Kubernetes Ingress: 7 Common Mistakes (and How to Avoid Them)

You've finally tamed Kubernetes Ingress — or so you think. Then weird routing errors, downtime, and mysterious 404s show up. Welcome to the club! 🎩

Let's save you some headaches. Here are 7 common Kubernetes Ingress mistakes, how they happen, and how to dodge them like a pro.

Quick Mistakes Checklist

Forgetting to Deploy an Ingress Controller

Symptom:

• Your Ingress resource is happily created... but no traffic ever reaches your app.

Why:

• Ingress needs a controller (like NGINX, Traefik, HAProxy).
• Kubernetes doesn't come with one by default.

How to Avoid:

• Install an Ingress Controller manually.
• Use something like:

1kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/main/deploy/static/provider/cloud/deploy.yaml

• Make sure it’s running and ready.

Pro Tip: If you see no matches for kind "Ingress", check your controller is alive.

Mixing Up Path vs Host Routing

Symptom:

• Traffic goes to the wrong backend.

Why:

• Forgetting that Ingress matches hosts first, then paths.

How to Avoid:

• Know the flow:

  1. Match host
  2. Then match path

• Example:

1- host: api.example.com
2  path: /
3- host: shop.example.com
4  path: /cart

Wrong: expecting /cart at api.example.com to route!

Right: set both host and path carefully.

Ignoring PathType

Symptom:

• Ingress works on some URLs but not others.

Why:

• Kubernetes requires pathType (since v1.18+).
• Defaults aren't what you expect.

How to Avoid:

Set your pathType!

1pathType: Prefix

Options:

• Prefix: Match any path starting with /foo
• Exact: Match exactly /foo
• ImplementationSpecific: (aka Controller decides — spooky)

Prefer Prefix unless you love surprises.

TLS Configuration Failures

Symptom:

• HTTPS connections fail. Browser shows "Connection not secure."

Why:

• Missing or invalid TLS secret.
• Wrong secret name.
• Controller not picking it up.

How to Avoid:

• Create your TLS secret:

1kubectl create secret tls my-tls-secret --cert=cert.pem --key=key.pem

• Reference it properly:

1spec:
2  tls:
3  - hosts:
4    - myapp.example.com
5    secretName: my-tls-secret

Checklist:

• Secret in the same namespace as the Ingress!
• Correct secret name.
• Controller supports TLS (NGINX, Traefik do).

Wrong or Missing IngressClass

Symptom:

• Ingress resource is ignored.

Why:

• Kubernetes 1.18+ uses spec.ingressClassName to match Controllers.
• If it doesn’t match, your Ingress won’t be picked up.

How to Avoid:

• Set it explicitly:

1spec:
2  ingressClassName: nginx

• Match whatever your Controller reports as IngressClass.

You can check installed classes:

1kubectl get ingressclass

Incorrect Backend Service Configuration

Symptom:

• Ingress routes traffic but you get 502/503 errors.

Why:

• Ingress is fine, but the Service points to nowhere.
• Wrong service name or port.

How to Avoid:

• Double-check backend services.

Example:

1backend:
2  service:
3    name: api-service
4    port:
5      number: 80

• Service must exist.
• Service must target Pods correctly (selectors right).

Debug Tip:

• Check your service endpoints:

1kubectl get endpoints

• If it's empty, your Pods don't match.

Overlooking Health Checks

Symptom:

• Random 504 Gateway Timeouts.

Why:

• Ingress Controllers perform health checks on Services.
• If your app doesn’t respond fast enough, it’s marked unhealthy.

How to Avoid:

• Make sure your app is ready!
• Expose health endpoints (/health, /readyz)
• Tune Controller's timeout settings via annotations:

Example for NGINX:

1metadata:
2  annotations:
3    nginx.ingress.kubernetes.io/proxy-read-timeout: "30"
4    nginx.ingress.kubernetes.io/proxy-send-timeout: "30"

Bonus: Pro Moves

• Version mismatch: Check your Ingress resource version (networking.k8s.io/v1)!
• Custom error pages: Many Controllers allow custom 404/503 pages. Nice for UX.
• Rate limiting: Protect your services from abuse with Controller-specific options.

Wrapping Up

Kubernetes Ingress is powerful but a little... temperamental. 😉

Avoid these 7 common mistakes and your cluster will reward you with:

• Faster deployments
• Cleaner networking
• Happier users (and fewer 2 a.m. calls)

You got this!