fabianbrash/node-function-rhos

Node Function

This repo contains a simple Node Function that can be deployed as a TAP workload.

This function utilizes the buildpacks provided by VMware's open-source Function Buildpacks for Knative project.

Getting Started

To begin editing your function, modify index.js in the root directory.

Inside this file, you will find a function that is invoked by default. For example:

module.exports = async function sampleFunction(context) {
  const ret = 'This is a sample function';
  return new Promise((resolve, reject) => {
    setTimeout(_ => {
      context.log.info('sending response to client')
      resolve(ret);
    }, 500);
  });
};

You may replace the code inside this default function with your logic.

Deploying

Please see DEPLOYING.md on how to build, deploy, and test your newly built function.

Deploying

Prerequisites

In order to further develop this application the following tools may be needed:

• Visual Studio Code or IntelliJ IDEA as Integrated Development Environment (IDE)
• Tanzu Developer Tools plugin for mentioned IDE
• Docker Desktop to execute integration tests or run the application locally
• Curl for local testing
• Pack CLI for local testing

Local

Code Iteration without OCI Images

Use Node directly:

npm install && npm start -- --log-level info

To test if it worked: curl localhost:8080

Docker

Build your image and run it using Docker:

pack build node-function-rhos --path . --buildpack paketo-buildpacks/nodejs --builder paketobuildpacks/builder:base

If using Jammy:

pack build node-function-rhos --path . --buildpack paketo-buildpacks/nodejs --builder paketobuildpacks/builder-jammy-buildpackless-base:latest

Where node-function-rhos is the name of your runnable function image.

Then run via Docker:

docker run -it --rm -p 8080:8080 node-function-rhos

Check for a successful response: curl localhost:8080

Tanzu Application Platform (TAP)

Using the config/workload.yaml it is possible to build, test and deploy this application onto a Kubernetes cluster that is provisioned with Tanzu Application Platform (https://tanzu.vmware.com/application-platform).

NOTE: The provided config/workload.yaml file uses the Git URL for this sample. When you want to modify the source, you must push the code to your own Git repository and then update the spec.source.git information in the config/workload.yaml file.

Deploying to Kubernetes as a TAP workload with Tanzu CLI

You need to select Include TAP deployment resources when generating the project for the steps below to work.

When you are done developing your function, you can simply deploy it using:

tanzu apps workload apply -f config/workload.yaml

If you would like deploy the code from your local working directory you can use the following command:

tanzu apps workload create node-function-rhos -f config/workload.yaml \
  --local-path . \
  --source-image <REPOSITORY-PREFIX>/node-function-rhos-source \
  --type web

Interacting with Tanzu Application Platform

Determine the URL to use for the accessing the app by running:

tanzu apps workload get node-function-rhos

NOTE: This depends on the TAP installation having DNS configured for the Knative ingress.

After deploying your function, you can interact with the function by using:

NOTE: Replace the placeholder with the actual URL.

Using Tilt with a Cluster

You may use tilt >v0.27.2 in combination with TAP's VS Code plugin to enable live development features including Application Live View and Live Update.

Update the allow_k8s_contexts line of the Tiltfile to indicate the Kubernetes context to use.

Update the Tiltfile or set the SOURCE_IMAGE environment variable to indicate the registry path where TAP should store your image.

export SOURCE_IMAGE=registry/project/node-function-rhos
export K8S_TEST_CONTEXT="a-kubernetes-context"
tilt up
tilt down