10 MINUTE EXERCISE
In this lab you will learn about Node.js and will deploy the Node.js and Angular-based web frontend for the CoolStore online shop which uses the API Gateway services you deployed in previous labs.
Node.js is an open source, cross-platform runtime environment for developing server-side applications using JavaScript. Node.js has an event-driven architecture capable of non-blocking I/O. These design choices aim to optimize throughput and scalability in Web applications with many input/output operations, as well as for real-time web applications.
Node.js non-blocking architecture allows applications to process large number of requests (tens of thousands) using a single thread which makes it desirable choice for building scalable web applications.
The Web UI is built using Node.js for server-side JavaScript and AngularJS for client-side JavaScript. Let’s deploy it on OpenShift using the certified Node.js container image available in OpenShift.
In the previous labs, you used the OpenShift {{OPENSHIFT_DOCS_BASE}}/architecture/core_concepts/builds_and_image_streams.html#source-build[Source-to-Image (S2I)^] feature via the Fabric8 Maven Plugin to build a container image from the source code on your laptop. In this lab, you will still use S2I but instead instruct OpenShift to obtain the application code directly from the source repository and build and deploy a container image of it.
The source code for the Node.js Web front-end is available in this Git repository:
<{{WEB_NODEJS_GIT_REPO}}>
Use the OpenShift CLI command to create a new build and deployment for the Web component:
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Name: web
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Version: Nodejs 8
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Git Repository URL: {{LABS_GIT_REPO}}
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Context Dir: web-nodejs
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Labels: app=web,version=1.0
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Tip
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Feeling adventurous? Build and deploy the Web front-end via the OpenShift Web Console instead. To give you a hint, start by clicking on Add to project within the {{COOLSTORE_PROJECT}} project and pick JavaScript and then Node.js in the service catalog. Don’t forget to click on advanced options and set Context Dir to web-nodejs which is the sub-folder of the Git repository where the source code for Web resides. |
$ oc new-app nodejs:8~{{LABS_GIT_REPO}} \
--context-dir=web-nodejs \
--name=web \
--labels=app=web,version=1.0
The --context-dir option specifies the sub-directly of the Git repository which contains the source code for the application to be built and deployed. The --labels allows assigning arbitrary key-value labels to the application objects in order to make it easier to find them later on when you have many applications in the same project.
A build gets created and starts building the Node.js Web UI container image. You can see the build logs using OpenShift Web Console or OpenShift CLI:
$ oc logs -f bc/web
The -f option is to follow the logs as the build progresses. After the building the Node.js Web UI completes, it gets pushed into the internal image registry in OpenShift and then deployed within your project.
In order to access the Web UI from outside (e.g. from a browser), it needs to get added to the load balancer. Run the following command to add the Web UI service to the built-in HAProxy load balancer in OpenShift.
$ oc expose svc/web $ oc get route web
Click on the OpenShift Route of 'Web Service' from the {{OPENSHIFT_CONSOLE_URL}}[OpenShift Web Console^].
You should be able to see the CoolStore with all products and their inventory status.
Well done! You are ready to move on to the next lab.