What is Kubernetes?

Kubernetes (often abbreviated as K8s) is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications.

Understanding Kubernetes

Kubernetes was originally developed by Google and is now maintained by the Cloud Native Computing Foundation (CNCF). It provides a framework for running distributed systems resiliently, handling scaling and failover for applications.

Key Features of Kubernetes

1. Container Orchestration

Automatically manages the deployment, scaling, and operation of application containers across clusters of hosts.

2. Self-Healing

Automatically replaces failed containers, kills containers that don't respond to health checks, and doesn't advertise them to clients until they're ready.

3. Horizontal Scaling

Can scale applications up or down manually or automatically based on CPU usage or custom metrics.

4. Load Balancing

Distributes network traffic to ensure deployment stability.

Basic Kubernetes Example

yamlCODE

# 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: my-app
        image: my-app:latest
        ports:
        - containerPort: 3000
---
apiVersion: v1
kind: Service
metadata:
  name: my-app-service
spec:
  selector:
    app: my-app
  ports:
  - port: 80
    targetPort: 3000
  type: LoadBalancer

Kubernetes vs Docker Swarm

| Feature | Kubernetes | Docker Swarm |

|---------|------------|--------------|

| Complexity | High | Low |

| Learning Curve | Steep | Gentle |

| Features | Rich | Basic |

| Community | Large | Smaller |

| Enterprise Support | Extensive | Limited |

Why Use Kubernetes?

Scalability: Automatically scale applications based on demand

Reliability: Self-healing and fault tolerance

Portability: Run anywhere - on-premises, public cloud, or hybrid

Ecosystem: Rich ecosystem of tools and integrations

Community: Large, active community and extensive documentation

Common Use Cases

Microservices Architecture

Cloud-Native Applications

High-Availability Systems

Big Data Applications

Machine Learning Workloads

Web Applications

Kubernetes Components

Control Plane Components

kube-apiserver: API server that exposes the Kubernetes API

etcd: Consistent and highly-available key-value store

kube-scheduler: Watches for newly created Pods and assigns them to nodes

kube-controller-manager: Runs controller processes

Node Components

kubelet: Agent that runs on each node

kube-proxy: Network proxy that maintains network rules

Container Runtime: Software responsible for running containers

Kubernetes Ecosystem

Helm: Package manager for Kubernetes

Istio: Service mesh for microservices

Prometheus: Monitoring and alerting

Grafana: Visualization and analytics

Kubernetes has become the de facto standard for container orchestration, powering applications at companies like Google, Netflix, Spotify, and many others.