Ingress controllers (Nginx, Traefik) in Kubernetes - Mini Project: Build & Apply

Setting Up Ingress Controllers with Nginx and Traefik in Kubernetes

📖 Scenario: You are managing a Kubernetes cluster for a small company. You want to expose two simple web applications to the internet using Ingress controllers. You will set up both Nginx and Traefik ingress controllers and configure them to route traffic to the right apps.

🎯 Goal: Learn how to deploy Nginx and Traefik ingress controllers in Kubernetes and create ingress resources to route traffic to two web applications.

📋 What You'll Learn

Create Kubernetes namespaces for the apps

Deploy two simple web applications

Install Nginx ingress controller

Install Traefik ingress controller

Create ingress resources for both controllers

Test routing by accessing the apps via ingress

💡 Why This Matters

🌍 Real World

Ingress controllers are used in Kubernetes to manage external access to services inside the cluster. They help route internet traffic to the right app based on domain names or paths.

💼 Career

Knowing how to install and configure ingress controllers like Nginx and Traefik is essential for DevOps engineers and Kubernetes administrators to expose applications securely and efficiently.

1

Create namespaces and deploy web applications

Create two Kubernetes namespaces called app-nginx and app-traefik. Then deploy a simple nginx web server in app-nginx namespace and a simple httpd web server in app-traefik namespace. Use the image nginx:stable for nginx and httpd:latest for httpd. Name the deployments nginx-app and httpd-app respectively.

Kubernetes

# Create namespaces and deployments
# Your code here

Hint

Use kubectl create namespace to make namespaces and kubectl create deployment with --image and -n to deploy apps in namespaces.

2

Install Nginx ingress controller

Install the Nginx ingress controller in the ingress-nginx namespace using the official Kubernetes manifest from https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.9.1/deploy/static/provider/cloud/deploy.yaml. Create the namespace ingress-nginx before applying the manifest.

Kubernetes

kubectl create namespace ingress-nginx
# Apply the Nginx ingress controller manifest below
# Your code here

Hint

Use kubectl apply -f with the URL to install the Nginx ingress controller after creating its namespace.

3

Install Traefik ingress controller

Install the Traefik ingress controller in the ingress-traefik namespace. First create the namespace ingress-traefik. Then apply the official Traefik manifest from https://raw.githubusercontent.com/traefik/traefik/v2.10/docs/content/reference/dynamic-configuration/kubernetes-crd.yaml and https://raw.githubusercontent.com/traefik/traefik/v2.10/docs/content/reference/static-configuration/kubernetes-deployment.yaml in this order.

Kubernetes

kubectl create namespace ingress-traefik
# Apply Traefik CRD manifest
# Apply Traefik deployment manifest
# Your code here

Hint

Create the namespace first, then apply the CRD manifest, then the deployment manifest for Traefik.

4

Create ingress resources and test access

Create an ingress resource named nginx-ingress in the app-nginx namespace that routes host nginx.example.com to the nginx-app service on port 80. Also create an ingress resource named httpd-ingress in the app-traefik namespace that routes host httpd.example.com to the httpd-app service on port 80. Use the correct ingress class annotations: kubernetes.io/ingress.class: nginx for Nginx and kubernetes.io/ingress.class: traefik for Traefik. Finally, print Ingress setup complete to confirm.

Kubernetes

# Create nginx ingress resource YAML
# Create traefik ingress resource YAML
print("Ingress setup complete")

Hint

Use YAML manifests with correct ingress class annotations and apply them with kubectl apply -n <namespace> -f -. Then print the confirmation message.

Practice

1. What is the main role of an Ingress controller like Nginx or Traefik in Kubernetes?

easy

A. To monitor pod resource usage

B. To manage Kubernetes cluster nodes

C. To store container images

D. To route external traffic to internal Kubernetes services

Solution

1. Step 1: Understand Ingress controller purpose

   Ingress controllers manage how external users access services inside the Kubernetes cluster.

2. Step 2: Identify correct function

   Nginx and Traefik route incoming traffic to the right service based on rules.

