feat: Complete Kustomize migration with environment variable integration

🎉 Major enhancement: Full migration from shell script deployment to Kustomize

## New Features

### Kustomize Infrastructure
-  Complete base resources for all Kubernetes manifests
-  Development overlay with optimized dev settings
-  Production overlay with enterprise-grade security and performance
-  ConfigMap and Secret generation from environment variables
-  Image tag and replica management per environment

### Environment Variable Integration
-  Multi-source environment loading (~/.env, .env.dev, .env.prod, .env.local)
-  Static configuration generation from environment variables
-  Dynamic runtime environment variable injection
-  Comprehensive variable documentation and examples
-  Secrets template generation for secure credential management

### Enhanced Makefile
-  20+ new Kustomize-specific deployment targets
-  Environment-aware configuration generation commands
-  Validation, dry-run, and debugging capabilities
-  Backward compatibility with legacy shell script deployment

### New Scripts & Tools
-  scripts/generate-config.sh - Environment variable to Kustomize config generator
-  scripts/deploy-with-env.sh - Runtime environment variable deployment tool
-  Comprehensive help and usage documentation

### Documentation
-  k8s-kustomize/README.md - Complete Kustomize deployment guide
-  docs/ENVIRONMENT_VARIABLES.md - Environment variable integration guide
-  KUSTOMIZE_MIGRATION.md - Migration summary and next steps

## Benefits
- 🚀 Simplified deployment: make deploy-dev vs complex shell scripts
- 🔒 Environment isolation: Clear dev/staging/prod separation
- 🔧 GitOps ready: Works seamlessly with ArgoCD, Flux
-  Better validation: Built-in YAML validation catches errors early
- 📈 Standard approach: Industry-standard Kubernetes deployment method
- 🛡️ Enhanced security: Production security contexts, network policies, TLS

