#Creating applications from YAML

If you are proficient in YAML syntax and prefer to define configurations outside of forms or pre-defined templates, you can choose the one-click YAML creation method. This approach offers more flexible configuration of basic information and resources for your cloud-native application.

#Precautions

When both Linux and Windows nodes exist in the cluster, to prevent scheduling the application on incompatible nodes, you must configure node selection. For example:

spec:
    spec:
      nodeSelector:
        kubernetes.io/os: linux

#Prerequisites

Ensure the images defined in the YAML can be pulled within the current cluster. You can verify this using the docker pull command.

#Procedure

1. Container Platform, and navigate to Application > Applications.

2. Click Create.

3. Select the Create from YAML.

4. Complete the configuration and click Create.

5. The corresponding Deployment can be viewed on the Details page.

# webapp-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
  labels:
    app: webapp
    env: prod
spec:
  replicas: 3
  selector:
    matchLabels:
      app: webapp
  template:
    metadata:
      labels:
        app: webapp
        tier: frontend
    spec:
      containers:
      - name: webapp
        image: nginx:1.25-alpine
        ports:
        - containerPort: 80
        resources:
          requests:
            cpu: "100m"
            memory: "128Mi"
          limits:
            cpu: "250m"
            memory: "256Mi"
---
# webapp-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: webapp-service
spec:
  selector:
    app: webapp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
  type: ClusterIP