Azure AKS Loadbalancer serving multiple pods using service on same IP

Question

I currently have a load balancer per pod. In my instance 2 pods with the following YAML definitions.

apiVersion: v1
kind: Service
metadata:
  name: service1
spec:
  ports:
  - name: https-service1
    port: 6379
    targetPort: 6379
  selector:
       app: service1-consoleapp
  type: LoadBalancer

apiVersion: v1
kind: Service
metadata:
  name: service2
spec:
  ports:
  - name: https-service2
    port: 443
    targetPort: 443
  selector:
       app: service2-consoleapp
  type: LoadBalancer

When I apply the above 2 yaml files I will get 2 external ip's that I then use to configure my A records in my dns subdomains.

service1.company.com => external ip 1 for service1-consoleapp

service2.company.com => external ip 2 for service2-consoleapp

Is there a way to combine the YAML file into one, so that I can only use one IP address instead of 2 ?

Also , it looks like in ingress you can do it but not sure how I deal with the "host" requirement.

Can someone please explain how the routing will work as I'm not sure what values should be in the path property ?

Will I still get 2 external ip's on this that I can use to populate the dns subdomains ?

 spec:
  rules:
  - host: service1.company.com
    http:
      paths:
      - backend:
          serviceName: service1
          servicePort: 6379
        path: ??
  - host: service2.company.com
    http:
      paths:
      - backend:
          serviceName: service2
          servicePort: 433
        path: ??

The result I'm looking for is if I type

service1.company.com:6379 in my browser then I should hit the pod endpoint (service1-consoleapp) and if I type

service2.company.com:443 in my browser then I should hit the pod endpoint (service2-consoleapp).

where the service1.company.com and service2.company.com is on the same IP address.

thanks in advance.

Have you tried googling "kubernetes ingress"? This is the 1st result and it shows how to configure ingress routing https://kubernetes.io/docs/concepts/services-networking/ingress/ — CSharpRocks, Jul 10 '20 at 11:22
hi @CSharpRocks , that is the reference I'm using but do I don't understand the "path" reference and will I still get only one external IP that i use to populate my dns subdomains ? — user3385105, Jul 10 '20 at 11:27

score 2 · Answer 1 · answered Jul 10 '20 at 11:28

You better work with Microsoft documentation - Create an ingress controller in Azure Kubernetes Service (AKS).

From the docs:

An ingress controller is a piece of software that provides reverse proxy, configurable traffic routing, and TLS termination for Kubernetes services. Kubernetes ingress resources are used to configure the ingress rules and routes for individual Kubernetes services. Using an ingress controller and ingress rules, a single IP address can be used to route traffic to multiple services in a Kubernetes cluster.

Follow the documentation and set an ingress.

Later on, Follow Kubernetes documentation as @CSharpRocks offered in the comments.

From the docs:

If you create an Ingress resource without any hosts defined in the rules, then any web traffic to the IP address of your Ingress controller can be matched without a name based virtual host being required.

For example, the following Ingress resource will route traffic requested for first.bar.com to service1, second.foo.com to service2, and any traffic to the IP address without a hostname defined in request (that is, without a request header being presented) to service3.

Yaml example:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: name-virtual-host-ingress
spec:
  rules:
  - host: first.bar.com
    http:
      paths:
      - backend:
          serviceName: service1
          servicePort: 80
  - host: second.foo.com
    http:
      paths:
      - backend:
          serviceName: service2
          servicePort: 80
  - http:
      paths:
      - backend:
          serviceName: service3
          servicePort: 80

More about Path types.

Arghya Sadhu · Accepted Answer · 2020-07-10T11:36:20.620

1

The ingress resource that you have currently should work. Remove the path section completely. Also in your DNS you need to create subdomains service1.company.com, service2.company.com and a A record to point to IP of the loadbalancer.

This loadBalancer is the one which will route traffic form outside to ingress controller pods and ingress controller will forward the traffic to the backend pods according to rules defined in the ingress resource. The host rule works this way - if a HTTP request has a Host header service1.company.com ingress controller will send that request to service1 and if it has a Host header service2.company.com ingress controller will send that request to service2

When you deploy a ingress controller such as Nginx you need to create a LoadBalancer type service.So you will have only one loadBalancer which is for exposing ingress controller pods.

edited Jul 10 '20 at 11:36

answered Jul 10 '20 at 11:29

Arghya Sadhu

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Thanks @Arghya , if I understand correctly then this 1 YAML file should do the trick ? apiVersion: v1 kind: Service metadata: name: IntegratedServices spec: rules: - host: service1.company.com http: paths: - backend: serviceName: service1 servicePort: 6379 - host: service2.company.com http: paths: - backend: serviceName: service2 servicePort: 443 type: LoadBalancer Will this then work without an "app selector" section in the YAML – user3385105 Jul 10 '20 at 11:51
Hi @Arghya, just for clarity. Do I use one YAML that is a service where the app selector point to the ingress controller and a second YAML that defines the ingress controller ? or can I define just the one YAML file as in my previous comment ? – user3385105 Jul 10 '20 at 11:59
@user3385105 I think you should read the documentation and understand the logic behind the scenes.. otherwise even if it's working when you hit an exception you won't be able to fix it... – Amit Baranes Jul 10 '20 at 12:01

Azure AKS Loadbalancer serving multiple pods using service on same IP

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