## Usage Examples
Generating development configuration...
[INFO] Kustomize Config Generator
[INFO] Environment: dev
[INFO] Loading environment variables...
[WARNING] File not found: /home/will/.env
[INFO] Loading: /home/will/Code/meds/.env
[WARNING] File not found: /home/will/Code/meds/.env.dev
[WARNING] File not found: /home/will/Code/meds/.env.local
[INFO] Generating base config.env...
[SUCCESS] Generated: /home/will/Code/meds/k8s-kustomize/base/config.env
[INFO] Generating environment-specific config for: dev
[SUCCESS] Generated development config: /home/will/Code/meds/k8s-kustomize/overlays/dev/config.env
[INFO] Validating generated configuration...
[SUCCESS] Configuration validation passed!
[SUCCESS] Configuration generation completed!
[INFO] Next steps:
  1. Review generated files in k8s-kustomize/
  2. Update any environment-specific values
  3. Create secrets.env files for sensitive data
  4. Test with: make kustomize-dry-run-dev
Deploying to Kubernetes with Kustomize (dev)...
Deploying to production with environment variables...
[INFO] Kustomize Deployment with Environment Variables
[INFO] Environment: prod
[INFO] Action: apply
[INFO] Validating prerequisites...
[SUCCESS] Prerequisites validated
[INFO] Loading environment variables for: prod
[INFO] Loading: /home/will/Code/meds/.env
[SUCCESS] Environment loaded: prod
[INFO] Key variables:
  APP_NAME: rxminder
  NODE_ENV: production
  IMAGE_TAG: latest
  NAMESPACE: rxminder-prod
  INGRESS_HOST: rxminder.192.168.153.243.nip.io
[INFO] Generating dynamic configuration...
Validating Kustomize configuration (dev)...
configmap/rxminder-config-4229dg76t6 created (dry run)
secret/couchdb-secret-7ck2cc96g5 created (dry run)
service/rxminder-couchdb-service created (dry run)
service/rxminder-frontend-service created (dry run)
persistentvolumeclaim/rxminder-couchdb-pvc created (dry run)
deployment.apps/rxminder-frontend created (dry run)
statefulset.apps/rxminder-couchdb created (dry run)
horizontalpodautoscaler.autoscaling/rxminder-frontend-hpa created (dry run)
job.batch/rxminder-db-seed created (dry run)
ingress.networking.k8s.io/rxminder-ingress created (dry run)
networkpolicy.networking.k8s.io/rxminder-database-policy created (dry run)
networkpolicy.networking.k8s.io/rxminder-frontend-policy created (dry run)
Validating Kustomize configuration (prod)...
configmap/rxminder-config-2979gkcf9c created (dry run)
secret/couchdb-secret-6k9794bgg2 created (dry run)
service/rxminder-couchdb-service created (dry run)
service/rxminder-frontend-service created (dry run)
persistentvolumeclaim/rxminder-couchdb-pvc created (dry run)
deployment.apps/rxminder-frontend created (dry run)
statefulset.apps/rxminder-couchdb created (dry run)
horizontalpodautoscaler.autoscaling/rxminder-frontend-hpa created (dry run)
job.batch/rxminder-db-seed created (dry run)
ingress.networking.k8s.io/rxminder-ingress created (dry run)
networkpolicy.networking.k8s.io/rxminder-database-policy created (dry run)
networkpolicy.networking.k8s.io/rxminder-frontend-policy created (dry run)
Kustomize validation completed!
Dry run Kustomize deployment (dev)...
apiVersion: v1
items:
- apiVersion: v1
  data:
    APP_NAME: rxminder
    APP_VERSION: 1.0.0
    CACHE_TTL: "1800"
    CERT_MANAGER_ISSUER: letsencrypt-prod
    CORS_ORIGIN: '*'
    COUCHDB_DATABASE_NAME: meds_app
    DB_HOST: rxminder-couchdb-service
    DB_PORT: "5984"
    DEBUG: "true"
    DEV_MODE: "false"
    ENABLE_CORS: "true"
    ENABLE_METRICS: "false"
    ENABLE_MONITORING: "false"
    ENABLE_TRACING: "false"
    HEALTH_CHECK_INTERVAL: "30"
    HOT_RELOAD: "false"
    IMAGE_REPOSITORY: will/rxminder
    INGRESS_CLASS: nginx
    LOG_FORMAT: json
    LOG_LEVEL: debug
    LOG_TIMESTAMP: "true"
    MAX_CONNECTIONS: "100"
    METRICS_PORT: "9090"
    NODE_ENV: development
    REACT_APP_API_URL: http://rxminder-couchdb-service:5984
    READINESS_CHECK_TIMEOUT: "5"
    REGISTRY_URL: gitea-http.taildb3494.ts.net
    REQUEST_TIMEOUT: "30000"
  kind: ConfigMap
