🛠️ Kubernetes Intermediate: Configuration and Management

Kubernetes Intermediate: Configuration and Resource Management

Welcome to part 2 of our Kubernetes tutorial series! In this post, we’ll explore more advanced concepts and learn how to properly configure and manage your applications in Kubernetes.

What We’ll Cover

Configuration Management with ConfigMaps
Managing Secrets
Resource Management
Advanced Deployment Strategies

Prerequisites

Completed our Kubernetes Basics tutorial
Running Kind cluster
Basic YAML understanding

ConfigMaps: Managing Application Configuration

ConfigMaps allow you to decouple configuration from your container images.

# config-map.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  app.properties: |
    environment=development
    log.level=debug
  database.properties: |
    db.url=localhost:5432
    db.name=myapp

Using ConfigMaps in Pods

apiVersion: v1
kind: Pod
metadata:
  name: config-test-pod
spec:
  containers:
  - name: test-container
    image: busybox
    volumeMounts:
    - name: config-volume
      mountPath: /etc/config
  volumes:
  - name: config-volume
    configMap:
      name: app-config

Secrets: Managing Sensitive Data

# Create a secret
apiVersion: v1
kind: Secret
metadata:
  name: app-secrets
type: Opaque
data:
  db-password: BASE64_ENCODED_PASSWORD
  api-key: BASE64_ENCODED_API_KEY

Using Secrets as Environment Variables

apiVersion: v1
kind: Pod
metadata:
  name: secret-test-pod
spec:
  containers:
  - name: test-container
    image: myapp
    env:
    - name: DB_PASSWORD
      valueFrom:
        secretKeyRef:
          name: app-secrets
          key: db-password

Resource Management

Setting Resource Requests and Limits

apiVersion: v1
kind: Pod
metadata:
  name: resource-demo
spec:
  containers:
  - name: resource-demo-container
    image: nginx
    resources:
      requests:
        memory: "64Mi"
        cpu: "250m"
      limits:
        memory: "128Mi"
        cpu: "500m"

Resource Quotas

apiVersion: v1
kind: ResourceQuota
metadata:
  name: compute-quota
spec:
  hard:
    requests.cpu: "1"
    requests.memory: 1Gi
    limits.cpu: "2"
    limits.memory: 2Gi

Advanced Deployment Strategies

Rolling Updates

apiVersion: apps/v1
kind: Deployment
metadata:
  name: rolling-demo
spec:
  replicas: 3
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  # ... rest of deployment spec

Blue-Green Deployments

# service.yaml
apiVersion: v1
kind: Service
metadata:
  name: my-app
spec:
  selector:
    app: my-app
    version: blue  # Switch between blue and green
  ports:
  - port: 80

Hands-on Exercise: Complete Application Setup

Let’s create a complete application setup with:

ConfigMap for application settings
Secret for sensitive data
Deployment with resource limits
Service for exposure

# Complete example in the repository

What’s Next?

In the next post, we’ll explore:

StatefulSets and persistent storage
Networking and Service Mesh
Monitoring and logging
Horizontal Pod Autoscaling

Additional Resources

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