Create a local cluster with Vagrant/CoreOS/Docker

Question

I'm trying to create a local environment for testing purpose composed of:

• a Vagrant CoreOS Cluster (3 nodes)
• a Docker container launched with an Nginx image loaded, launched on one node

I've successfully installed Vagrant and CoreOS. Etcd is up and running and I've played a lot with Fleet. I've also launched a Nginx container throw Fleet services. What I can't really figure out is:

• How can I route traffic on a specific container? I want that pointing my local browser to a local address (i.e. example.dev), the cluster answers with the right Nginx container (placed somewhere on the cluster).
• Is a proxy an appropriate solution? If not - is there something created for this purpose?

Thanks in advance and feel free to ask more details I may have forgotten!

Answer 1

The simple answer is just to edit your local hosts file, e.g. /etc/hosts on Linux or OS X, or C:\Windows\System32\drivers\etc\hosts on a typical Windows box.

If you want something that's more production-level than a quick fix for development, then what you need is a reverse proxy like nginx or haproxy, and have it automatically configured by the availability of backend nginx containers.

• each backend nginx container will need a 'sidekick' service to announce its availability to etcd
• then run confd to listen for etcd changes and update the configuration of the reverse proxy

This allows you to route a single port on the reverse proxy to any number of backend nginx services which need only listen on the private network.

I've written a more detailed illustration of this approach here.