Page Contents

Overview

This tutorial shows how to deploy a LoopBack4 application onto Kubernetes on the IBM Cloud.

Prerequisite

You’ll need the following:

  1. Node.js 8.9 or higher
  2. Docker 18.06 or higher
  3. Sign up for an IBM Cloud account if you don’t have one already.
  4. IBM Cloud CLI, Container registry CLI, etc
  5. Kubernetes CLI (kubectl)
  6. LoopBack 4 CLI

Let’s install the LoopBack 4 CLI :

npm i -g @loopback/cli

After you have scaffolded a LoopBack4 application, you’ll get a default endpoint /ping. For simplicity sake, we’ll use this.

Step 1: Scaffold LoopBack 4 app

Run the lb4 app command, and specify all the values provided below.

$ lb4 app
? Project name: lb4-simple-web-app
? Project description: lb4-simple-web-app
? Project root directory: lb4-simple-web-app
? Application class name: Lb4SimpleWebAppApplication
? Select features to enable in the project (Press <space> to select, <a> to toggle all, <i> to invert selection)
 ◉ Enable tslint: add a linter with pre-configured lint rules
 ◉ Enable prettier: install prettier to format code conforming to rules
 ◉ Enable mocha: install mocha to run tests
 ◉ Enable loopbackBuild: use @loopback/build helpers (e.g. lb-tslint)
 ◉ Enable vscode: add VSCode config files
 ◉ Enable docker: include Dockerfile and .dockerignore
 ◉ Enable repositories: include repository imports and RepositoryMixin
 ◉ Enable services: include service-proxy imports and ServiceMixin
(Move up and down to reveal more choices)

The lb4-simple-web-app project is created.

Navigate to the main directory of the project

cd lb4-simple-web-app

Step 2: Run the application locally

In a command window in the main directory of your project, type:

npm start

The application will build, and then the server should start up successfully and display

Server is running at http://[::1]:3000
Try http://[::1]:3000/ping

Open your browser and attempt to access all these urls

http://[::1]:3000/

http://[::1]:3000/ping

http://[::1]:3000/explorer

http://[::1]:3000/openapi.json

lb4_k8s_ibm_cloud_app_website_1.png

Make sure that the application runs well before continuing to the next step.

In the command window, stop the application with

Ctrl + C

Step 3: Build a Docker image

Review the two Docker-related files that have been conveniently provided, .dockerignore and Dockerfile, but leave them unchanged for this tutorial.

Notice the HOST and PORT environment variable values:

ENV HOST=0.0.0.0 PORT=3000

In the package.json file, a docker:build command has been provided.

"docker:build": "docker build -t lb4-simple-web-app ."

Run the command:

npm run docker:build

When it completes, you will see :

Successfully built 7d26df6c1561
Successfully tagged lb4-simple-web-app:latest

You can find your image by typing:

docker images | grep lb4-simple-web-app

It will display something like this :

lb4-simple-web-app   latest 7d26df6c1561

Step 4: Run the application in Docker

In the package.json file, a docker:run command has been provided.

"docker:run": "docker run -p 3000:3000 -d lb4-simple-web-app"

Run the command:

npm run docker:run

Afterwards, type:

docker ps

You should see something like this:


CONTAINER ID   IMAGE                COMMAND          CREATED             STATUS         PORTS
a9962339e863   lb4-simple-web-app   "node ."         8 seconds ago       Up 7 seconds   0.0.0.0:3000->3000/tcp

To see the log output of your container, you can type:

docker logs <container id>    For example : a9962339e863

You should see something like:

Server is running at http://127.0.0.1:3000
Try http://127.0.0.1:3000/ping

Open your browser and attempt to access all these urls

http://127.0.0.1:3000/

http://127.0.0.1:3000/ping

http://127.0.0.1:3000/explorer

http://127.0.0.1:3000/openapi.json

Step 5: Stop the application running in Docker

Find the container id

docker ps | grep lb4

You should see something like this:

a9962339e863        lb4-simple-web-app      "node ."

The leftmost value is the container id.

