Devops Excellence

# Short-lived credentials (not static keys)
- name: Configure AWS Credentials
  uses: aws-actions/configure-aws-credentials@v4
  with:
    role-to-assume: arn:aws:iam::123456789012:role/GitHubActions
    aws-region: us-east-1
    # OIDC provider - no long-lived secrets!

# Protected environments for production
environment:
  name: production
  # Requires approval + restricts to main branch

# Example: conditional job execution
jobs:
  backend-tests:
    if: contains(github.event.head_commit.modified, 'backend/')
    runs-on: ubuntu-latest

              /\
             /E2E\        <- Few (slow, expensive)
            /------\
           /Integration\ <- Some (medium speed)
          /------------\
         /  Unit Tests  \ <- Many (fast, cheap)
        /----------------\

# Multi-layer security scanning
jobs:
  security:
    runs-on: ubuntu-latest
    steps:
      # SAST - Static code analysis
      - uses: github/codeql-action/init@v3

      # SCA - Dependency vulnerabilities
      - name: Run Trivy
        uses: aquasecurity/trivy-action@master
        with:
          scan-type: 'fs'
          format: 'sarif'

      # Secret scanning
      - name: Gitleaks
        uses: gitleaks/gitleaks-action@v2

      # Container scanning
      - name: Scan Docker image
        run: trivy image myapp:${{ github.sha }}

# Build stage - includes build tools (900MB+)
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production

# Runtime stage - minimal image (<100MB)
FROM node:20-alpine AS runtime
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001
WORKDIR /app
COPY --from=builder --chown=nodejs:nodejs /app/node_modules ./node_modules
COPY --chown=nodejs:nodejs . .
USER nodejs
EXPOSE 3000
CMD ["node", "server.js"]

# Security best practices example
FROM gcr.io/distroless/nodejs20-debian12
COPY --chown=65532:65532 /app /app
USER 65532
EXPOSE 8080

# Version control
.git
.gitignore

# Dependencies (install fresh in container)
node_modules
vendor/
*.pyc
__pycache__

# Secrets and configs
.env
.env.local
secrets/
*.key
*.pem

# Development files
README.md
Dockerfile
docker-compose.yml
.vscode/
.idea/

# Testing and CI
tests/
*.test.js
.github/

# 99.94% of clusters are over-provisioned!
# Average CPU usage: 10%, Memory: 23%
resources:
  requests:
    memory: "128Mi"  # Guaranteed allocation
    cpu: "100m"      # 0.1 CPU cores
  limits:
    memory: "256Mi"  # Maximum allowed
    cpu: "200m"      # Hard cap

# Use tools: Kubecost, Goldilocks, VPA

# Liveness: Is container alive?
livenessProbe:
  httpGet:
    path: /health
    port: 8080
  initialDelaySeconds: 30
  periodSeconds: 10
  timeoutSeconds: 5
  failureThreshold: 3

# Readiness: Can it receive traffic?
readinessProbe:
  httpGet:
    path: /ready
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 5
  successThreshold: 1

# Startup: Has initialization completed?
startupProbe:
  httpGet:
    path: /startup
    port: 8080
  failureThreshold: 30  # 30*10s = 5min for slow starts
  periodSeconds: 10

# Group related resources in single manifest
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  APP_ENV: production
  LOG_LEVEL: info
---
apiVersion: v1
kind: Secret
metadata:
  name: app-secrets
type: Opaque
stringData:
  DATABASE_URL: postgresql://user:pass@db:5432/mydb
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  template:
    spec:
      containers:
      - name: app
        envFrom:
        - configMapRef:
            name: app-config
        - secretRef:
            name: app-secrets

# Pod Security Standards
securityContext:
  runAsNonRoot: true
  runAsUser: 1000
  fsGroup: 1000
  seccompProfile:
    type: RuntimeDefault
  capabilities:
    drop:
    - ALL

# Network Policies (deny-by-default)
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-all-ingress
spec:
  podSelector: {}
  policyTypes:
  - Ingress