Tutorial: deploy your application to a minikube cluster

1. Run RubyMine and click New Project on the Welcome Screen.

   

2. In the New Project dialog, select Application in the Rails group Ruby on Rails in the Project Type group on the left pane.

3. Specify the following settings:

   

   • Name: specify a name for the project (rails-helloworld in our case).

   • Location: specify a path to the directory in which you want to create the project. By default, RubyMine creates a directory with the same name as the project.

   • Interpreter: select a Ruby interpreter that you want to use in your project.

   • Rails version: select a Rails version that you want to use in your project. If the Rails gem is not installed in the selected interpreter or the necessary Rails version is missing, click in the field. Wait until RubyMine downloads all available Rails versions and select the necessary version from the dropdown. Click OK to continue.

     

     If the selected version is not installed yet, RubyMine will install it upon project creation.

   • Extra options: provide additional Rails options for project creation in the Extra options field.

     For example, you can specify arguments that you will normally use to append the rails new command: --skip-tests to skip creation of test files, --skip-action-mailer to skip Action Mailer files, --skip-action-cable to skip Action Cable files, and so on.

     To get a full list of Rails options compatible with the Rails version in use, run the rails new --help command.

4. Click Create to close the New Project dialog.

5. RubyMine creates a new Rails application, installs the gem dependencies mentioned in Gemfile, and installs JavaScript dependencies mentioned in the project's package.json file. You can see this process in the Run tool window.

   

6. After installing all dependencies, you can see the project structure in the Project tool window (Alt+1) on the left. On the right, RubyMine automatically opens the main project files in the editor.

   

   If you have Git installed in your operating system, generating a new Rails application also initializes a Git repository. You can learn how to work with Version control systems in RubyMine from the Version control section.

7. Now we have a functioning Rails application. To see it in action, you need to start a web server. Perform the following steps to do this:

   1. Click the Run icon in the upper right corner.

   2. RubyMine will show the process of preparing the application to run.

      

   3. Open http://127.0.0.1:3000 in your browser to see the Rails default information page.

      

Build the Docker image

1. Form the Project view, open Dockerfile in the editor.

2. Edit the file:

   • Change

     ENV RAILS_ENV="production" \ BUNDLE_DEPLOYMENT="1" \ BUNDLE_PATH="/usr/local/bundle" \ BUNDLE_WITHOUT="development"

     to

     ENV RAILS_ENV="development" \ BUNDLE_PATH="/usr/local/bundle"

   • Change

     EXPOSE 80 CMD ["./bin/thrust", "./bin/rails", "server"]

     to

     EXPOSE 3000 CMD ["./bin/rails", "server", "-b", "0.0.0.0", "-p", "3000"]

3. In the gutter inside the Dockerfile, click and select New Run Configuration.

4. In the Edit Run Configuration dialog, specify rails-minikube-app in the Image tag field and rails-minikube in the Container name field. Then, click Run.

RubyMine creates a Dockerfile run configuration, which builds an image from the Dockerfile and then runs a container based on that image. To follow the whole process, open the Log tab in the Services tool window.

Start minikube with the Docker driver

1. Open the Terminal tool window: go to View | Tool Windows | Terminal or press Alt+F12.

2. Run the following command to start a local Kubernetes cluster and instruct minikube to use Docker as the virtualization driver:

   minikube start --driver=docker

3. Verify that your cluster is up and running by using the command:

   minikube status

Add the minikube cluster to RubyMine

1. Open the Services tool window: go to View | Tool Windows | Services or press Alt+8.

2. Select the Kubernetes node, click the Add Cluster button, and then select From Default Directory from the context menu.

   

3. In the Add Clusters dialog, select minikube and click Add Clusters.

   

   The added cluster will become available in the Services tool window.

4. In the Services tool window, right-click the minikube cluster and select Connect Cluster.

   

Load the Docker image into minikube

1. Open the Terminal tool window: go to View | Tool Windows | Terminal or press Alt+F12.

2. Run the following command to build the container image in minikube:

   minikube image load <image tag>

   where <image tag> is the value specified in the Run/Debug configuration as described above. In our example it should be:

   minikube image load hello-world-docker-app

3. Validate that the rails-minikube-app image is available in your cluster by running:

   minikube image ls | grep rails-minikube-app

   You should see docker.io/library/rails-minikube-app:latest in the output.

Create a Deployment manifest

1. In the Project tool window (Alt+1) , right-click the project name and select New | Kubernetes Resource.

   

2. In the New Kubernetes Resource dialog, select the Deployment file type, specify as the manifest name, and press Enter.

   

   If prompted, agree to add the file to Git.

3. Replace the content of the resulting file with the following code:

   apiVersion: apps/v1 kind: Deployment metadata: name: rails-minikube labels: app: rails-minikube spec: replicas: 1 selector: matchLabels: app: rails-minikube template: metadata: name: rails-minikube labels: app: rails-minikube spec: containers: - name: rails-minikube image: rails-minikube-app imagePullPolicy: IfNotPresent ports: - containerPort: 3000 protocol: TCP restartPolicy: Always

4. On the floating toolbar, select the current cluster and namespace, then click Apply to deliver the changes to the local cluster.

Create a Service manifest

1. In the Project tool window (Alt+1) , right-click the project name and select New | Kubernetes Resource.

   

2. In the New Kubernetes Resource dialog, select the Service file type, specify as the manifest name, and press Enter.

   If prompted, agree to add the file to Git.

3. Replace the content of the resulting file with the following code:

   apiVersion: v1 kind: Service metadata: name: rails-minikube spec: selector: app: rails-minikube ports: - protocol: TCP port: 3000 targetPort: 3000 type: NodePort

4. On the floating toolbar, select the current cluster and namespace, then click Apply to deliver the changes to the local cluster.

Access the application

1. Open the file in the editor.

2. Click the Forward Ports inlay hint next to the - containerPort: 8080 property.

3. In the Forward Ports dialog, leave the default values and click Forward.

4. In the file, click the Open in Browser inlay hint.