neondatabase / serverless-cfworker-demo

Demo app for @neondatabase/serverless — details at https://blog.cloudflare.com/neon-postgres-database-from-workers/

@neondatabase/serverless example: query Neon PostgreSQL from a Cloudflare Worker

This repo provides an example of using Neon's @neondatabase/serverless driver package to query PostgreSQL from a Cloudflare Worker, and to cache the results.

The app

The example is a web app that returns a list of your nearest UNESCO World Heritage Sites.

• You can see the app deployed at https://places-neon-demo.pages.dev/ (this is static HTML file presentation/index.html deployed to Cloudflare Pages).

• You can see the JSON data it fetches at https://places.neon-demo.workers.dev/ (this is index.ts deployed as a Cloudflare Worker)

Please note that the UNESCO data is copyright © 1992 – 2022 UNESCO/World Heritage Centre. All rights reserved.

The driver

Neon's @neondatabase/serverless driver is based on and offers the same API as the node-postgres package, which is what you get with npm install pg.

We've simply shimmed the Node libraries it requires, and replaced net.Socket and tls.connect with implementations that encrypt and transfer the data over WebSockets.

Find out more about the driver from the @neondatabase/serverless README on npmjs.com or GitHub.

How to run

To run this app locally:

• Get the data — Download the Excel listing from the UNESCO Syndication page. Open the .xls file and save it as a .csv.

• Create the database — Create a new project in the Neon dashboard, and connect to it securely using psql (substituting your own PostgreSQL connection string, of course):

  mkdir -p $HOME/.postgresql
  
  curl https://letsencrypt.org/certs/isrgrootx1.pem > $HOME/.postgresql/isrgrootx1.pem
  
  psql "postgresql://user:[e-mail]:5432/main?sslmode=verify-full&sslrootcert=$HOME/.postgresql/isrgrootx1.pem"
  

• Load the data — Run the SQL commands in data/import.psql against your database within psql.

• Set environment variables — Create a file .dev.vars, setting the environment variable DATABASE_URL to the PostgreSQL connection string you'll find in your Neon dashboard. That should look something like this:

  DATABASE_URL=postgresql://user:[e-mail]:5432/main

• Install and run

  npm install
  npm install -g wrangler@latest
  
  npx wrangler dev --local

  Edit presentation/index.html to fetch from http://localhost:8787, and open that address in your browser.

• Deploy

  npx wrangler secret put DATABASE_URL # same connection string as in `.dev.vars`
  npx wrangler publish

  (You may then need to edit presentation/index.html to fetch from the deployed endpoint).

Feedback and support

Please visit Neon Community or Support.