how to configure ingress to direct traffic to an https backend using https - kubernetes

Question

I have a backend using https.
I want to separate load on that back-end based on URL/path.
I decided to use ingress to do this url/path based logic in order to move traffic to different back-ends ( same back-ends , just duplicated to different NodePorts )
my question is how I can configure the ingress to receive https requests and to forward those https requests to the https back-end?
thanks
edit:
I added the yaml file:
spec:
rules:
- http:
paths:
- backend:
serviceName: service
servicePort: 9443
path: /carbon
- backend:
serviceName: service2
servicePort: 9443
path: /oauth
for some reason I can;t change the rule form http to https

Answer 1

Attention: This answer applies to the ingress-nginx solution provided by the kubernetes organisation on github (https://github.com/kubernetes/ingress-nginx)
If you want to use load balancing mechanisms in k8s you should use services instead and start multiple instances behind that service that way k8s will do the load balancing. If you want to use different versions of your backend (e.g. prod and test) your way of separating them is fine
if your service is only reachable via https you need to add the following annotation to your ingress yaml: (documentation)
nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
To secure ingress itself take a look at this: https://kubernetes.io/docs/concepts/services-networking/ingress/#tls
But if you want that the backend services decrypt the TLS communication use the following annotation instead: (documentation)
nginx.ingress.kubernetes.io/ssl-passthrough: "true"
Edit:
The Ingress YAML should look like this if you want to reach the backend via TLS:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ingress-name
namespace: namespace-name
annotations:
nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
rules:
- http:
paths:
- backend:
serviceName: service
servicePort: 9443
path: /carbon
- backend:
serviceName: service2
servicePort: 9443
path: /oauth
The Ingress YAML should look like this if you want to reach the backend via TLS with TLS decryption in the ingress controller:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ingress-name
namespace: namespace-name
annotations:
nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
tls:
- hosts:
- app.myorg.com
secretName: tls-secret
rules:
- http:
paths:
- backend:
serviceName: service
servicePort: 9443
path: /carbon
- backend:
serviceName: service2
servicePort: 9443
path: /oauth
It's important to note that tls-secret is the name of a SecretConfig with a valid Certificate issued for the host (app.myorg.com)
The Ingress YAML should look like this if you want to reach the backend via TLS with TLS decryption in the backend:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ingress-name
namespace: namespace-name
annotations:
nginx.ingress.kubernetes.io/ssl-passthrough: "true"
spec:
rules:
- http:
paths:
- backend:
serviceName: service
servicePort: 9443
path: /carbon
- backend:
serviceName: service2
servicePort: 9443
path: /oauth
I never tested the last version myself so i don't know if that actually works but I'd strongly advise reading this passage for that variant.

Answer 2

If you are using the NGINX Ingress controller (https://docs.nginx.com/nginx-ingress-controller/), the nginx.ingress.kubernetes.io/backend-protocol: "HTTPS" does not work. However, the nginx.org/ssl-services will let you pick the services that require TLS on the backend. The name is confusing, so it took me a while to realize the real purpose of it.
This does not work with the standard Kubernetes Ingress controller that uses NGINX under the hood; it only works with the NGINX-sourced controller.
Advanced annotation docs: https://docs.nginx.com/nginx-ingress-controller/configuration/ingress-resources/advanced-configuration-with-annotations/
In this example, NGINX will connect to the ssl-svc using TLS; it ignores any self-signed certificates. Example (https://github.com/nginxinc/kubernetes-ingress/tree/v1.12.0/examples/ssl-services):
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: cafe-ingress
annotations:
nginx.org/ssl-services: "ssl-svc"
spec:
rules:
- host: cafe.example.com
http:
paths:
- path: /tea
backend:
serviceName: tea-svc
servicePort: 80
- path: /coffee
backend:
serviceName: coffee-svc
servicePort: 80
- path: /ssl
backend:
serviceName: ssl-svc
servicePort: 443