Ingress & TLS Security

Ingress is the primary security boundary for publicly exposed Kubernetes applications.

When users access your application from the internet, Ingress is the first component they hit.

This makes Ingress the ideal place to enforce HTTPS, apply TLS certificates, and control traffic securely.

This guide explains:

How TLS works with Kubernetes Ingress
Where HTTPS termination happens
How to use domains and certificates safely
Common mistakes to avoid when securing Ingress

Why TLS Matters for Ingress

Without TLS, traffic between users and your application is:

Unencrypted
Vulnerable to interception
Susceptible to man-in-the-middle attacks

TLS ensures:

Encrypted communication (HTTPS)
Server identity verification
Data integrity in transit

For any internet-facing Kubernetes service, TLS should be considered mandatory, not optional.

How Ingress and TLS Work Together

Ingress operates at Layer 7 (HTTP/HTTPS) and is designed to handle:

Host-based routing
Path-based routing
TLS termination

Typical Secure Traffic Flow

Internet
  ↓ HTTPS
Ingress Controller (TLS termination)
  ↓ HTTP
Service (ClusterIP)
  ↓
Pods

Key points:

TLS is terminated at the Ingress layer
Backend services remain private
Pods do not need public certificates

This design centralizes security and simplifies certificate management.

Domain Names and TLS Certificates

Internal vs Public Domains

Scope	Domain Type	TLS Required
Internal services	`.svc.cluster.local`	❌ No
Public services	Custom domain	✅ Yes

Kubernetes does not provide public domain names.

For public access:

You must purchase a domain from a domain provider
DNS records must point to:
- Ingress IP, or
- LoadBalancer IP

Example:

app.example.com → Ingress IP → Service → Pods

Configuring TLS with Ingress

TLS is configured inside the Ingress resource.

Basic TLS Ingress Example

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: web-ingress
spec:
  tls:
    - hosts:
        - app.example.com
      secretName: app-tls
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: web-service
                port:
                  number: 80