---
title: Test your Ruby on Rails deployment
linkTitle: Test your deployment
weight: 50
keywords: deploy, kubernetes, ruby
description: Learn how to develop locally using Kubernetes
aliases:
  - /language/ruby/deploy/
  - /guides/language/ruby/deploy/
---

## Prerequisites

- Complete all the previous sections of this guide, starting with [Containerize a Ruby on Rails application](containerize.md).
- [Turn on Kubernetes](/manuals/desktop/features/kubernetes.md#install-and-turn-on-kubernetes) in Docker Desktop.

## Overview

In this section, you'll learn how to use Docker Desktop to deploy your application to a fully-featured Kubernetes environment on your development machine. This lets you to test and debug your workloads on Kubernetes locally before deploying.

## Create a Kubernetes YAML file

In your `docker-ruby-on-rails` directory, create a file named
`docker-ruby-on-rails-kubernetes.yaml`. Open the file in an IDE or text editor and add
the following contents. Replace `DOCKER_USERNAME/REPO_NAME` with your Docker
username and the name of the repository that you created in [Configure CI/CD for
your Ruby on Rails application](configure-github-actions.md).

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: docker-ruby-on-rails-demo
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      service: ruby-on-rails
  template:
    metadata:
      labels:
        service: ruby-on-rails
    spec:
      containers:
        - name: ruby-on-rails-container
          image: DOCKER_USERNAME/REPO_NAME
          imagePullPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
  name: docker-ruby-on-rails-demo
  namespace: default
spec:
  type: NodePort
  selector:
    service: ruby-on-rails
  ports:
    - port: 3000
      targetPort: 3000
      nodePort: 30001
```

In this Kubernetes YAML file, there are two objects, separated by the `---`:

- A Deployment, describing a scalable group of identical pods. In this case,
  you'll get just one replica, or copy of your pod. That pod, which is
  described under `template`, has just one container in it. The
  container is created from the image built by GitHub Actions in [Configure CI/CD for
  your Ruby on Rails application](configure-github-actions.md).
- 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/).

## Deploy and check your application

1. In a terminal, navigate to `docker-ruby-on-rails` and deploy your application to
   Kubernetes.

   ```console
   $ kubectl apply -f docker-ruby-on-rails-kubernetes.yaml
   ```

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

   ```shell
   deployment.apps/docker-ruby-on-rails-demo created
   service/docker-ruby-on-rails-demo created
   ```

2. Make sure everything worked by listing your deployments.

   ```console
   $ kubectl get deployments