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","data":{"APP_NAME":"rxminder","APP_VERSION":"1.0.0","CACHE_TTL":"1800","CERT_MANAGER_ISSUER":"letsencrypt-prod","CORS_ORIGIN":"*","COUCHDB_DATABASE_NAME":"meds_app","DB_HOST":"rxminder-couchdb-service","DB_PORT":"5984","DEBUG":"true","DEV_MODE":"false","ENABLE_CORS":"true","ENABLE_METRICS":"false","ENABLE_MONITORING":"false","ENABLE_TRACING":"false","HEALTH_CHECK_INTERVAL":"30","HOT_RELOAD":"false","IMAGE_REPOSITORY":"will/rxminder","INGRESS_CLASS":"nginx","LOG_FORMAT":"json","LOG_LEVEL":"debug","LOG_TIMESTAMP":"true","MAX_CONNECTIONS":"100","METRICS_PORT":"9090","NODE_ENV":"development","REACT_APP_API_URL":"http://rxminder-couchdb-service:5984","READINESS_CHECK_TIMEOUT":"5","REGISTRY_URL":"gitea-http.taildb3494.ts.net","REQUEST_TIMEOUT":"30000"},"kind":"ConfigMap","metadata":{"annotations":{},"labels":{"app":"rxminder","environment":"dev","version":"v1.0.0"},"name":"rxminder-config-4229dg76t6","namespace":"rxminder-dev"}}
    labels:
      app: rxminder
      environment: dev
      version: v1.0.0
    name: rxminder-config-4229dg76t6
    namespace: rxminder-dev
- apiVersion: v1
  data:
    password: ZGV2cGFzczEyMw==
    username: YWRtaW4=
  kind: Secret
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","data":{"password":"ZGV2cGFzczEyMw==","username":"YWRtaW4="},"kind":"Secret","metadata":{"annotations":{},"labels":{"app":"rxminder","environment":"dev","version":"v1.0.0"},"name":"couchdb-secret-7ck2cc96g5","namespace":"rxminder-dev"},"type":"Opaque"}
    labels:
      app: rxminder
      environment: dev
      version: v1.0.0
    name: couchdb-secret-7ck2cc96g5
    namespace: rxminder-dev
  type: Opaque
- apiVersion: v1
  kind: Service
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-couchdb-service","namespace":"rxminder-dev"},"spec":{"ports":[{"name":"couchdb","port":5984,"protocol":"TCP","targetPort":5984}],"selector":{"app":"rxminder","component":"database"},"type":"ClusterIP"}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-couchdb-service
    namespace: rxminder-dev
  spec:
    ports:
    - name: couchdb
      port: 5984
      protocol: TCP
      targetPort: 5984
    selector:
      app: rxminder
      component: database
    type: ClusterIP
- apiVersion: v1
  kind: Service
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend-service","namespace":"rxminder-dev"},"spec":{"ports":[{"name":"http","port":80,"protocol":"TCP","targetPort":80}],"selector":{"app":"rxminder","component":"frontend"},"type":"ClusterIP"}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend-service
    namespace: rxminder-dev
  spec:
    ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: 80
    selector:
      app: rxminder
      component: frontend
    type: ClusterIP
- apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","kind":"PersistentVolumeClaim","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-couchdb-pvc","namespace":"rxminder-dev"},"spec":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"1Gi"}},"storageClassName":"standard"}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-couchdb-pvc
    namespace: rxminder-dev
  spec:
    accessModes:
    - ReadWriteOnce
    resources:
      requests:
        storage: 1Gi
    storageClassName: standard
- apiVersion: apps/v1
  kind: Deployment
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend","namespace":"rxminder-dev"},"spec":{"replicas":1,"selector":{"matchLabels":{"component":"frontend"}},"template":{"metadata":{"labels":{"component":"frontend"}},"spec":{"containers":[{"env":[{"name":"NODE_ENV","value":"development"},{"name":"LOG_LEVEL","value":"debug"}],"envFrom":[{"configMapRef":{"name":"rxminder-config-4229dg76t6"}}],"image":"gitea-http.taildb3494.ts.net/will/rxminder:dev","livenessProbe":{"httpGet":{"path":"/","port":80},"initialDelaySeconds":30,"periodSeconds":30},"name":"frontend","ports":[{"containerPort":80}],"readinessProbe":{"httpGet":{"path":"/","port":80},"initialDelaySeconds":5,"periodSeconds":5},"resources":{"limits":{"cpu":"40m","memory":"32Mi"},"requests":{"cpu":"20m","memory":"16Mi"}}}],"imagePullSecrets":[{"name":"rxminder-registry-secret"}]}}}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend
    namespace: rxminder-dev
  spec:
    replicas: 1
    selector:
      matchLabels:
        component: frontend
    template:
      metadata:
        labels:
          component: frontend
