
sudo chown root /Library/LaunchDaemons/homebrew.mxcl.dnsmasq.plist
sudo launchctl load /Library/LaunchDaemons/homebrew.mxcl.dnsmasq.plist

If you made a mistake in the configuration, use the following commands after changing the conf to restart dnsmasq

# stop might actually also start it again, anyway
sudo launchctl stop homebrew.mxcl.dnsmasq
sudo launchctl start homebrew.mxcl.dnsmasq

Make OSX resolve all .dev domains using our local DNS server (details)

sudo mkdir -p /etc/resolver
echo nameserver 127.0.0.1 >> /tmp/deans
sudo mv /tmp/devns /etc/resolver/dev

References/acknowledgements

This library uses

• the docker remote API
• NodeJS bindings by mafintosh
• Tool to get DOCKER_HOST also by mafintosh