Source: https://memory-beta.fandom.com/wiki/Borg_cube

Source: https://aws.plainenglish.io/kubernetes-architecture-c93cb9c798d8

Live demo: nhs-number

step 1: create a web-based service

import fastapi
import nhs_number

@app.get("/validate", response_model=ValidationResponse)
def validate(number: str = Query(..., description="NHS number to validate")):
    return {"valid": nhs_number.is_valid(number)}

...
                    

$ uvicorn nhs_number_api.main:app --host 0.0.0.0 --port 8888
                    
                  

step 2: create a container

FROM python:3.11-slim
WORKDIR /app
COPY pyproject.toml ./
COPY src ./src
RUN pip install --no-cache-dir .
CMD ["uvicorn", "nhs_number_api.main:app", "--host", "0.0.0.0", "--port", "8888"]
                    

$ docker build -f Containerfile -t nhs-number-api:v0.0.1 .
                    

$ docker run --rm -p 8888:8888 --read-only nhs-number-api:v0.0.1
                    

$ docker push ghcr.io/amadeuspzs/nhs-number-api/nhs-number-api:v0.0.1
            

step 3: deploy the container into a kubernetes (k8s) cluster

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nhs-number-api
spec:
  replicas: 1
  template:
    spec:
      containers:
        - name: nhs-number-api
          image: ghcr.io/amadeuspzs/nhs-number-api/nhs-number-api
          tag: v0.0.1
          ports:
            - containerPort: 8888
              name: http

$ kubectl apply -f deployment.yaml
                    

$ kubectl get pods -n nhsrpysoc
                    

apiVersion: v1
kind: Service
metadata:
  name: nhs-number-api
spec:
  type: ClusterIP
  selector:
    app: nhs-number-api
  ports:
    - name: http
      port: 80
      targetPort: 8888
      protocol: TCP

$ kubectl apply -f service.yaml
                    

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: nhs-number-api
spec:
  rules:
    - host: nhs-rpysoc.rsna.newtonstree.ai
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nhs-number-api
                port:
                  name: http
  tls:
    - hosts:
        - nhs-rpysoc.rsna.newtonstree.ai

$ kubectl apply -f ingress.yaml