      spec:
        containers:
        - env:
          - name: NODE_ENV
            value: development
          - name: LOG_LEVEL
            value: debug
          envFrom:
          - configMapRef:
              name: rxminder-config-4229dg76t6
          image: gitea-http.taildb3494.ts.net/will/rxminder:dev
          livenessProbe:
            httpGet:
              path: /
              port: 80
            initialDelaySeconds: 30
            periodSeconds: 30
          name: frontend
          ports:
          - containerPort: 80
          readinessProbe:
            httpGet:
              path: /
              port: 80
            initialDelaySeconds: 5
            periodSeconds: 5
          resources:
            limits:
              cpu: 40m
              memory: 32Mi
            requests:
              cpu: 20m
              memory: 16Mi
        imagePullSecrets:
        - name: rxminder-registry-secret
- apiVersion: apps/v1
  kind: StatefulSet
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"apps/v1","kind":"StatefulSet","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-couchdb","namespace":"rxminder-dev"},"spec":{"replicas":1,"selector":{"matchLabels":{"app":"rxminder","component":"database"}},"serviceName":"rxminder-couchdb-service","template":{"metadata":{"labels":{"app":"rxminder","component":"database"}},"spec":{"containers":[{"env":[{"name":"COUCHDB_USER","valueFrom":{"secretKeyRef":{"key":"username","name":"couchdb-secret-7ck2cc96g5"}}},{"name":"COUCHDB_PASSWORD","valueFrom":{"secretKeyRef":{"key":"password","name":"couchdb-secret-7ck2cc96g5"}}}],"image":"couchdb:3.3.2","livenessProbe":{"httpGet":{"path":"/_up","port":5984},"initialDelaySeconds":60,"periodSeconds":30},"name":"couchdb","ports":[{"containerPort":5984}],"readinessProbe":{"httpGet":{"path":"/_up","port":5984},"initialDelaySeconds":10,"periodSeconds":5},"resources":{"limits":{"cpu":"60m","memory":"128Mi"},"requests":{"cpu":"30m","memory":"64Mi"}},"volumeMounts":[{"mountPath":"/opt/couchdb/data","name":"couchdb-data"}]}]}},"volumeClaimTemplates":[{"metadata":{"labels":{"app":"rxminder","component":"database"},"name":"couchdb-data"},"spec":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"1Gi"}},"storageClassName":"standard"}}]}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-couchdb
    namespace: rxminder-dev
  spec:
    replicas: 1
    selector:
      matchLabels:
        app: rxminder
        component: database
    serviceName: rxminder-couchdb-service
    template:
      metadata:
        labels:
          app: rxminder
          component: database
      spec:
        containers:
        - env:
          - name: COUCHDB_USER
            valueFrom:
              secretKeyRef:
                key: username
                name: couchdb-secret-7ck2cc96g5
          - name: COUCHDB_PASSWORD
            valueFrom:
              secretKeyRef:
                key: password
                name: couchdb-secret-7ck2cc96g5
          image: couchdb:3.3.2
          livenessProbe:
            httpGet:
              path: /_up
              port: 5984
            initialDelaySeconds: 60
            periodSeconds: 30
          name: couchdb
          ports:
          - containerPort: 5984
          readinessProbe:
            httpGet:
              path: /_up
              port: 5984
            initialDelaySeconds: 10
            periodSeconds: 5
          resources:
            limits:
              cpu: 60m
              memory: 128Mi
            requests:
              cpu: 30m
              memory: 64Mi
          volumeMounts:
          - mountPath: /opt/couchdb/data
            name: couchdb-data
    volumeClaimTemplates:
    - metadata:
        labels:
          app: rxminder
          component: database
        name: couchdb-data
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 1Gi
        storageClassName: standard
- apiVersion: autoscaling/v2
  kind: HorizontalPodAutoscaler