3. Final Answer:

   To route external traffic to internal Kubernetes services -> Option D

4. Quick Check:

   Ingress controller = traffic router [OK]

Hint: Ingress controllers route external traffic inside Kubernetes [OK]

Common Mistakes:

• Confusing ingress controller with node management
• Thinking ingress stores images
• Mixing ingress with monitoring tools

2. Which annotation correctly specifies the use of the Nginx ingress controller in a Kubernetes Ingress resource?

easy

A. kubernetes.io/ingress.class: "nginx"

B. ingress.kubernetes.io/controller: "traefik"

C. kubernetes.io/controller: "nginx"

D. ingress.class: "nginx-controller"

Solution

1. Step 1: Recall correct annotation key for ingress class

   The standard annotation to specify ingress controller is kubernetes.io/ingress.class.

2. Step 2: Match correct value for Nginx

   The value for Nginx ingress controller is "nginx".

3. Final Answer:

   kubernetes.io/ingress.class: "nginx" -> Option A

4. Quick Check:

   Annotation key = kubernetes.io/ingress.class [OK]

Hint: Use kubernetes.io/ingress.class: "nginx" for Nginx [OK]

Common Mistakes:

• Using wrong annotation keys
• Mixing Traefik and Nginx values
• Omitting quotes around values

3. Given this Ingress YAML snippet using Traefik:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    kubernetes.io/ingress.class: "traefik"
spec:
  rules:
  - host: example.com
    http:
      paths:
      - path: /app
        pathType: Prefix
        backend:
          service:
            name: app-service
            port:
              number: 80

What happens when a user visits http://example.com/app/page?

medium

A. Traffic goes to default backend ignoring /app path

B. Traffic is blocked because pathType is incorrect

C. Traffic is routed to the app-service on port 80

D. Ingress controller returns 404 error

Solution

1. Step 1: Analyze ingress rule for host and path

   The rule matches host example.com and path prefix /app, so /app/page matches.

2. Step 2: Check backend service and port

   Requests matching the path are sent to app-service on port 80.

3. Final Answer:

   Traffic is routed to the app-service on port 80 -> Option C

4. Quick Check:

   Path prefix match routes traffic correctly [OK]

Hint: Path prefix routes all subpaths to backend service [OK]

Common Mistakes:

• Assuming pathType Prefix is invalid
• Ignoring host match requirement
• Thinking default backend handles matched paths

4. You deployed an Nginx ingress controller but your Ingress resource is not routing traffic. Which fix is most likely correct?

medium

A. Add annotation kubernetes.io/ingress.class: "nginx" to the Ingress resource

B. Change service port to 8080 in the Ingress backend

C. Remove all annotations from the Ingress resource

D. Restart the Kubernetes API server

Solution

1. Step 1: Identify cause of routing failure

   Ingress controller routes traffic only to Ingress resources with matching ingress.class annotation.

2. Step 2: Apply correct annotation for Nginx

   Adding kubernetes.io/ingress.class: "nginx" tells Nginx controller to manage this Ingress.

3. Final Answer:

   Add annotation kubernetes.io/ingress.class: "nginx" to the Ingress resource -> Option A

4. Quick Check:

   Ingress class annotation enables controller routing [OK]

Hint: Add ingress.class annotation matching controller [OK]

Common Mistakes:

• Changing service port without checking actual port
• Removing annotations disables routing
• Restarting API server does not fix ingress routing

5. You want to expose two services, webapp and api, on the same domain using Traefik ingress. The webapp should respond on / and api on /api. Which Ingress configuration correctly achieves this?

hard

A. Create two Ingresses with same host but no annotations

B. Use one Ingress with two paths: / to webapp and /api to api service, with annotation kubernetes.io/ingress.class: "traefik"

C. Use one Ingress with only /api path to api service, and no path for webapp

D. Create one Ingress with annotation kubernetes.io/ingress.class: "nginx" for Traefik

Solution

1. Step 1: Understand routing requirements

   Both services share the same domain; webapp on root path /, api on /api path.

2. Step 2: Configure single Ingress with multiple paths and correct annotation

   One Ingress resource with two paths and annotation kubernetes.io/ingress.class: "traefik" directs traffic properly.

3. Final Answer:

   Use one Ingress with two paths: / to webapp and /api to api service, with annotation kubernetes.io/ingress.class: "traefik" -> Option B

4. Quick Check:

   Multiple paths in one Ingress with correct class [OK]

Hint: One Ingress, multiple paths, correct ingress.class annotation [OK]

Common Mistakes:

• Using wrong ingress.class annotation for Traefik
• Creating multiple Ingresses without annotations
• Missing path for root service