NGINX Ingress Controller¶

The NGINX Ingress Controller is an Ingress Controller implementation for Kubernetes that uses NGINX as a reverse proxy and load balancer.^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md] It operates as a centralized entry point for external HTTP/HTTPS traffic accessing cluster services, managing domain name resolution and routing rules.^[400-devops-06-kubernetes-k8s-ingress-controller-docker-desktop-readme.md, 400-devops__06-Kubernetes__k8s-ingress-controller-docker-desktop__README.md]

Functionality¶

As an API object, the Ingress Controller manages external access to services, typically via HTTP, providing capabilities such as load balancing, SSL Termination, and Name-based Virtual Hosting.^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md] It accepts traffic from external sources and routes it to specific services within the cluster based on defined rules, such as hostnames (e.g., yudady.ml) or paths.^[400-devops-06-kubernetes-devops-helm-helm-jenkins-todo.md, 400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md]

A core feature is the ability to map a domain (host) to a specific backend service. For example, an Ingress resource can route traffic for myapp.od.com to a service named myapp-svc.^[400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md, 400-devops-06-kubernetes-devops-helm-helm-jenkins-todo.md]

Deployment and Installation¶

The controller can be deployed using various methods, including kubectl with official YAML manifests or via Helm.

Using Helm¶

For environments like Docker Desktop, the controller can be installed using the official Helm chart:

[Helm](<./helm.md>) upgrade --install ingress-nginx ingress-nginx \
  --repo https://kubernetes.github.io/ingress-nginx \
  --namespace ingress-nginx --create-namespace

Using Manifests (kubectl)¶

Alternatively, it can be applied directly using YAML manifests. A typical deployment creates a dedicated namespace (ingress-nginx), service accounts, ConfigMaps, RBAC roles, and a deployment for the controller itself.^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md, 400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md]

[kubectl](<./kubectl.md>) apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.3.1/deploy/static/provider/cloud/deploy.yaml

Service Exposure Types¶

The way the Ingress Controller exposes itself to the outside world depends on the Kubernetes environment configuration:

• LoadBalancer: In cloud environments or those supporting it, the controller service is often of type LoadBalancer, which provisions an external IP address.^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]
• NodePort: In bare-metal or self-managed clusters (like the setup shown in hdss7-11), the service typically defaults to or is configured as NodePort, exposing the controller via specific ports on the cluster nodes (e.g., port 30035 for HTTP).^[400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md]
• Port Forwarding: For local testing or development, users can forward a local port to the controller service.

  [kubectl port-forward](<./kubectl-port-forward.md>) --namespace=ingress-nginx service/ingress-nginx-controller 8080:80
  

  ^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]

Configuration and Networking¶

Ingress Resources¶

Routing logic is defined by creating Ingress resources that specify the ingressClassName (e.g., nginx), the host, and the backend service.^[400-devops-06-kubernetes-devops-helm-helm-jenkins-todo.md]

External Nginx Integration¶

In production setups, an external Nginx server (running on a node like hdss7-12) can be configured as a reverse proxy to the Ingress Controller.^[400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md]

This involves defining an upstream block pointing to the NodePorts of the Ingress Controller and configuring a server_name (e.g., *.od.com) to catch relevant traffic.^[400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md]

DNS¶

Domain Name System (DNS) records must be configured to resolve the application domains (e.g., myapp.od.com) to the IP address of the external Nginx proxy or the LoadBalancer/Node IP.^[400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md]

Related Concepts¶

• Kubernetes
• Helm
• Ingress
• [[Service]]
• [[Load Balancer]]

Sources¶

• 400-devops-06-kubernetes-k8s-ingress-controller-docker-desktop-readme.md
• 400-devops-06-kubernetes-devops-helm-helm-jenkins-todo.md
• 400-devops-06-kubernetes-k8s-learning-06ingress-readme.md
• 400-devops__06-Kubernetes__k8s-ingress-controller-docker-desktop__README.md
• 400-devops__06-Kubernetes__k8s-learning__linux__02-ingress__README.md