Port to Crystal

[ysbaddaden]

What about having Dockerdev written in Crystal instead of Go?

The Docker shard only implements the authentication (and a couple example bindings), so I had to generate the bindings needed for talking with the Docker server. Apart from that it's basically the same, but written in Crystal instead of Go.

Bonuses:

• the shared network is now customizable and will be created automatically (closes Have dockerdev create the shared network #2)
• uses alpine images and the end image is down to 79MB instead of 171MB.

Warning: I only tested it quickly. It properly associates compose containers to the shared network and sets the DNS alias. I didn't test if everything is working correctly wih a more complex setup (e.g. NCD).

[ysbaddaden]

I had an issue locally where web.verboice.lvh.me didn't resolve to the container's IP from Surveda (despite the aliases being properly set), while another container didn't have issue reaching web.nuntium.lvh.me.

I rebuilt the image using the debian image of nginx-proxy, instead of alpine, and now it's working after restarting surveda's container. That's weird.