Type:

docker stop <container id>         For example : a9962339e863

Step 6: Log into IBM Cloud using ibmcloud login command

Use ibmcloud login command to login.

After you’ve been successfully logged in, you’ll see something like:

API endpoint:      https://api.ng.bluemix.net
Region:            us-south
User:              dremond@ca.ibm.com
Account:           Dominique Emond's Account
Resource group:    default
CF API endpoint:
Org:
Space:

Step 7: Log into IBM Cloud Container Registry

ibmcloud cr login

You should see:

Logging in to 'registry.ng.bluemix.net'...
Logged in to 'registry.ng.bluemix.net'.
OK

Step 8: Upload a docker image to the Container Registry

This requires several steps, let’s quickly go through them.

Create a namespace

List your current namespace by typing:

ibmcloud cr namespace-list

If you want to create a new namespace for yourself, you can do so with this command:

ibmcloud cr namespace-add <my_namespace>

Tag your local docker image with the IBM Cloud container registry

Here is the command:

docker tag <source_image>:<tag> registry.<region>.bluemix.net/<my_namespace>/<new_image_repo>:<new_tag>

<source_image>:<tag> is what you have on your machine that you created earlier.

For example : lb4-simple-web-app:latest

registry.<region>.bluemix.net is the container registry region you logged into before.

For example : registry.ng.bluemix.net

<my_namespace> is the namespace you created for yourself

For example : dremond

<new_image_repo>:<new_tag> can be whatever you want it to be; they don’t have to exist yet

For example : loopback4_webapp_repo:1

So, putting these values together, my command will look like this:

docker tag lb4-simple-web-app:latest registry.ng.bluemix.net/dremond/loopback4_webapp_repo:1

Push the local image to the container registry

docker push registry.ng.bluemix.net/dremond/loopback4_webapp_repo:1

You will see a progress bar like this:

The push refers to repository [registry.ng.bluemix.net/dremond/loopback4_webapp_repo]
478b1e842aa3: Pushed
6fd2223ea65e: Pushed
a90c4aba186a: Pushing [============>                                      ]   51.4MB/207.9MB
bb288a38c607: Pushed
53981d6ec3d2: Mounted from dremond/loopback4_repo
b727cac390f6: Mounted fro

Wait until it is completed.

The push refers to repository [registry.ng.bluemix.net/dremond/loopback4_webapp_repo]
478b1e842aa3: Pushed
6fd2223ea65e: Pushed
a90c4aba186a: Pushed
bb288a38c607: Pushed
53981d6ec3d2: Mounted from dremond/loopback4_repo
b727cac390f6: Mounted from dremond/loopback4_repo
df64d3292fd6: Mounted from dremond/loopback4_repo
1: digest: sha256:939ada9d1b7f6a7483aed69dff5ccc28d1931ed249b38d51d34b854b32139177 size: 1787

Verify the image is in the container registry

Type the command :

ibmcloud cr image-list

You should see your image listed.

lb4_k8s_ibm_cloud_container_registry_1.png

Perform a build for the container registry

Perform a build for the container registry.

ibmcloud cr build -t registry.ng.bluemix.net/dremond/loopback4_webapp_repo:1 .

This step may fail if you have exceeded the QUOTA for images in your account. In that case clear up some room and try again.

Wait until it completes.

In your IBM Cloud account, you can view your images here.

Step 9: Point to your Kubernetes Cluster

In a browser, log into your IBM Cloud account, and navigate to Kubernetes > Clusters.

lb4_k8s_ibm_cloud_kubernetes_cluster_1.png

I am choosing my cluster dremondOne in Dallas .

( If you do not have a Kubernetes cluster, you can create one for free by going to https://cloud.ibm.com/containers-kubernetes/overview , clicking on the 'Create a cluster' button, specifying a Resource Group of 'default', a Location of 'Dallas', choosing a Cluster Type of 'Free', and giving it a name. )

Select the ‘Access’ tab of your cluster and follow the instructions.

lb4_k8s_ibm_cloud_cluster_access_1.png

We already logged into the IBM Cloud in an earlier step, so we only need to point to the cluster.

ibmcloud cs region-set us-south
ibmcloud cs cluster-config <Cluster Name>

My cluster name is ‘dremondOne’ so I see this output:

OK
The configuration for dremondOne was downloaded successfully. Export environment variables to start using Kubernetes.

export KUBECONFIG=/Users/dremond/.bluemix/plugins/container-service/clusters/dremondOne/kube-config-hou02-dremondOne.yml

Take the entire ‘export’ line above, and paste it into your command window.

