Securely Hosting Multiple Applications on Kubernetes Using NGINX Ingress and Let's Encrypt TLS

Step-by-Step TLS Setup with Ingress Controller and Let's Encrypt

1. Problem Statement

In a typical Kubernetes setup, exposing multiple applications securely over the internet presents a variety of challenges. By default, each application often requires its own Load Balancer or NodePort, which leads to unnecessary cost, complexity, and management overhead—especially in cloud environments like Azure Kubernetes Service (AKS).

Additionally, enabling HTTPS (TLS/SSL) for secure communication traditionally requires manual generation, installation, and renewal of certificates, which is not scalable for a growing number of applications. For developers and DevOps engineers, managing these processes becomes tedious, error-prone, and inefficient.

Furthermore, managing DNS records across different cloud platforms and domain registrars adds another layer of complexity, especially when applications must be routed under different paths or subdomains from a single public endpoint.

This use case addresses these challenges by building a unified, scalable, and secure solution using:

• NGINX Ingress Controller for intelligent traffic routing within Kubernetes.

• Let’s Encrypt with cert-manager for automatic TLS certificate management.

• AWS Route 53 and custom domain configuration for simplified DNS management.

• A single public IP to host multiple apps under different paths (e.g., /nginx, /apache).

The goal is to reduce cost, simplify architecture, automate certificate renewal, and expose multiple containerized applications securely—without complex manual configurations—by leveraging open-source tools and cloud-native services.

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2. Why We Need This Use Case

In modern DevOps and cloud-native architecture, deploying multiple applications securely over the internet is a common requirement. With Kubernetes becoming the backbone of container orchestration, it is crucial to understand how to expose these services externally in a secure, scalable, and cost-effective manner.

This use case teaches us how to:

• Host multiple web applications on a single domain using Kubernetes.

• Implement NGINX Ingress Controller to manage traffic routing based on URL paths.

• Use Let’s Encrypt and cert-manager to automatically generate and renew TLS/SSL certificates, securing your applications with HTTPS.

• Integrate AWS Route 53 for DNS management and Azure Kubernetes Service (AKS) for hosting the cluster.

The setup mimics a real-world production environment and addresses key challenges such as secure routing, domain validation, certificate management, and application exposure—all through open-source tools and native cloud services.

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3. When We Need This Use Case

You’ll need this use case when:

• You are deploying multiple web applications on a Kubernetes cluster and want them accessible securely over the internet.

• You want to route traffic based on path or subdomain using a centralized Ingress Controller.

• You need a cost-effective way to manage HTTPS/TLS certificates without buying expensive third-party SSL certs.

• You’re building CI/CD pipelines that include infrastructure-as-code (IaC) and want to automate secure deployments.

• You want to learn or demonstrate real-world Kubernetes skills like DNS setup, ingress configuration, and TLS termination in a hands-on way.

• Your organization is migrating from monoliths to microservices and needs a robust traffic management and SSL solution.

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4. Challenge Questions