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Configure DNS

For Deis clusters, DNS records must be created. The Deis cluster runs multiple routers infront of the Deis controller and apps you deploy, so a load balancer is recommended.

You can find the IP addresses of your Kubernetes cluster nodes by running kubectl get nodes.

Necessary DNS records

Deis requires a wildcard DNS record. Assuming myapps.com is the top-level domain apps will live under:

  • *.myapps.com should have "A" record entries for each of the load balancer's IP addresses

Apps can then be accessed by browsers at appname.myapps.com, and the controller will be available to the Deis client at deis.myapps.com.

AWS recommends against creating "A" record entries; instead, create a wildcard "CNAME" record entry for the load balancer's DNS name, or use Amazon Route 53.

These records are necessary for all deployments of Deis other than Vagrant clusters.

DNS without a Load Balancer

On some platforms (Vagrant, for instance), a load balancer is not an easy or practical thing to provision. In these cases, one can directly identify the public IP of a Kubernetes node that is hosting a router pod and use that information to configure DNS or the local /etc/hosts file.

You can find the IP address of a node using kubectl:

$ kubectl get pods --namespace=deis | grep deis-router
deis-router-ih25q           1/1       Running   0          2h

Using the pod name determined through the above, one can use kubectl to determine what node the pod is running on:

$ kubectl describe pod deis-router-ih25q --namespace=deis

The Node field of the response should provide an IP:

Node:				10.245.1.3/

If the IP is public, this can be used to configure DNS or the local /etc/hosts file.

An easy way to configure wildcard DNS is to use [xip.io][] to reference the IP of the node running your router. For example:

$ deis register http://deis.10.245.1.3.xip.io

Note that xip does not seem to work for AWS ELBs - you will have to use an actual DNS record.

Alternatively, in your /etc/hosts file, add an entry like this:

10.245.1.3    example.com deis.example.com

This will get you started, though you may find that you have to manually maintain this file as you create and deploy more applications to the cluster.

Testing

To test that traffic reaches its intended destination, a request can be sent to the Deis controller like so:

curl http://deis.example.com/v2/

Since such requests require authentication, a response such as the following is an indicator of success:

{"detail":"Authentication credentials were not provided."}