I have three docker containers configured..
- ghost - a custom docker container which runs my ghost blog
- ghost-data - docker container which holds all the persistent data..
content/* config.js, newrelic.js
- jwilder/nginx-proxy - a docker container with nginx which sits in front of the ghost container
Using a single server I get how to link the nginx to the ghost container and get stuff served up through nginx.
However I want to start learning about coreos and migrate to a fleet of coreos servers. I know that in order to do this i need to write up service files for two of the containers (ghost, ghost-data) and make sure that ghost, and ghost-data are on the same host and nginx isn't.
As far as I understand, the whole point of fleet/clustering in coreos is uptime. containers will move from node to node as needed. The problem is, each of these nodes have their own IPs to the world. How do I get my DNS to know of these IPs and which IP has the nginx server on it?
The way I see it, something running like this..
- node1 - runs nginx-proxy, public ip of
- node2 - runs ghost, ghost-data, public ip of
- node3 - idle node, public ip of
DNS is pointing example.com to
What happens when coreos decide to move nginx-proxy to node3
How can i get the DNS to follow this? I'm sure in the service file there is a way to force nginx to stay on the same node, but that completely defeats the purpose doesn't it?