README.md

azure-nodejs-demo

Containerized Node.js Demo App for Azure App Service.

Status	Pipeline	Website URL	CDN Endpoint
	dev.yaml	azure-nodejs-demo-dev.azurewebsites.net	nodejsdemo-dev.azureedge.net
	production.yaml	azure-nodejs-demo.azurewebsites.net	nodejsdemo-prod.azureedge.net

Note: the dev.yaml pipeline generally "partially" fails because of security vulnerabilities found when running npm audit. Personally I allow the pipeline to continue and I'm not super concerned because these are only used for local development, e.g. watchers and hot reload.

The production.yaml pipeline only checks for non-development dependency vulnerabilities. And that's usually passing and green :)

Architecture

This demo leverages the Static Content Pattern in Cloud Architecture.

The images and CSS can be served from app itself or pulled from external host, e.g. CDN via ASSETS_BASE_URL environment variable.

Real-World CI/CD Pipelines

In real life you have more than one environment.

• Azure Pipelines Best Practices

  • CI pipeline for feature branches and main
  • Deploy when pushing to main or production branches
  • See ./azure-pipelines for working pipelines and details

• Asset Pipeline
  The included cd.yaml pipeline shows how to upload assets to Blob Storage and purge the Azure CDN cache as part of your deployment process.

• CI/CD & Versioning
  Example versioning and promotion strategies leveraging git commit messages, git tags and package.json.

Azure Demo

• Azure PaaS
  This app is hosted on Web App for Containers

• Azure App Insights integration
  Using appinsights npm package and Express.js middleware with just a few lines of code. See monitor.js

Endpoints

Method	Path	Description
GET	/	root
GET	/health	health check endpoint
POST	/webhooks/test	accepts JSON and logs output

Healthcheck

This is an example healthcheck endpoint with standardized JSON per draft IETF standard

{
  "status": "pass",
  "version": "0.7.1",
  "details": {
    "uptime": {
      "component_type": "system",
      "observed_value": 24208698,
      "human_readable": "0 days, 6 hours, 43 minutes, 28 seconds",
      "observed_unit": "ms",
      "status": "pass",
      "time": "2021-04-12T11:45:32.508Z"
    },
    "env": {
      "WEBSITE_HOSTNAME": "azure-nodejs-demo-dev.azurewebsites.net",
      "WEBSITE_INSTANCE_ID": "03e7481d3d5ff1e67e297f158abd943ce8c8b920fa55dc7bf0565e86886404a8",
      "ASSETS_BASE_URL": "https://nodejsdemo-dev.azureedge.net"
    }
  }
}

Local Docker Development

Note: in local development, I tend to reference the image sha256. But for the docs, we'll leverage a custom tag azure-nodejs-demo to make this doc easier to follow.

Build Image

docker build --tag azure-nodejs-demo .

Run Image

To ensure it runs locally, we need to change the default NODE_ENV to disable https:// redirect. Otherwise browser throws insecure connection message and will not load page.

docker run -it -p 3000:3000 -e NODE_ENV=development azure-nodejs-demo

Target Platform (Edge Case)

In general, you should never publish local builds. In case you decide to do this (I was debugging some Azure Container Registry behavior ;-)) from an m1 Mac, you need to specify Linux as the target platform.

docker build --platform linux/amd64  .