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https://github.com/ymtszw/link-preview
"link-preview" service on Cloudflare Workers
https://github.com/ymtszw/link-preview
cloudflare-workers link-preview
Last synced: 3 months ago
JSON representation
"link-preview" service on Cloudflare Workers
- Host: GitHub
- URL: https://github.com/ymtszw/link-preview
- Owner: ymtszw
- License: mit
- Created: 2022-12-09T15:00:16.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-10-28T04:20:13.000Z (3 months ago)
- Last Synced: 2024-10-28T07:40:37.727Z (3 months ago)
- Topics: cloudflare-workers, link-preview
- Language: TypeScript
- Homepage:
- Size: 139 KB
- Stars: 16
- Watchers: 2
- Forks: 23
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
- awesome - ymtszw/link-preview - "link-preview" service on Cloudflare Workers (TypeScript)
README
# link-preview
## What is this?
This is a **light-weight, no-auth "link-preview" service** powered by [Cloudflare Workers](https://www.cloudflare.com/products/workers/)
and [node-html-parser](https://github.com/taoqf/node-html-parser)
- For small- or single-purpose services, Cloudflare Workers are very good environment to work with.
- It enables small-start from free tier, with generous feature offerings
- It allows us exactly what we want in this context: writing in TypeScript, serving public HTTP APIs to the world
- It has well-made development experience: rich documents, wrangler CLI, easy deploy from GitHub Actions, consice user-land directory structure, etc.
- `node-html-parser` fits here as well.
- Reasonably small set of dependencies
- Sufficiently fast (subjectively though, not benchmarked)
- Well-known `querySelector` API
## Why a Service, not a Library?
There are libraries like [link-preview-js](https://github.com/ospfranco/link-preview-js) and they serve the purpose as long as you know what you are doing.
However, there are [gotchas](https://github.com/ospfranco/link-preview-js#gotchas):
- When you attempt to fetch a website of another origin from JavaScript run on a web browser, the browser ask the targeted website for **cross-origin request allowances (CORS; Cross-Origin Resource Sharing)** due to the same-origin policies
- However, not all websites allow CORS. Or rather, most websites just don't (default behavior of ordinary web servers)
- In this scenario, non-browser agent must fetch the website, and pass the result to the initiating script
- **This service exactly does that**
- Fetch websites of another domain on behalf of browser-run script
- Extract essential info for preview purpose from the website (`title` and `url`, optional `description` and `image`)
- Give it back to the requester in JSON format
This service itself **allows** CORS, so you can just pitch requests from whatever environment and they should work.
Also it comes in rescue when your preferred language does not have well-maintained link-preview libraries.
You just need some HTTP client capability and JSON handling.
## How to deploy
1. Prepare your Cloudflare Account
2. Click: [](https://deploy.workers.cloudflare.com/?url=https://github.com/ymtszw/link-preview)
- It should fork this repository and set up your Cloudflare Account, then deploys the service
## Develop locally
```sh
npm install
npm start
```
Then, from another terminal:
```sh
$ curl 'http://localhost:8787?q=https://cloudflare.com' | jq .
{
"title": "Cloudflare - The Web Performance & Security Company",
"description": "Here at Cloudflare, we make the Internet work the way it should. Offering CDN, DNS, DDoS protection and security, find out how we can help your site.",
"url": "https://www.cloudflare.com/",
"image": "https://www.cloudflare.com/static/b30a57477bde900ba55c0b5f98c4e524/Cloudflare_default_OG_.png"
}
```