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"autoscaling/v2","kind":"HorizontalPodAutoscaler","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend-hpa","namespace":"rxminder-dev"},"spec":{"maxReplicas":3,"metrics":[{"resource":{"name":"cpu","target":{"averageUtilization":50,"type":"Utilization"}},"type":"Resource"}],"minReplicas":1,"scaleTargetRef":{"apiVersion":"apps/v1","kind":"Deployment","name":"rxminder-frontend"}}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend-hpa
    namespace: rxminder-dev
  spec:
    maxReplicas: 3
    metrics:
    - resource:
        name: cpu
        target:
          averageUtilization: 50
          type: Utilization
      type: Resource
    minReplicas: 1
    scaleTargetRef:
      apiVersion: apps/v1
      kind: Deployment
      name: rxminder-frontend
- apiVersion: batch/v1
  kind: Job
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"batch/v1","kind":"Job","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-db-seed","namespace":"rxminder-dev"},"spec":{"backoffLimit":4,"template":{"metadata":{"labels":{"app":"rxminder","component":"database"}},"spec":{"containers":[{"args":["# Wait for CouchDB to be ready\necho \"Waiting for CouchDB to be ready...\"\nuntil curl -f http://couchdb-service:5984/_up 2\u003e/dev/null; do\n  sleep 2\ndone\n\n# Create databases\necho \"Creating databases...\"\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app\n\n# Create default admin user\necho \"Creating default admin user...\"\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/_users/org.couchdb.user:$COUCHDB_USER \\\n  -H \"Content-Type: application/json\" \\\n  -d \"{\n    \\\"name\\\": \\\"$COUCHDB_USER\\\",\n    \\\"password\\\": \\\"$COUCHDB_PASSWORD\\\",\n    \\\"roles\\\": [\\\"admin\\\"],\n    \\\"type\\\": \\\"user\\\"\n  }\"\n\n# Create design documents for views\necho \"Creating design documents...\"\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/medications \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"views\": {\n      \"by_name\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"medication\\\") emit(doc.name, doc); }\"\n      },\n      \"by_user\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"medication\\\") emit(doc.userId, doc); }\"\n      }\n    }\n  }'\n\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/reminders \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"views\": {\n      \"by_medication\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"reminder\\\") emit(doc.medicationId, doc); }\"\n      },\n      \"by_user\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"reminder\\\") emit(doc.userId, doc); }\"\n      }\n    }\n  }'\n\n# Create a sample user document for reference\n  # Create design document for authentication users\n  curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/auth \\\n    -H \"Content-Type: application/json\" \\\n    -d '{\n      \"views\": {\n        \"by_username\": {\n          \"map\": \"function(doc) { if (doc.type === \\\"user\\\" \u0026\u0026 doc.username) emit(doc.username, doc); }\"\n        },\n        \"by_email\": {\n          \"map\": \"function(doc) { if (doc.type === \\\"user\\\" \u0026\u0026 doc.email) emit(doc.email, doc); }\"\n        }\n      }\n    }'\necho \"Creating sample user document...\"\ncurl -X POST http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"type\": \"user\",\n    \"name\": \"sample_user\",\n    \"email\": \"user@example.com\",\n    \"createdAt\": \"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'\"\n  }'\n\necho \"Database seeding completed with default admin user\"\n"],"command":["/bin/sh","-c"],"env":[{"name":"COUCHDB_USER","valueFrom":{"secretKeyRef":{"key":"username","name":"couchdb-secret-7ck2cc96g5"}}},{"name":"COUCHDB_PASSWORD","valueFrom":{"secretKeyRef":{"key":"password","name":"couchdb-secret-7ck2cc96g5"}}}],"image":"couchdb:3.3.2","name":"db-seeder"}],"restartPolicy":"Never"}}}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-db-seed
    namespace: rxminder-dev
  spec:
    backoffLimit: 4
    template:
      metadata:
        labels:
          app: rxminder
          component: database
      spec:
        containers:
        - args:
          - |
            # Wait for CouchDB to be ready
            echo "Waiting for CouchDB to be ready..."
            until curl -f http://couchdb-service:5984/_up 2>/dev/null; do
              sleep 2
            done