Now you should be able to perform Kubernetes commands like:

kubectl get nodes

You will see output like this:

NAME           STATUS    ROLES     AGE       VERSION
10.76.193.58   Ready     <none>    13d       v1.10.8+IKS

Ok, so now we are ready to deploy our Loopback4 application to Kubernetes!

Step 10: Deploy your Loopback4 application to Kubernetes

Create a deployment

Create a deployment named : lb4-simple-web-app-deployment ; using the image we placed in the container registry.

kubectl run lb4-simple-web-app-deployment --image=registry.ng.bluemix.net/dremond/loopback4_webapp_repo:1

Verify that the pods are running

kubectl get pods

You should see

NAME                                             READY     STATUS             RESTARTS   AGE
lb4-simple-web-app-deployment-5bfcb546d8-r7cs4   1/1       Running            0          7m

A status of ‘Running’ is a good sign. If you have anything other than this, then there may be something wrong with your docker image , or it may have vulnerability issues you need to address.

To see the logs of your pod, type:

kubectl logs lb4-simple-web-app-deployment-5bfcb546d8-r7cs4

and you will see something like this:

Server is running at http://127.0.0.1:3000
Try http://127.0.0.1:3000/ping

Create a service

Expose your deployment with a service named : lb4-simple-web-app-service

kubectl expose deployment/lb4-simple-web-app-deployment --type=NodePort --port=3000 --name=lb4-simple-web-app-service --target-port=3000

Obtain the NodePort of your service

Let’s determine the NodePort of your service.

kubectl describe service lb4-simple-web-app-service

You will see output like this:

Name:                     lb4-simple-web-app-service
Namespace:                default
Labels:                   run=lb4-simple-web-app-deployment
Annotations:              <none>
Selector:                 run=lb4-simple-web-app-deployment
Type:                     NodePort
IP:                       172.21.103.26
Port:                     <unset>  3000/TCP
TargetPort:               3000/TCP
NodePort:                 <unset>  31701/TCP
Endpoints:                172.30.78.136:3000
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

In this case, the NodePort is 31701 .

Obtain the public IP address of the cluster

Let’s determine the public IP address of the cluster

ibmcloud ks workers dremondOne

You should see something like this

OK
ID                        Public IP       Private IP     Machine Type   State    Status
kube-hou02-pa45e...6-w1   184.173.5.187   10.76.193.58   free           normal   Ready

In my case, the public IP is: 184.173.5.187

So now we can formulate the url of our loopback4 application using those two pieces :

http://184.173.5.187:31701

Open your browser and attempt to access all these urls

http://184.173.5.187:31701/

http://184.173.5.187:31701/ping

http://184.173.5.187:31701/explorer

http://184.173.5.187:31701/openapi.json

lb4_k8s_ibm_cloud_app_website_on_cloud_k8s.png

Step 11: View your app in the Kubernetes Dashboard

Let’s go take a look at your application in the Kubernetes dashboard.

Click the ‘Kubernetes Dashboard’ button next to your cluster’s name.

lb4_k8s_ibm_cloud_k8s_dashboard_1.png

Under ‘Workloads’, select ‘Pods’

lb4_k8s_ibm_cloud_k8s_dashboard_2.png

Locate your application, and click on its name

lb4_k8s_ibm_cloud_k8s_dashboard_3.png

If you want to open a shell into the container in the pod, click on the EXEC button.

If you want to view the logs of the container in the pod, click on the LOGS button.

lb4_k8s_ibm_cloud_k8s_dashboard_4.png

So there you have it! You have successfully deployed a Loopback4 application to Kubernetes on the IBM Cloud.

References