docker run --rm docker.io/ubuntu/jre:21 java -version

# Dockerfile
FROM docker.io/ubuntu/jre:21
COPY app.jar /app.jar
ENTRYPOINT ["java", "-jar", "/app.jar"]

apiVersion: apps/v1
kind: Deployment
metadata:
  name: java-app
spec:
  replicas: 2
  selector:
    matchLabels:
      app: java-app
  template:
    metadata:
      labels:
        app: java-app
    spec:
      containers:
        - name: app
          image: your-registry/java-app:latest
          ports:
            - containerPort: 8080