kubernetes - route ingress traffic to specific pod for some paths - kubernetes

Question

I have multiple pods, that scale up and down automatically.
I am using an ingress as entry point. I need to route external traffic to a specific pod base on some conditions (lets say path). At the point the request is made I am sure the specific pod is up.
For example lets say I have domain someTest.com, that normally routes traffic to pod 1, 2 and 3 (lets say I identify them by internal ips - 192.168.1.10, 192.168.1.11 and 192.168.1.13).
When I call someTest.com/specialRequest/12, I need to route the traffic to 192.168.1.12, when I call someTest.com/specialRequest/13, I want to route traffic to 192.168.1.13. For normal cases (someTest.com/normalRequest) I just want to do the lb do his epic job normally.
If pods scale up and 192.168.1.14 appears, I need to be able to call someTest.com/specialRequest/14 and be routed to the mentioned pod.
Is there anyway I can achieve this?

Answer 1

Yes, you can easily achieve this using Kubernetes Ingress. Here is a sample code that might help:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: app-ingress
spec:
rules:
- host: YourHostName.com
http:
paths:
- path: /
backend:
serviceName: Service1
servicePort: 8000
- path: /api
backend:
serviceName: Service2
servicePort: 8080
- path: /admin
backend:
serviceName: Service3
servicePort: 80
Please not that the ingress rules have serviceNames and not pod names, so you will have to create services for your pods. Here is an example for a service which exposes nginx as a service in Kubernetes:
apiVersion: v1
kind: Service
metadata:
name: nginx-service
labels:
io.kompose.service: nginx
spec:
ports:
- name: "80"
port: 80
targetPort: 80
selector:
io.kompose.service: nginx

Answer 2

I am not aware of built-in functionality to implement this (if this is what your really want). You can achieve this by building your own operator for Kubernetes. Your operator may provision a Pod+Ingress combo which will do exactly what you want - forward your traffic to a single pod, or you can provision 2 pods and 1 ingress to achive HA setup.
Depending on the Ingress you are using, it also may be possible to group multiple ingress resources under the same load balancer.
Here is a brief diagram of how this could look like.

Answer 3

would it be feasible to create another application
that can get the path and target the pod directly via
a pattern in the naming convention? for example
${podnamePrefix+param}.${service name}.${namespace}.svc.cluster.local