Deploy the application to Kubernetes

Prerequisites:

• Access to the Developer Sandbox for Red Hat OpenShift
• This example uses data from the move2kube-demos repository on GitHub.

Deploy the application to Kubernetes

Now it’s time to deploy the application. Let's get inside the ./myproject directory:

$ cd myproject/
$ ls
Readme.md deploy    scripts   source

Run the builddockerimages.sh script inside the ./myproject/scripts directory. (This step might take some time to complete.)

$ cd scripts
$ ./builddockerimages.sh
[+] Building 1.9s (8/8) FINISHED     
=> [internal] load build definition from Dockerfile                                                                                              0.1s
=> => transferring dockerfile: 747B                                                                                                              0.0s
=> [internal] load .dockerignore                                                                                                                 0.0s
=> => transferring context: 2B                                                                                                                   0.0s
=> [internal] load metadata for registry.access.redhat.com/ubi8/nodejs-12:latest                                                                 1.7s
=> [internal] load build context                                                                                                                 0.0s
=> => transferring context: 868B                                                                                                                 0.0s
=> [1/3] FROM registry.access.redhat.com/ubi8/nodejs-12@sha256:1208ace959a40906e0e0e753b5ed5621c052a5a115e333d70ca8fa5e5c0dc0ca                  0.0s
=> CACHED [2/3] COPY . .                                                                                                                         0.0s
=> CACHED [3/3] RUN npm install                                                                                                                  0.0s
=> exporting to image                                                                                                                            0.0s
=> => exporting layers                                                                                                                           0.0s
=> => writing image sha256:2d560a9a7b40f2d29447b57b619d55a5dd103ae5dd626cd517791f4ae8e61cbb                                                      0.0s
=> => naming to docker.io/library/cfnodejsapp                                                                                                    0.0s
/Users/username/myproject
done

Now, using the pushimages.sh script, we can push our application’s images to the registry we specified during the transform phase. For this step, you need to log in to your Docker registry. To log in to quay.io, run docker login quay.io. To log in to the IBM Cloud us.icr.io registry, refer to the documentation.

$ ./pushimages.sh
Using default tag: latest
The push refers to repository [quay.io/danieloh30/cfnodejsapp]
44682b6a7ca8: Layer already exists 
4d994360499e: Layer already exists 
31226b9a7823: Layer already exists 
718375ad3f65: Layer already exists 
e0b9a99c51af: Layer already exists 
ef5d9ad2a541: Layer already exists 
93749af418e7: Layer already exists 
latest: digest: sha256:197c820069a3691c727db3ccf0d544601035fdca6dba7b96bae16463068a5307 size: 1789

Finally, we will deploy the application with the oc apply command using the YAML files that Move2Kube created for us in the ./myproject/deploy/yamls directory.

We'll use Developer Sandbox for Red Hat OpenShift, a shared multitenant OpenShift cluster that is preconfigured with a set of developer tools. To access the sandbox, visit Get started in the Sandbox and sign up for free.

We will create Kubernetes resources in the OpenShift cluster using the oc command line tool instead of kubectl. If you haven't already installed the oc CLI, follow the instructions in this article: Where can I download the OpenShift command line tool?

Before you deploy the application, you need to log in to the OpenShift cluster on the sandbox. You can copy the oc login command with a valid token (Figure 1).

When you paste the oc login command into your local terminal, the output should look like this:

$ oc login --token=sha256~_4yyHH7hAANsx7BchfB4xkclvdmWUAdt-efqZt0MVOQ --server=https://api.sandbox.x8i5.p1.openshiftapps.com:6443
Logged into "https://api.sandbox.x8i5.p1.openshiftapps.com:6443" as "USERNAME" using the token provided.
You have access to the following projects and can switch between them with 'oc project <projectname>':
  * USERNAME-dev
    USERNAME-stage
Using project "doh-dev".

Replace USERNAME with your account name. Be sure to log in to the USERNAME-dev project.

$ cd ..
$ oc apply -f deploy/yamls
deployment.apps/cfnodejsapp created
imagestream.image.openshift.io/cfnodejsapp-latest created
service/cfnodejsapp created
secret/cfnodejsapp-vcapasenv configured

Now our application is accessible on the cluster. You can check the status of pods by running the following command:

$ oc get pods
NAME                           READY   STATUS    RESTARTS   AGE
cfnodejsapp-7f9ccb98d7-b97xn   1/1     Running   0          7s
cfnodejsapp-7f9ccb98d7-zhdnh   1/1     Running   0          7s

Create a Route to access the application via the FQDN URL:

$ oc expose svc/cfnodejsapp
route.route.openshift.io/cfnodejsapp exposed

You can get the route URL using the following oc command:

$ oc get route
NAME       HOST/PORT                                                    PATH   SERVICES      PORT        TERMINATION   WILDCARD
cfnodejsapp  cfnodejsapp-doh-dev.apps.sandbox.x8i5.p1.openshiftapps.com          cfnodejsapp   port-8080                 None

Access the application using the curl command-line tool:

$ curl cfnodejsapp-doh-dev.apps.sandbox.x8i5.p1.openshiftapps.com
<h1>This is a node server</h1>

You can also make sure that the application deployed successfully via the Topology view on the OpenShift cluster. Let's add a Node.js label to the application pod using the following oc command:

$ oc label deployment/cfnodejsapp app.openshift.io/runtime=nodejs --overwrite 
deployment.apps/cfnodejsapp labeled

In the OpenShift web console, navigate to the Topology view in the Developer perspective. You will see the Node.js icon (Figure 2).

Click on the Open URL icon. This will take you to the application page (Figure 3).

Conclusion

This tutorial demonstrated a simple way to perform a holistic transformation of your Cloud Foundry application to Kubernetes using the Developer Sandbox for Red Hat OpenShift. Visit the Developer Sandbox page to learn more.