Health Check - Node.js Example Application

Important

While you can run and interact with this example application on localhost, you cannot take advantage of using the health check functionality with this example application without using OpenShift. For more details on using this example application with a single-node OpenShift cluster, CI/CD deployments, as well as the rest of the runtime, see the Node.js Runtime Guide.

Important

This example application requires Node.js 8.x or greater and npm 5 or greater.

Important

As part of the process of creating this example application using developers.redhat.com/launch or the Fabric8 Launcher tool, set up a project with a CI/CD deployment of this example application. You can see the status of this deployment in your Single-node OpenShift Cluster or OpenShift Online Web Console.

Running the Example Application Locally

To run this example application on your local host:

$ git clone git@github.com:amitdan/saucy-plane-2

$ cd saucy-plane-2

$ npm install && npm start

Interacting with the Example Application Locally

To interact with your example application while it is running, use the form at http://localhost:8080 or the curl command:

$ curl http://localhost:8080/api/greeting
{"content":"Hello, World!"}

$ curl http://localhost:8080/api/greeting?name=Sarah
{"content":"Hello, Sarah!"}

Running the Example Application on a Single-node OpenShift Cluster

If you have a single-node OpenShift cluster, such as Minishift or Red Hat Container Development Kit, installed and running, you can also deploy your example application there. A single-node OpenShift cluster provides you with access to a cloud environment that is similar to a production environment.

To deploy your example application to a running single-node OpenShift cluster:

$ oc login -u developer -p developer

$ oc new-project MY_PROJECT_NAME

$ npm install && npm run openshift

Interacting with the Example Application on a Single-node OpenShift Cluster

To interact with your example application while it is running on a Single-node OpenShift Cluster, you first need to obtain its URL:

$ oc get route ${value-name-app} -o jsonpath={$.spec.host}

${value-name-app}-MY_PROJECT_NAME.LOCAL_OPENSHIFT_HOSTNAME

You can use the form at your application’s URL or you can use the curl command:

$ curl http://${value-name-app}-MY_PROJECT_NAME.LOCAL_OPENSHIFT_HOSTNAME/api/greeting
{"content":"Hello World!"}

$ curl http://${value-name-app}-MY_PROJECT_NAME.LOCAL_OPENSHIFT_HOSTNAME/api/greeting?name=Sarah
{"content":"Hello Sarah!"}

$ curl http://${value-name-app}-MY_PROJECT_NAME.LOCAL_OPENSHIFT_HOSTNAME/api/stop

$ oc get pods -w
NAME                           READY     STATUS    RESTARTS   AGE
${value-name-app}-1-26iy7   1/1       Running   5          18m

When READY changes to 0/1, if you re-execute a curl command to api/greeting or attempt to access the application’s URL, it will be unavailable. When READY changes back to 1/1, curl commands and the application URL will be available again.

More Information

You can learn more about this example application and rest of the Node.js runtime in the Node.js Runtime Guide.