https://github.com/remy/cloud-worker
Service Workers, but in "the cloud" ala CloudFlare workers
https://github.com/remy/cloud-worker
Last synced: 2 months ago
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Service Workers, but in "the cloud" ala CloudFlare workers
- Host: GitHub
- URL: https://github.com/remy/cloud-worker
- Owner: remy
- Created: 2018-04-24T18:45:35.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2021-01-14T15:42:07.000Z (over 4 years ago)
- Last Synced: 2025-03-19T02:11:24.362Z (7 months ago)
- Language: JavaScript
- Size: 65.4 KB
- Stars: 25
- Watchers: 3
- Forks: 3
- Open Issues: 0
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Metadata Files:
- Readme: README.md
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README
# Cloud Worker
This project is based on the ideas from the Service Worker specification and the CloudFlare Worker project.
## Outline
Create a single worker file that accepts a `fetch` event and calls `event.respondWith` with a promise (such as another `fetch`).
The module can be used as a standalone server (possibly to test CloudFlare Workers) or as middleware in your own projects or can be invoked manually.
## Installation and usage
Cloud Worker requires [Node](https://nodejs.org) and is installed using npm (which comes with node):
```bash
npm install cloud-worker
```
If you want to only write a cloud worker file, then you can use the prebuilt server in your npm scripts like this:
```json
{
"scripts": {
"start": "worker index.js"
}
}
```
…where `index.js` contains your worker. For example, this [cloud-worker demo](https://cloud-worker.now.sh/) waits 3 seconds then sends all request the response from a example.com ([source code](https://cloud-worker.now.sh/_src)).
Here's some [recipes of what a cloud worker can do](https://developers.cloudflare.com/workers/recipes/a-b-testing/).
## Direct usage
The module can be required and used directly, and the (current) API is:
```
const worker = require('cloud-worker');
```
## Behind the scenes
The cloud worker uses Node's [vm](https://nodejs.org/api/vm.html) module to globally scope all of the required API that the service worker-like script would expect.
It waits for a single `addEventListener` for the `fetch` event and triggers that event when the `worker.handler` function is invoked passing in a `event` that contains a [request](https://developer.mozilla.org/en-US/docs/Web/API/Request) object.
The functionality is provided via the following npm modules:
- `fetch` (and related sub modules including `Request`, `Response`, `Headers`, `FetchError`) via [node-fetch](https://www.npmjs.com/package/node-fetch)
- `Response.redirect` is manually added
- `URL` and `URLSearchParams` via node's internal [url](https://nodejs.org/api/url.html) package
- streams (`ReadableStream`, `WritableStream` and `TransformStream`) via [web-streams-polyfill](https://www.npmjs.com/package/web-streams-polyfill) (though I believe this to be out of date - any user contribution would be grateful here)
- encoding (`TextEncoder` and `TextDecoder`) via [text-encoding](https://www.npmjs.com/package/text-encoding)
- `FetchEvent` is [manually added](https://github.com/remy/cloud-worker/blob/master/lib/FetchEvent.js)
## Licence
- [MIT](https://rem.mit-license.org) / https://rem.mit-license.org