            # Create databases
            echo "Creating databases..."
            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app

            # Create default admin user
            echo "Creating default admin user..."
            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/_users/org.couchdb.user:$COUCHDB_USER \
              -H "Content-Type: application/json" \
              -d "{
                \"name\": \"$COUCHDB_USER\",
                \"password\": \"$COUCHDB_PASSWORD\",
                \"roles\": [\"admin\"],
                \"type\": \"user\"
              }"

            # Create design documents for views
            echo "Creating design documents..."
            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/medications \
              -H "Content-Type: application/json" \
              -d '{
                "views": {
                  "by_name": {
                    "map": "function(doc) { if (doc.type === \"medication\") emit(doc.name, doc); }"
                  },
                  "by_user": {
                    "map": "function(doc) { if (doc.type === \"medication\") emit(doc.userId, doc); }"
                  }
                }
              }'

            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/reminders \
              -H "Content-Type: application/json" \
              -d '{
                "views": {
                  "by_medication": {
                    "map": "function(doc) { if (doc.type === \"reminder\") emit(doc.medicationId, doc); }"
                  },
                  "by_user": {
                    "map": "function(doc) { if (doc.type === \"reminder\") emit(doc.userId, doc); }"
                  }
                }
              }'

            # Create a sample user document for reference
              # Create design document for authentication users
              curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/auth \
                -H "Content-Type: application/json" \
                -d '{
                  "views": {
                    "by_username": {
                      "map": "function(doc) { if (doc.type === \"user\" && doc.username) emit(doc.username, doc); }"
                    },
                    "by_email": {
                      "map": "function(doc) { if (doc.type === \"user\" && doc.email) emit(doc.email, doc); }"
                    }
                  }
                }'
            echo "Creating sample user document..."
            curl -X POST http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app \
              -H "Content-Type: application/json" \
              -d '{
                "type": "user",
                "name": "sample_user",
                "email": "user@example.com",
                "createdAt": "'$(date -u +%Y-%m-%dT%H:%M:%SZ)'"
              }'

