Accessing an External Resource from Kubernetes

Sometimes not all of your services are running on a Kubernetes cluster. Maybe your database is sitting on a server external to your cluster, since you do not want it to be ephemeral. In that case how does a service within Kubernetes connect to it? You just need to create a couple of yaml files and apply them. Now this may not be the optimal or most restrictive approach, since I do not define selectors; but it should be enough to get you started and getting your app to communicate to your external database.

Create a yaml file and add the following(replace the appropriate info, like the DNS, port, etc)

kind: Service
apiVersion: v1
metadata:
  name: external-db
  namespace: default
spec:
  type: ExternalName
  externalName: my.database.com
  ports:
 		- port: 1521
  protocol: TCP
  targetPort: 1521

> kubectl apply -f my-service.yaml

Create another yaml file and add the following

 kind: Endpoints
 apiVersion: v1
  metadata:
    name: external-db
    namespace: default

> kubectl apply -f my-endpoint.yaml

Now your application should be able to access the external database.