Ingress

An ingress controller consists of:

• Ingress Controller: A deployment that implements the Ingress rules (e.g., NGINX, HAProxy)
  • Managed via kubectl edit deployment <ingress-controller-name>
• Ingress Resource: The configuration object that defines routing rules
  • Managed via kubectl edit ingress <ingress-name>
• IngressClass: Specifies which controller should implement the Ingress resource
  • Links Ingress resources to their respective controllers
• Controller Pods: The actual running instances of the controller (e.g., NGINX pods)
• ConfigMap: Stores controller configuration settings
• Service: Exposes the Ingress controller to external traffic
• ServiceAccount: Provides necessary permissions for the controller to access K8s API

Multiple Ingresses (resources/configs)

An Ingress deployment can watch multiple Ingress resources for the path matchings.

$ k get ingress # Ingress resource object (rules)
$ k get ingressclass # The Ingress controller type

kubectl create ingress my-ingress \
  --class=nginx \ # If not specified, uses the default one, may not work!!
  --rule="wear.my-online-store.com/wear*=wear-service:80"

# Ingress is a deployment itself with it's own pods running in a namespace
$ k get deployments.apps -A | grep ingress
ingress-nginx   ingress-nginx-controller   1/1     1            1           16m

-> Ingress Deployment has the default backend service defined.

ingress.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata: 
	name: ingress-wear-watch
   annotations:
     nginx.ingress.kubernetes.io/rewrite-target: / #rewrites to / from /wear
     nginx.ingress.kubernetes.io/ssl-redirect: false #rewrites to / from /wear
spec:
	ingressClassName: nginx # If not specified, uses the default one, may not work!!
	rules:
	- host: incoming-host.com # If you omit, it is *
	   http: 
		paths: 
		- path: /wear
		  backend: 
			service:
				name: wear-service
				port:
					number: 80
		- path: ...

Ingress defines path forwardings to services, should be in the services namespace Service is the hostname with round-robin to pods. Service can use kube expose to be created with selectors An external service can be in another namespace Ingress Controller is the