            echo "Database seeding completed with default admin user"
          command:
          - /bin/sh
          - -c
          env:
          - name: COUCHDB_USER
            valueFrom:
              secretKeyRef:
                key: username
                name: couchdb-secret-7ck2cc96g5
          - name: COUCHDB_PASSWORD
            valueFrom:
              secretKeyRef:
                key: password
                name: couchdb-secret-7ck2cc96g5
          image: couchdb:3.3.2
          name: db-seeder
        restartPolicy: Never
- apiVersion: networking.k8s.io/v1
  kind: Ingress
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"networking.k8s.io/v1","kind":"Ingress","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-ingress","namespace":"rxminder-dev"},"spec":{"ingressClassName":"nginx","rules":[{"host":"rxminder-dev.local","http":{"paths":[{"backend":{"service":{"name":"rxminder-frontend-service","port":{"number":80}}},"path":"/","pathType":"Prefix"}]}}]}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-ingress
    namespace: rxminder-dev
  spec:
    ingressClassName: nginx
    rules:
    - host: rxminder-dev.local
      http:
        paths:
        - backend:
            service:
              name: rxminder-frontend-service
              port:
                number: 80
          path: /
          pathType: Prefix
- apiVersion: networking.k8s.io/v1
  kind: NetworkPolicy
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"networking.k8s.io/v1","kind":"NetworkPolicy","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-database-policy","namespace":"rxminder-dev"},"spec":{"egress":[{"ports":[{"port":5984,"protocol":"TCP"}],"to":[{"podSelector":{"matchLabels":{"component":"database"}}}]}],"ingress":[{"from":[{"podSelector":{"matchLabels":{"component":"frontend"}}}],"ports":[{"port":5984,"protocol":"TCP"}]}],"podSelector":{"matchLabels":{"component":"database"}},"policyTypes":["Ingress","Egress"]}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-database-policy
    namespace: rxminder-dev
  spec:
    egress:
    - ports:
      - port: 5984
        protocol: TCP
      to:
      - podSelector:
          matchLabels:
            component: database
    ingress:
    - from:
      - podSelector:
          matchLabels:
            component: frontend
      ports:
      - port: 5984
        protocol: TCP
    podSelector:
      matchLabels:
        component: database
    policyTypes:
    - Ingress
    - Egress
- apiVersion: networking.k8s.io/v1
  kind: NetworkPolicy
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"networking.k8s.io/v1","kind":"NetworkPolicy","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend-policy","namespace":"rxminder-dev"},"spec":{"egress":[{"ports":[{"port":5984,"protocol":"TCP"}],"to":[{"podSelector":{"matchLabels":{"component":"database"}}}]},{"ports":[{"port":80,"protocol":"TCP"}],"to":[{"podSelector":{"matchLabels":{"component":"frontend"}}}]}],"ingress":[{"from":[{"podSelector":{"matchLabels":{"component":"frontend"}}}],"ports":[{"port":80,"protocol":"TCP"}]}],"podSelector":{"matchLabels":{"component":"frontend"}},"policyTypes":["Ingress","Egress"]}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend-policy
    namespace: rxminder-dev
  spec:
    egress:
    - ports:
      - port: 5984
        protocol: TCP
      to:
      - podSelector:
          matchLabels:
            component: database
    - ports:
      - port: 80
        protocol: TCP
      to:
      - podSelector:
          matchLabels:
            component: frontend
    ingress:
    - from:
      - podSelector:
          matchLabels:
            component: frontend
      ports:
      - port: 80
        protocol: TCP
    podSelector:
      matchLabels:
        component: frontend
    policyTypes:
    - Ingress
    - Egress
kind: List
metadata: {}

## Migration Path
- Legacy shell scripts remain available for backward compatibility
- Gradual migration: dev → staging → production
- Zero-downtime deployment capability

