Kubernetes Ingress to External Service?

Question

Say I have a service that isn't hosted on Kubernetes. I also have an ingress controller and cert-manager set up on my kubernetes cluster.

Because it's so much simpler and easy to use kubernetes ingress to control access to services, I wanted to have a kubernetes ingress that points to a non-kubernetes service.

For example, I have a service that's hosted at https://10.0.40.1:5678 (ssl required, but self signed certificate) and want to access at service.example.com.

Answer 1

You can do it by manual creation of Service and Endpoint objects for your external server.

Objects will looks like that:

apiVersion: v1 kind: Service metadata:   name: external-ip spec:   ports:   - name: app     port: 80     protocol: TCP     targetPort: 5678   clusterIP: None   type: ClusterIP --- apiVersion: v1 kind: Endpoints metadata:   name: external-ip subsets: - addresses:   - ip: 10.0.40.1   ports:   - name: app     port: 5678     protocol: TCP 

Then, you can create an Ingress object which will point to Service external-ip with port 80:

apiVersion: extensions/v1beta1 kind: Ingress metadata:   name: external-service spec:   rules:   - host: service.example.com     http:       paths:       - backend:           serviceName: external-ip           servicePort: 80         path: / 

Answer 2

If your external service has a dns entry configured on it, you can use kubernetes externalName service.

--- apiVersion: v1 kind: Service metadata:   name: my-service   namespace: prod spec:   type: ExternalName   externalName: myexternal.http.service.com --- apiVersion: extensions/v1beta1 kind: Ingress metadata:   name: externalNameservice   namespace: prod spec:   rules:   - host: service.example.com     http:       paths:       - backend:           serviceName: my-service           servicePort: 80         path: / 

In this way, kubernetes create cname record my-service pointing to myexternal.http.service.com