Managing Directories Demo

Organizing and scaling your Kubernetes manifests becomes much simpler when you adopt a consistent directory structure and leverage Kustomize. In this guide, we’ll walk through:

• Defining a clear directory layout
• Deploying resources manually with kubectl
• Introducing Kustomize for centralized and per-directory customization

Directory Layout

Under the k8s/ folder, structure your manifests by component:

k8s/
├── api/
├── cache/
└── db/

Each subfolder contains the YAML files for its service.

Sample Manifests

Database Deployment (db/db-depl.yaml)

apiVersion: apps/v1
kind: Deployment
metadata:
  name: db-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      component: db
  template:
    metadata:
      labels:
        component: db
    spec:
      containers:
      - name: mongo
        image: mongo
        env:
        - name: MONGO_INITDB_ROOT_USERNAME
          valueFrom:
            configMapKeyRef:
              name: db-credentials
              key: username
        - name: MONGO_INITDB_ROOT_PASSWORD
          valueFrom:
            configMapKeyRef:
              name: db-credentials
              key: password

Redis Service (cache/redis-service.yaml)

apiVersion: v1
kind: Service
metadata:
  name: redis-cluster-ip-service
spec:
  type: ClusterIP
  selector:
    component: redis
  ports:
  - port: 6379
    targetPort: 6379

Redis Credentials (cache/redis-config.yaml)

apiVersion: v1
kind: ConfigMap
metadata:
  name: redis-credentials
data:
  username: "redis"
  password: "password123"

Manual Deployment

Apply each directory in sequence:

kubectl apply -f k8s/api
kubectl apply -f k8s/cache
kubectl apply -f k8s/db

Or chain them:

kubectl apply -f k8s/api -f k8s/cache -f k8s/db

Cleaning Up

kubectl delete -f k8s/api -f k8s/cache -f k8s/db

Introducing Kustomize

Kustomize lets you define and compose resources without template syntax. Start by creating a root kustomization.yaml under k8s/:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - api/api-depl.yaml
  - api/api-service.yaml
  - cache/redis-config.yaml
  - cache/redis-depl.yaml
  - cache/redis-service.yaml
  - db/db-config.yaml
  - db/db-depl.yaml
  - db/db-service.yaml

Generate the merged manifest:

kustomize build k8s/

Apply directly to the cluster:

kustomize build k8s/ | kubectl apply -f -

Or use kubectl’s built-in Kustomize support:

kubectl apply -k k8s/

Verify your pods:

kubectl get pods

Per-Directory Kustomization

For better modularity, place a kustomization.yaml in each subfolder.

api/kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - api-depl.yaml
  - api-service.yaml

cache/kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - redis-config.yaml
  - redis-depl.yaml
  - redis-service.yaml

db/kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - db-config.yaml
  - db-depl.yaml
  - db-service.yaml

Finally, update the root kustomization.yaml to reference directories:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - api/
  - cache/
  - db/

Apply all components in one command:

kubectl apply -k k8s/

Confirm everything is running:

kubectl get pods

This scalable structure keeps your manifests organized and ready for production-grade overlays.

Links and References

• Kubernetes Manifests
• Kubectl apply documentation
• Kustomize Official Documentation