Ingress

consists of
Routing Rules
Ingress Controller

What

What is Ingress in Kubernetes?

Ingress in Kubernetes is an API object that manages external access to services within a cluster, typically HTTP and HTTPS. It provides a way to define rules for routing traffic from outside the cluster to services within the cluster.

What components are involved in Ingress?

• Ingress Resource: The configuration defining how requests should be routed.
• Ingress Controller: A controller that implements the rules defined in the Ingress resource, typically running as a Pod in the cluster.
• Ingress Class: A way to specify which Ingress controller should handle a particular Ingress resource, useful when multiple controllers are deployed.

Why

Why use Ingress?

Ingress is used to:

• Centralize Routing: Manage routing rules for multiple services in a single place.
• Support Multiple Hosts and Paths: Route traffic based on hostnames and URL paths.
• SSL/TLS Termination: Terminate SSL/TLS connections at the Ingress controller, offloading this task from backend services.
• Load Balancing: Distribute incoming traffic across multiple backend Pods for scalability and reliability.

Why choose Ingress over other networking options?

Ingress provides more advanced routing capabilities compared to basic Services and LoadBalancers, such as path-based routing, name-based virtual hosting, and SSL/TLS termination, making it more suitable for complex routing requirements.

How

How to create an Ingress resource?

You can create an Ingress resource by defining it in a YAML file and applying it to the cluster using kubectl.

Example Ingress YAML:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - host: example.com
    http:
      paths:
      - path: /app1
        pathType: Prefix
        backend:
          service:
            name: app1-service
            port:
              number: 80
      - path: /app2
        pathType: Prefix
        backend:
          service:
            name: app2-service
            port:
              number: 80
  tls:
  - hosts:
    - example.com
    secretName: example-tls

This example defines an Ingress that routes traffic based on the path and uses TLS for secure communication.

How to deploy an Ingress Controller?

Ingress resources require an Ingress controller to function. Popular controllers include NGINX, Traefik, and HAProxy.

Example command to deploy NGINX Ingress Controller:

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/main/deploy/static/provider/cloud/deploy.yaml

This command deploys the NGINX Ingress controller to your cluster.

How to verify Ingress is working?

• Check Ingress Resource: Use kubectl get ingress to list the Ingress resources and ensure they are correctly configured.
• Check Ingress Controller Logs: Use kubectl logs to view logs from the Ingress controller Pod for any errors or warnings.
• Test Access: Use a browser or HTTP client (e.g., curl) to send requests to the Ingress and verify the routing rules are applied correctly.

When

When should you use Ingress?

Use Ingress when you need to:

• Expose multiple services: Manage external access to multiple services using a single Ingress resource.
• Implement complex routing rules: Use path-based or host-based routing to direct traffic to different services.
• Terminate SSL/TLS: Handle SSL/TLS termination at the Ingress controller.
• Offload load balancing: Distribute incoming traffic across backend Pods.

When might Ingress not be suitable?

• Simple use cases: For simple use cases, such as exposing a single service, a LoadBalancer or NodePort might be sufficient.
• Non-HTTP/S traffic: Ingress is primarily designed for HTTP/S traffic. For other protocols, consider using other types of services or custom solutions.

Related Hashtags

#Kubernetes #Ingress #IngressController #Networking #LoadBalancing #SSLTLS #Routing #DevOps #ContainerOrchestration #ClusterManagement