pip install pytest
python3 test_postgres_container.py

import requests
import yaml
import time
import os

from testcontainers.k3s import K3SContainer
from testcontainers.postgres import PostgresContainer
from kubernetes import client, config

def wait_for_pod_ready(config_dict, namespace="default", timeout=120):
    """
    Wait for all pods in the namespace to be ready.
    """
    from kubernetes import client, config

    config.load_kube_config(config_file=config_dict)
    v1 = client.CoreV1Api()

    end_time = time.time() + timeout
    while time.time() < end_time:
        pods = v1.list_namespaced_pod(namespace=namespace)
        if all(p.status.phase == "Running" for p in pods.items):
            return True
        time.sleep(5)
    raise TimeoutError("Timeout waiting for pods to be ready")


def test_kubernetes_app():
    # Spin up PostgreSQL Container
    with PostgresContainer("postgres:15.0") as postgres:
        postgres_host = postgres.get_container_host_ip()
        postgres_port = postgres.get_exposed_port(5432)

        # Set up Kubernetes cluster
        with K3SContainer() as k3s:
            config_dict=yaml.safe_load(k3s.config_yaml())
            
            config.load_kube_config_from_dict(config_dict)

            os.environ["KUBECONFIG"] = config_dict

            # Apply Kubernetes manifests
            os.system(f"kubectl apply -f kubernetes/app.yaml")
            os.system(f"kubectl apply -f kubernetes/postgres.yaml")

            # Wait for all pods to be ready
            wait_for_pod_ready(config_dict)

            # Send an HTTP request to the application
            response = requests.get("http://localhost:8080/health")
            assert response.status_code == 200
            assert "healthy" in response.text

apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
      - name: postgres
        image: postgres:15.0
        env:
        - name: POSTGRES_USER
          value: "user"
        - name: POSTGRES_PASSWORD
          value: "password"
        - name: POSTGRES_DB
          value: "mydb"

---
apiVersion: v1
kind: Service
metadata:
  name: postgres
spec:
  ports:
  - port: 5432
  selector:
    app: postgres

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: my-app
        image: my-app-image:latest
        ports:
        - containerPort: 8080
        env:
        - name: DATABASE_URL
          value: "postgresql://user:password@postgres:5432/mydb"

---
apiVersion: v1
kind: Service
metadata:
  name: my-app
spec:
  type: NodePort
  selector:
    app: my-app
  ports:
  - protocol: TCP
    port: 8080
    targetPort: 8080