Managing Ingress and Egress Traffic in AKS - Tutorial

Prerequisites

Before you begin, ensure you have the following prerequisites:

• An Azure subscription
• An AKS cluster deployed
• Azure CLI installed

Step 1: Set Up an Ingress Controller

To manage incoming traffic to your AKS cluster, you need to set up an Ingress Controller. Follow these steps:

1. Create an Ingress Controller using the NGINX Ingress Controller:

2. Create an Ingress resource to define the routing rules for incoming traffic:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /app1
            pathType: Prefix
            backend:
              service:
                name: app1-service
                port:
                  number: 80
          - path: /app2
            pathType: Prefix
            backend:
              service:
                name: app2-service
                port:
                  number: 80

Step 2: Configure Network Policies

To manage egress traffic and control communication between pods in your AKS cluster, you can use Network Policies. Follow these steps:

1. Enable the Azure Network Policy Addon for your AKS cluster:

2. Create a Network Policy to define the allowed ingress and egress traffic:

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: my-network-policy
spec:
  podSelector:
    matchLabels:
      app: my-app
  policyTypes:
    - Ingress
    - Egress
  ingress:
    - from:
        - podSelector:
            matchLabels:
              app: allowed-app
          namespaceSelector:
            matchLabels:
              namespace: allowed-namespace
  egress:
    - to:
        - podSelector:
            matchLabels:
              app: external-app

Step 3: Use Azure Firewall for Advanced Traffic Management

If you require more advanced traffic management and security, you can use Azure Firewall. Follow these steps:

1. Create an Azure Firewall resource in your Azure subscription.
2. Configure the Azure Firewall rules to allow or deny traffic based on your requirements.
3. Configure your AKS cluster to route traffic through the Azure Firewall.

Common Mistakes to Avoid

• Not configuring the correct routing rules in the Ingress resource, resulting in incorrect traffic routing.
• Forgetting to enable the Azure Network Policy Addon before creating Network Policies.
• Misconfiguring Azure Firewall rules, leading to unintended blocking or allowing of traffic.

Frequently Asked Questions

1. Can I use multiple Ingress Controllers in my AKS cluster?

   Yes, you can use multiple Ingress Controllers in your AKS cluster to manage traffic for different applications or routing scenarios.

2. Can I use Network Policies to control egress traffic to external services?

   Yes, you can use Network Policies to control egress traffic from your AKS cluster to external services by specifying egress rules in the Network Policy manifest.

3. Can I apply Network Policies to specific namespaces only?

   Yes, you can apply Network Policies to specific namespaces by specifying the namespaceSelector in the Network Policy manifest.

4. Does Azure Firewall provide DDoS protection?

   Yes, Azure Firewall provides built-in DDoS protection to help safeguard your AKS cluster from DDoS attacks.

5. Can I use Azure Firewall to filter traffic based on IP addresses or port numbers?

   Yes, Azure Firewall allows you to define rules based on source or destination IP addresses, port numbers, protocols, and other criteria.

Summary

Managing ingress and egress traffic in Azure Kubernetes Service (AKS) is essential for controlling the flow of network traffic to and from your applications. By setting up an Ingress Controller, configuring Network Policies, and utilizing Azure Firewall, you can effectively manage and secure your application's network traffic. Avoid common mistakes such as misconfiguring routing rules, forgetting to enable the Azure Network Policy Addon, or misconfiguring Azure Firewall rules. With proper traffic management, you can enhance the performance, security, and reliability of your applications in AKS.