kubectl create -f .
        

kubectl port-forward svc/webapp-service 8080:3000

http://localhost:8080
        

# kubectl get deployment
kubectl delete deploy webapp-deployment
kubectl delete deploy mogo-deployment

# kubectl get service
kubectl delete service mongo-service
kubectl delete service webapp-service

# kubectl get configmap
kubectl delete configmap mongo-config

# kubectl get secret
kubectl delete secret mongo-secret
        

# mongo-config.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: mongo-config # same as the configuration file name
data:
  mongo-url: mongo-service # service name
        

# mongo-secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: mongo-secret
type: Opaque
data:
  mongo-user: bW9uZ291c2Vy
  mongo-password: bW9uZ29wYXNzd29yZA==
        

# mongo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mogo-deployment
  labels:
    app: mongo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mongo # let deployment know which pod for this deployment
  template: # configuration for pods
    metadata:
      labels:
        app: mongo # each pod has a unique name, but pods can share the same label
    spec:
      containers: # containers in a pod, usually add one container per pod
      - name: mongodb
        image: mongo:5.0 # pull image from Docker Hub
        ports:
        - containerPort: 27017
        env:
        - name: MONGO_INITDB_ROOT_USERNAME
          valueFrom:
            secretKeyRef:
              name: mongo-secret # file name for secret configuration
              key: mongo-user
        - name: MONGO_INITDB_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mongo-secret # file name for secret configuration
              key: mongo-password
---
apiVersion: v1
kind: Service
metadata:
  name: mongo-service # service name accessed by app
spec:
  selector:
    app: mongo # match the pod labels
  ports:
    - protocol: TCP
      port: 27017 # service port
      targetPort: 27017 # pod port
        

# app.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-deployment
  labels:
    app: webapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: webapp # let deployment know which pod for this deployment
  template: # configuration for pods
    metadata:
      labels:
        app: webapp # each pod has a unique name, but pods can share the same label
    spec:
      containers: # containers in a pod, usually add one container per pod
      - name: webapp
        image: nanajanashia/k8s-demo-app:v1.0 # pull image from Docker Hub
        ports:
        - containerPort: 3000
        env:
        - name: USER_NAME
          valueFrom:
            secretKeyRef:
              name: mongo-secret # file name for secret configuration
              key: mongo-user
        - name: USER_PWD
          valueFrom:
            secretKeyRef:
              name: mongo-secret # file name for secret configuration
              key: mongo-password
        - name: DB_URL
          valueFrom:
            configMapKeyRef:
              name: mongo-config # file name for configuration
              key: mongo-url
---
apiVersion: v1
kind: Service
metadata:
  name: webapp-service # service name accessed by app
spec:
  type: NodePort # default is ClusterIP which is an internal service
  selector:
    app: webapp # match the pod labels
  ports:
    - protocol: TCP
      port: 3000 # service port
      targetPort: 3000 # pod port
      nodePort: 30100 # 30000 - 32767, external service