Ci-Cd

GitOps takes “Infrastructure as Code” literally: your Git repository becomes the single source of truth for what should be running. ArgoCD watches your repo and automatically synchronizes your cluster to match. No more kubectl apply from laptops, no more “what’s actually deployed?” mysteries. GitOps Principles Declarative: Describe the desired state, not the steps to get there Versioned: All changes go through Git (audit trail, rollback) Automated: Changes are applied automatically when Git changes Self-healing: Drift from desired state is automatically corrected Installing ArgoCD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 # Create namespace kubectl create namespace argocd # Install ArgoCD kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml # Wait for pods kubectl wait --for=condition=Ready pods --all -n argocd --timeout=300s # Get initial admin password kubectl -n argocd get secret argocd-initial-admin-secret \ -o jsonpath="{.data.password}" | base64 -d # Port forward to access UI kubectl port-forward svc/argocd-server -n argocd 8080:443 Access the UI at https://localhost:8080 with username admin. ...

Deploying new code shouldn’t mean crossing your fingers. Blue-green and canary deployments let you release changes with confidence, validate them with real traffic, and roll back in seconds if something goes wrong. Blue-Green Deployments Blue-green maintains two identical production environments. One serves traffic (blue), while the other stands ready (green). To deploy, you push to green, test it, then switch traffic over. B ┌ │ │ │ └ ┌ │ │ │ └ A ┌ │ │ │ └ ┌ │ │ │ └ e ─ ─ ─ ─ f ─ ─ ─ ─ f ─ ─ ─ ─ t ─ ─ ─ ─ o ─ ─ ─ S ─ e ─ S ─ ─ ─ r ─ A ─ ─ ( T ─ r ─ T ─ ─ A ─ e ─ B v C ─ ─ G i A ─ ─ B v A ─ ─ G v C ─ ─ l 1 T ─ ─ r d N ─ d ─ l 1 N ─ ─ r 1 T ─ d ─ u . I ─ ─ e l D ─ e ─ u . D ─ ─ e . I ─ e ─ e 0 V ─ ─ e e B ─ p ─ e 0 B ─ ─ e 1 V ─ p ─ ) E ─ ─ n ) Y ─ l ─ ) Y ─ ─ n ) E ─ l ─ ─ ─ ─ o ─ ─ ─ ─ o ─ ─ ─ ─ y ─ ─ ─ ─ y ─ ─ ─ ─ m ─ ─ ─ ─ m ─ ─ ─ ─ e ─ ─ ─ ─ e ┐ │ │ │ ┘ ┐ │ │ │ ┘ n ┐ │ │ │ ┘ ┐ │ │ │ ┘ n t t ◄ : ◄ : ─ ─ ─ ─ ┌ │ └ ┌ │ └ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ R ─ ─ R ─ ─ o ─ ─ o ─ ─ u ─ ─ u ─ ─ t ─ ─ t ─ ─ e ─ ─ e ─ ─ r ─ ─ r ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┐ │ ┘ ┐ │ ┘ ◄ ◄ ─ ─ ─ ─ U U s s e e r r s s Kubernetes Implementation 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 # blue-deployment.yaml apiVersion: apps/v1 kind: Deployment metadata: name: app-blue labels: app: myapp version: blue spec: replicas: 3 selector: matchLabels: app: myapp version: blue template: metadata: labels: app: myapp version: blue spec: containers: - name: app image: myapp:1.0.0 ports: - containerPort: 8080 --- # green-deployment.yaml apiVersion: apps/v1 kind: Deployment metadata: name: app-green labels: app: myapp version: green spec: replicas: 3 selector: matchLabels: app: myapp version: green template: metadata: labels: app: myapp version: green spec: containers: - name: app image: myapp:1.1.0 ports: - containerPort: 8080 --- # service.yaml - switch by changing selector apiVersion: v1 kind: Service metadata: name: myapp spec: selector: app: myapp version: blue # Change to 'green' to switch ports: - port: 80 targetPort: 8080 Deployment Script 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 #!/bin/bash set -e NEW_VERSION=$1 CURRENT=$(kubectl get svc myapp -o jsonpath='{.spec.selector.version}') if [ "$CURRENT" == "blue" ]; then TARGET="green" else TARGET="blue" fi echo "Current: $CURRENT, Deploying to: $TARGET" # Update the standby deployment kubectl set image deployment/app-$TARGET app=myapp:$NEW_VERSION # Wait for rollout kubectl rollout status deployment/app-$TARGET --timeout=300s # Run smoke tests against standby kubectl run smoke-test --rm -it --image=curlimages/curl \ --restart=Never -- curl -f http://app-$TARGET:8080/health # Switch traffic kubectl patch svc myapp -p "{\"spec\":{\"selector\":{\"version\":\"$TARGET\"}}}" echo "Switched to $TARGET (v$NEW_VERSION)" Instant Rollback 1 2 3 4 5 6 7 8 9 10 11 12 13 #!/bin/bash # rollback.sh - switch back to previous version CURRENT=$(kubectl get svc myapp -o jsonpath='{.spec.selector.version}') if [ "$CURRENT" == "blue" ]; then PREVIOUS="green" else PREVIOUS="blue" fi kubectl patch svc myapp -p "{\"spec\":{\"selector\":{\"version\":\"$PREVIOUS\"}}}" echo "Rolled back to $PREVIOUS" Canary Deployments Canary deployments route a small percentage of traffic to the new version, gradually increasing if metrics look good. ...