- A PersistentVolumeClaim, to define a storage that will be persistent through restarts for the database.
- A Secret, Keeping the database password as an example using secret kubernetes resource.
- A NodePort service, which will route traffic from port 30001 on your host to
  port 8001 inside the pods it routes to, allowing you to reach your app
  from the network.

To learn more about Kubernetes objects, see the [Kubernetes documentation](https://kubernetes.io/docs/home/).

> [!NOTE]
>
> - The `NodePort` service is good for development/testing purposes. For production you should implement an [ingress-controller](https://kubernetes.io/docs/concepts/services-networking/ingress-controllers/).

## Deploy and check your application

1. In a terminal, navigate to `python-docker-dev-example` and deploy your database to
   Kubernetes.

   ```console
   $ kubectl apply -f docker-postgres-kubernetes.yaml
   ```

   You should see output that looks like the following, indicating your Kubernetes objects were created successfully.

   ```console
   deployment.apps/postgres created
   service/postgres created
   persistentvolumeclaim/postgres-pvc created
   secret/postgres-secret created
   ```

   Now, deploy your python application.

   ```console
   kubectl apply -f docker-python-kubernetes.yaml
   ```

   You should see output that looks like the following, indicating your Kubernetes objects were created successfully.

   ```console
   deployment.apps/docker-python-demo created
   service/service-entrypoint created
   ```

2. Make sure everything worked by listing your deployments.

   ```console
   $ kubectl get deployments
   ```

   Your deployment should be listed as follows:

   ```console
   NAME                 READY   UP-TO-DATE   AVAILABLE   AGE
   docker-python-demo   1/1     1            1           48s
   postgres             1/1     1            1           2m39s
   ```

   This indicates all one of the pods you asked for in your YAML are up and running. Do the same check for your services.

   ```console
   $ kubectl get services
   ```

   You should get output like the following.

   ```console
   NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)          AGE
   kubernetes           ClusterIP   10.43.0.1      <none>        443/TCP          13h
   postgres             ClusterIP   10.43.209.25   <none>        5432/TCP         3m10s
   service-entrypoint   NodePort    10.43.67.120   <none>        8001:30001/TCP   79s
   ```

   In addition to the default `kubernetes` service, you can see your `service-entrypoint` service, accepting traffic on port 30001/TCP and the internal `ClusterIP` `postgres` with the port `5432` open to accept connections from you python app.

3. In a terminal, curl the service. Note that a database was not deployed in
   this example.

   ```console
   $ curl http://localhost:30001/
   Hello, Docker!!!
   ```

4. Run the following commands to tear down your application.

   ```console
   $ kubectl delete -f docker-python-kubernetes.yaml
   $ kubectl delete -f docker-postgres-kubernetes.yaml
   ```

## Summary

In this section, you learned how to use Docker Desktop to deploy your application to a fully-featured Kubernetes environment on your development machine.

Related information:

- [Kubernetes documentation](https://kubernetes.io/docs/home/)
- [Deploy on Kubernetes with Docker Desktop](/manuals/desktop/features/kubernetes.md)
- [Swarm mode overview](/manuals/engine/swarm/_index.md)