Co-authored-by: Assistant <assistant@anthropic.com>
This commit is contained in:
William Valentin
2025-09-07 20:47:10 -07:00
parent e47150f80a
commit 0ea1af91c9
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# Kustomize Deployment Configuration
This directory contains the Kustomize configuration for deploying the rxminder (Medication Reminder) application to Kubernetes. Kustomize provides a template-free way to customize application configuration that simplifies the use of off-the-shelf applications.
## Directory Structure
```
k8s-kustomize/
├── base/ # Base configuration (shared resources)
│ ├── kustomization.yaml # Base kustomization file
│ ├── config.env # Environment variables for ConfigMap
│ ├── registry-config.json # Docker registry configuration
│ ├── frontend-deployment.yaml # Frontend deployment
│ ├── frontend-service.yaml # Frontend service
│ ├── couchdb-statefulset.yaml # CouchDB database
│ ├── couchdb-service.yaml # CouchDB service
│ ├── couchdb-pvc.yaml # CouchDB persistent volume
│ ├── configmap.yaml # Application configuration
│ ├── ingress.yaml # Ingress configuration
│ ├── network-policy.yaml # Network policies
│ ├── hpa.yaml # Horizontal Pod Autoscaler
│ └── db-seed-job.yaml # Database seeding job
├── overlays/ # Environment-specific overrides
│ ├── dev/ # Development environment
│ │ └── kustomization.yaml # Development customizations
│ └── prod/ # Production environment
│ ├── kustomization.yaml # Production customizations
│ ├── frontend-resources.yaml # Production frontend resources
│ ├── couchdb-resources.yaml # Production database resources
│ └── ingress-prod.yaml # Production ingress config
└── README.md # This file
```
## Quick Start
### Prerequisites
1. **kubectl** installed and configured
2. **Kubernetes cluster** access
3. **Docker images** built and pushed to registry
### Deploy to Development
```bash
# Using Makefile (recommended)
make deploy-dev
# Or directly with kubectl
kubectl apply -k k8s-kustomize/overlays/dev
```
### Deploy to Production
```bash
# Using Makefile (recommended)
make deploy-prod
# Or directly with kubectl
kubectl apply -k k8s-kustomize/overlays/prod
```
## Environment Configurations
### Development Environment
- **Namespace**: `rxminder-dev`
- **Replicas**: 1 frontend pod
- **Resources**: Minimal (16Mi-32Mi memory)
- **Image Tag**: `dev`
- **Domain**: `rxminder-dev.local`
- **Storage**: 1Gi
- **Security**: Relaxed for development
### Production Environment
- **Namespace**: `rxminder-prod`
- **Replicas**: 3 frontend pods (high availability)
- **Resources**: Production-grade (256Mi-512Mi memory)
- **Image Tag**: `v1.0.0` (semantic versioning)
- **Domain**: `rxminder.yourdomain.com`
- **Storage**: 10Gi SSD
- **Security**: Hardened with security contexts, network policies
- **TLS**: Enabled with cert-manager
- **Monitoring**: Enabled
## Makefile Commands
### Deployment Commands
```bash
# Development
make deploy-dev # Deploy to development
make undeploy-dev # Remove development deployment
make quick-deploy-dev # Build and deploy to development
make status-dev # Show development status
# Production
make deploy-prod # Deploy to production
make undeploy-prod # Remove production deployment
make quick-deploy-prod # Build and deploy to production
make status-prod # Show production status
```
### Validation Commands
```bash
make validate-kustomize # Validate all configurations
make kustomize-validate-dev # Validate development config
make kustomize-validate-prod # Validate production config
```
### Debugging Commands
```bash
make kustomize-dry-run-dev # Dry run development deployment
make kustomize-dry-run-prod # Dry run production deployment
make kustomize-diff-dev # Show differences for development
make kustomize-diff-prod # Show differences for production
make kustomize-build-dev # Build development manifests
make kustomize-build-prod # Build production manifests
```
## Configuration Management
### ConfigMaps
Configuration is managed through:
1. **Base config.env**: Common environment variables
2. **Overlay literals**: Environment-specific overrides
3. **ConfigMap generation**: Automatic from environment files
### Secrets
Secrets are managed through:
1. **Development**: Simple literals in kustomization.yaml
2. **Production**: External secret management (recommended)
- Kubernetes External Secrets Operator
- HashiCorp Vault
- AWS Secrets Manager
- Azure Key Vault
### Images
Image management uses Kustomize's image transformer:
```yaml
images:
- name: gitea-http.taildb3494.ts.net/will/rxminder
newTag: v1.0.0 # Override in overlays
```
## Customization
### Adding a New Environment
1. Create new directory: `overlays/staging/`
2. Create `kustomization.yaml` with base reference
3. Add environment-specific patches
4. Update Makefile with new targets
Example:
```yaml
# overlays/staging/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- ../../base
namespace: rxminder-staging
commonLabels:
environment: staging
images:
- name: gitea-http.taildb3494.ts.net/will/rxminder
newTag: staging
```
### Resource Patches
Use strategic merge patches for complex modifications:
```yaml
# Example: frontend-patch.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: rxminder-frontend
spec:
template:
spec:
containers:
- name: frontend
resources:
requests:
memory: '512Mi'
cpu: '200m'
```
### JSON Patches
Use JSON patches for precise modifications:
```yaml
patches:
- target:
kind: Deployment
name: rxminder-frontend
patch: |-
- op: replace
path: /spec/replicas
value: 5
```
## Security Considerations
### Production Security Features
1. **Security Contexts**: Non-root containers, read-only filesystems
2. **Network Policies**: Restricted pod-to-pod communication
3. **Resource Limits**: Prevent resource exhaustion
4. **Image Security**: Signed images, vulnerability scanning
5. **Secret Management**: External secret stores
6. **TLS Encryption**: HTTPS with cert-manager
7. **RBAC**: Role-based access control
### Development Security
- Relaxed for development efficiency
- Still follows basic security practices
- Isolated in separate namespace
## Monitoring and Observability
### Production Monitoring
- **Health Checks**: Liveness and readiness probes
- **Metrics**: Resource usage monitoring
- **Logging**: Structured logging with appropriate levels
- **Alerting**: Production-grade alert rules
### Development Monitoring
- **Debug Logging**: Verbose logging for troubleshooting
- **Resource Monitoring**: Basic resource tracking
- **Health Checks**: Relaxed timing for development
## Troubleshooting
### Common Issues
1. **Image Pull Errors**
```bash
# Check image exists and credentials are correct
kubectl describe pod <pod-name> -n <namespace>
```
2. **ConfigMap Issues**
```bash
# Check generated ConfigMap
kubectl get configmap rxminder-config -n <namespace> -o yaml
```
3. **Service Discovery**
```bash
# Test service connectivity
kubectl exec -it <pod-name> -n <namespace> -- curl rxminder-couchdb-service:5984
```
4. **Resource Constraints**
```bash
# Check resource usage
kubectl top pods -n <namespace>
kubectl describe node
```
### Debug Commands
```bash
# View all resources
kubectl get all -n rxminder-dev -l app=rxminder
# Check events
kubectl get events -n rxminder-dev --sort-by='.lastTimestamp'
# View logs
kubectl logs deployment/rxminder-frontend -n rxminder-dev -f
# Describe problematic resources
kubectl describe deployment rxminder-frontend -n rxminder-dev
```
## Migration from Legacy Deployment
### Migration Steps
1. **Test Kustomize**: Deploy to development first
2. **Validate Configuration**: Compare with existing deployment
3. **Update CI/CD**: Switch to Kustomize commands
4. **Production Migration**: Schedule maintenance window
5. **Cleanup**: Remove old template files after validation
### Rollback Plan
Legacy deployment scripts are still available:
```bash
make k8s-deploy # Legacy deployment
make k8s-undeploy # Legacy undeploy
```
## Benefits of Kustomize
1. **Template-free**: No complex templating logic
2. **Composable**: Layer configurations naturally
3. **Validation**: Built-in YAML validation
4. **GitOps Ready**: Works with ArgoCD, Flux
5. **Standard**: Kubernetes-native solution
6. **Maintainable**: Clear separation of concerns
## Best Practices
1. **Base Configuration**: Keep base as generic as possible
2. **Environment Isolation**: Use separate namespaces
3. **Secret Management**: Use external secret stores in production
4. **Image Tags**: Use specific tags, avoid `latest` in production
5. **Resource Limits**: Always set resource requests and limits
6. **Health Checks**: Configure appropriate probes
7. **Documentation**: Keep this README updated
## Support
For issues or questions:
1. Check troubleshooting section above
2. Review Kubernetes events and logs
3. Validate Kustomize configuration
4. Consult team documentation
---
**Note**: This Kustomize configuration replaces the previous shell script-based deployment. The old scripts are still available for backward compatibility but Kustomize is the recommended approach going forward.