Advanced Kubernetes: Ingress Controllers and Service Mesh

Uncover the power of Kubernetes networking with a deep dive into Kubernetes Ingress controller, Service Mesh technologies.

Himanshu Pant

Published: December 18, 2023

Key takeaways

Ingress Controllers Simplify Traffic Management: Kubernetes Ingress controllers like NGINX deals with routing, SSL termination and load balancing of the outside traffic to make it easier to expose the deployed services in a cluster.
Service Meshes Enhance Communication: Services mesh tool like Istio can be seen as an extra layer of service communication which brings service communication features such as load balancing and security, as well as observability which is critical in large and complex applications.
Network Policies Secure Pod Communication: The usage of Kubernetes Network Policies is beneficial since it enables the determination of networks that pods can accept traffic from and to which networks they can send traffic to, thus improving security and efficient management of traffic

Introduction

Kubernetes has become the de facto standard for container orchestration, enabling developers to deploy and manage containerized applications at scale. While Kubernetes simplifies many aspects of application deployment, managing and configuring networking in a Kubernetes cluster can be a complex task, especially as applications become more distributed and interconnected. In this blog, we will delve into advanced Kubernetes networking concepts, focusing on Kubernetes Ingress controller, Service Mesh technologies, and network policies.

Understanding Ingress Controllers

In Kubernetes, an Ingress is an API object that manages external access to services within a cluster. Kubernetes Ingress controllers are responsible for implementing the rules set by the Ingress resource, allowing external traffic to reach the appropriate services. They act as the entry point for external requests, handling routing, SSL termination, and load balancing.

Nginx Ingress Controller Example

Let’s take a look at an example using the Nginx Ingress Controller. First, make sure you have the Kubernetes Ingress controller deployed in your cluster. You can use the following YAML manifest to deploy it:

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

apiVersion: networking.k8s.io/v1

kind: Ingress

metadata:

spec:

rules:

- host: myapp.example.com

http:

paths:

- path: /

pathType: Prefix

backend:

service:

port:

number: 80

In this example, we define an Ingress resource that routes traffic from myapp.example.com to the myapp-service service on port 80. Adjust the host, path, and backend details according to your application’s needs.

Service Mesh Technologies

Service meshes provide a dedicated infrastructure layer for handling service-to-service communication, offering features like service discovery, load balancing, and security. Istio is one of the most popular service mesh solutions for kubernetes hpa best practices.

Istio Installation

To install Istio, you can use the following steps:

# Download and extract Istio
curl -L https://istio.io/download | ISTIO_VERSION=1.11.2 sh -
cd istio-1.11.2

# Install Istio to your cluster
istioctl install --set profile=default

# Deploy the Istio components
kubectl apply -f samples/addons

# Download and extract Istio

curl -L https://istio.io/download | ISTIO_VERSION=1.11.2 sh -

cd istio-1.11.2

# Install Istio to your cluster

istioctl install --set profile=default

# Deploy the Istio components

kubectl apply -f samples/addons

Istio Sidecar Injection

To leverage Istio’s features, you need to inject its sidecar proxy into your application pods. You can achieve this by adding the sidecar.istio.io/inject: "true" annotation to your pod template spec.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  template:
    metadata:
      annotations:
        sidecar.istio.io/inject: "true"
    spec:
      containers:
        - name: myapp-container
          image: myapp:latest
          ports:
            - containerPort: 80

apiVersion: apps/v1

kind: Deployment

metadata:

spec:

template:

metadata:

annotations:

sidecar.istio.io/inject: "true"

spec:

containers:

- name: myapp-container

image: myapp:latest

ports:

- containerPort: 80

This annotation ensures that Istio’s sidecar proxy is injected into the myapp deployment.

Network Policies

Kubernetes Network Policies allow you to control the communication between pods. They define rules that specify how groups of pods are allowed to communicate with each other.

Deny All Traffic Example

Here’s an example of a Network Policy that denies all traffic:

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-all
spec:
  podSelector: {}
  policyTypes:
  - Ingress
  - Egress

apiVersion: networking.k8s.io/v1

kind: NetworkPolicy

metadata:

spec:

podSelector: {}

policyTypes:

- Ingress

- Egress

This policy selects all pods (podSelector: {}) and specifies that both Ingress and Egress traffic are denied.

Conclusion

As your Kubernetes deployment grows in complexity, understanding advanced networking concepts becomes crucial. In this blog, we’ve explored Kubernetes Ingress controller for managing external access, Istio as a powerful service mesh solution, and Network Policies for controlling pod-to-pod communication. Implementing these technologies allows you to enhance security, improve observability, and streamline the management of your Kubernetes infrastructure. Feel free to experiment with the provided examples in your own kubernetes hpa best practices environment to deepen your understanding of these advanced networking concepts. For more details Contact Us.