Kubernetes Ingress - same path but with multiple ports possible?

Kubernetes Ingress - Same Path but with Multiple Ports Possible?

If you are new to Kubernetes and have been exploring its features, you might have come across the term "Ingress" in the context of routing external traffic to your applications. Ingress is a powerful Kubernetes resource that allows you to control the inbound traffic to your cluster. It acts as an entry point for external requests and provides routing rules to direct traffic to the appropriate services within your cluster. But can you have the same path but with multiple ports in Kubernetes Ingress? Let's find out!

Understanding Kubernetes Ingress

Before diving into the details, let's quickly understand what Kubernetes Ingress is. Ingress is an API object that manages external access to the services in a cluster. It provides a way to configure the routing of HTTP and HTTPS traffic from outside the cluster to services within the cluster. Ingress can be seen as a reverse proxy that sits between external clients and your services, enabling you to define rules for traffic routing, load balancing, SSL termination, and more.

Path-Based Routing in Kubernetes Ingress

Path-based routing is a common use case in Kubernetes Ingress. It allows you to route traffic based on the URL path specified in the incoming request. For example, you can define rules to direct requests with the "/api" path to one service and requests with the "/app" path to another service. This provides a way to logically separate different parts of your application and direct traffic accordingly.

Multiple Ports in Kubernetes Ingress

By default, Kubernetes Ingress supports routing traffic only on port 80 (HTTP) and port 443 (HTTPS). However, it is possible to configure Ingress to route traffic on multiple ports using annotations. Annotations are key-value pairs that can be added to Kubernetes resources to provide additional configuration or metadata. In the case of Ingress, you can use annotations to specify additional ports for routing traffic.

To configure multiple ports in Kubernetes Ingress, you need to add the appropriate annotations to your Ingress resource. Here's an example of how you can define an Ingress resource with multiple ports:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
    nginx.ingress.kubernetes.io/secure-backends: "true"
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/proxy-send-timeout: "600"
    nginx.ingress.kubernetes.io/proxy-read-timeout: "600"
    nginx.ingress.kubernetes.io/affinity: "cookie"
    nginx.ingress.kubernetes.io/session-cookie-name: "route"
    nginx.ingress.kubernetes.io/session-cookie-expires: "172800"
    nginx.ingress.kubernetes.io/session-cookie-max-age: "172800"
    nginx.ingress.kubernetes.io/session-cookie-secure: "true"
spec:
  rules:
    - http:
        paths:
          - path: /api
            pathType: Prefix
            backend:
              service:
                name: api-service
                port:
                  number: 8080
          - path: /app
            pathType: Prefix
            backend:
              service:
                name: app-service
                port:
                  number: 8081
  

In the above example, we have defined an Ingress resource with two paths ("/api" and "/app") and their corresponding backend services. The first path ("/api") is routed to the "api-service" on port 8080, while the second path ("/app") is routed to the "app-service" on port 8081. This way, you can have the same path but with multiple ports in Kubernetes Ingress.

Kubernetes Ingress provides a flexible and powerful way to route external traffic to your services. While it supports routing traffic on default ports 80 and 443, you can configure Ingress to route traffic on multiple ports using annotations. This allows you to have the same path but with different ports for different services within your cluster. By leveraging path-based routing and multiple ports, you can effectively manage and control inbound traffic to your applications in Kubernetes.

References