KCNAApp Delivery & GitOps

App Delivery & GitOps

Cloud native application delivery automates the path from code commit to production.

CI/CD Fundamentals

Continuous Integration (CI): Automatically build, test, and validate every commit.
Continuous Delivery (CD): Automatically deploy validated builds to production (or staging).

Cloud Native CI/CD Tools

Tool	Type
Tekton	Kubernetes-native pipeline primitives
Argo Workflows	DAG-based workflow engine on K8s
GitHub Actions	Cloud CI/CD
Jenkins X	CI/CD for K8s

GitOps

GitOps uses Git as the single source of truth for declarative infrastructure and apps.

Core principles (OpenGitOps):

Declarative — desired state described in Git
Versioned & immutable — Git history is the audit log
Pulled automatically — agents pull and apply changes
Continuously reconciled — agents detect and correct drift

GitOps vs Push-based CD

	Push	GitOps (Pull)
Trigger	CI pushes to cluster	Agent pulls from Git
Credentials	CI has cluster access	Cluster pulls, no external access needed
Drift detection	None	Continuous reconciliation

Argo CD

Argo CD is the leading CNCF GitOps tool:

# Application CR
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: my-app
spec:
  source:
    repoURL: https://github.com/org/gitops-repo
    targetRevision: HEAD
    path: apps/my-app
  destination:
    server: https://kubernetes.default.svc
    namespace: production
  syncPolicy:
    automated:
      prune: true
      selfHeal: true

Flux

Flux is the other major CNCF GitOps tool (graduated). Uses separate controllers (source-controller, kustomize-controller, helm-controller).

Container Image Best Practices

# Multi-stage build — keep images small
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM node:20-alpine AS runner
WORKDIR /app
COPY --from=builder /app/dist ./dist
RUN addgroup -S app && adduser -S app -G app
USER app
EXPOSE 3000
CMD ["node", "dist/index.js"]

Image scanning: Trivy, Snyk, Grype — scan for CVEs before deploying.

Kustomize

Kustomize allows environment-specific overlays without templating:

base/
  deployment.yaml
  service.yaml
  kustomization.yaml
overlays/
  production/
    kustomization.yaml   # patches: replicas=5, image tag
  staging/
    kustomization.yaml   # patches: replicas=1

kubectl apply -k overlays/production/

Summary

GitOps treats Git as the single source of truth; agents continuously reconcile
Argo CD and Flux are the two leading CNCF GitOps tools
Kustomize enables overlay-based config management without templating
Multi-stage Dockerfiles + image scanning are production best practices

Cloud Native Observability

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