NEWS

July 21, 2025

by Tega Akuruli

• #k8s
• #kubernetes

Orchestrating Containers with Kubernetes 

Containerization with Docker changed how we build applications. Managing containers across multiple servers is where Kubernetes comes in. Kubernetes, also known as K8s, is a powerful platform that helps you automate the deployment, scaling, and management of applications in containers.  

This article explores Kubernetes concepts and how developers can use it for strong, scalable, and portable microservices architectures. 

Why Use Kubernetes?  

• Scalability: Automatically scale applications based on CPU, memory, or custom metrics.  
• Self-healing: Restarts crashed containers and reschedules failed pods.  
• Rolling updates: Allows zero-downtime deployments.  
• Portability: Works on local machines, in the cloud, or in hybrid environments. 

Core Components of Kubernetes

1. Pod 

• The smallest unit. Represents a single instance of a running container.
• Can run multiple closely linked containers.  

2. Node 

• A physical or virtual machine in the cluster. Can be a master or worker.  

3. Cluster 

• A group of nodes that run containerized applications.  

4. Deployment 

• Manages rolling updates, rollbacks, and scaling of pods.  

5. Service 

• Exposes pods to network traffic, either internal or external. Supports load balancing.  

6. Ingress 

• Controls external HTTP and HTTPS access to services, such as /api or /login routing.  

7. ConfigMap & Secret 

• Injects configuration and sensitive data without rebuilding container images. 

How Kubernetes Works (Simplified Flow) 

1. You define your app’s desired state in YAML (deployment.yaml).
2. Kubernetes compares the desired state to the current state.
3. It reconciles by creating, scaling, or replacing containers to match. 

Sample Deployment YAML  

apiVersion: apps/v1 
kind: Deployment 
metadata: 
  name: my-app 
spec: 
  replicas: 3   
  selector: 
    matchLabels: 
      app: my-app 
  template: 
    metadata: 
      labels:   
        app: my-app 
    spec: 
      containers:   
        – name: app-container 
          image: my-app:v1 
          ports: 
            – containerPort: 80  

Kubernetes in Practice  

1. Autoscaling 

• Use Horizontal Pod Autoscaler (HPA) to scale pods based on CPU or memory.  

kubectl autoscale deployment my-app –cpu-percent=50 –min=2 –max=10 

2. Rollouts and Rollbacks  

# Apply new version 
kubectl apply -f deployment.yaml 

# Check rollout status 
kubectl rollout status deployment/my-app 
 
# Rollback if broken 
kubectl rollout undo deployment/my-app 

3. Observability 

• Tools like Prometheus, Grafana, and Kubernetes Dashboard provide real-time cluster monitoring. 

4. Helm Charts 

• Package K8s applications with Helm, a package manager for Kubernetes.  

helm install myapp ./myapp-chart  

Where to Run Kubernetes  

• Minikube: Run locally for development.  
• EKS/GKE/AKS: Fully managed Kubernetes on AWS, Google Cloud, and Azure.  
• K3s: A lightweight version for edge or IoT deployments. 

Kubernetes helps teams move from manual container management to automated, scalable orchestration. Once you understand its concepts, deploying strong, cloud-native applications becomes easy.