🗃️ Effortless GitHub CDN Setup with Vercel and NodeJS

DIY_GitHub_CDN.md

Effortless GitHub CDN Setup with Vercel and NodeJS

Certain CDNs rely on extended caching, expiring after up to 7 days. Consider crafting your own CDN for GitHub repositories. This gist provides a simplified setup and boilerplate for creating your personal GitHub CDN exclusively using Vercel and NodeJS.

Setup

1. Begin by creating a new repository.
2. Add the essential files: vercel.json and index.js.
3. Deploy your repository effortlessly to Vercel.

Usage

Construct URLs using the format:

https://<CDN>.vercel.app/<USER>/<REPO>/<PATH>

Example:

https://crestatic.vercel.app/creuserr/vatch-lite/vatch-lite.js

No CLI usage, no extra installations—just a hassle-free CDN at your fingertips.

index.js

module.exports = async function(request, response) {
  response.setHeader("Access-Control-Allow-Origin", "*");
  response.setHeader("Content-Type", "text/plain");
  var user = null;
  var repo = null;
  var path = "";
  request.url.split("/").forEach(function(i) {
    if(i.trim().length == 0) return;
    if(user == null) user = i;
    else if(repo == null) repo = i;
    else path += `/${i}`;
  });
  if(path.startsWith("/")) path = path.slice(1);
  if(user == null || repo == null || path.length == 0) return response.status(400).send("Error: Incomplete parameter");
  var url = `https://api.github.com/repos/${user}/${repo}/contents/${path}`;
  try {
    var req = await fetch(url);
    var json = await req.json();
    if(json.content == null) {
      return response.status(400).send("Error: Not found");
    }
    var content = json.content.toString();
    return response.status(200).send(unescape(atob(content.replace(/\n/g, ""))));
  } catch(e) {
    return response.status(400).send(`Error: ${e}`);
  }
}

vercel.json

{
  "version": 2,
  "builds": [{
    "src": "index.js", 
    "use": "@vercel/node"
  }],
  "headers": [{
    "source": "/index.js",
    "headers": [{
      "key": "Access-Control-Allow-Credentials",
      "value": "true"
    }, {
      "key": "Access-Control-Allow-Origin",
      "value": "*"
    }, {
      "key": "Access-Control-Allow-Methods",
      "value": "GET,OPTIONS,PATCH,DELETE,POST,PUT"
    }, {
      "key": "Access-Control-Allow-Headers",
      "value": "X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5, Content-Type, Date, X-Api-Version"
    }]
  }],
  "rewrites": [{
    "source": "/(.*)",
    "destination": "/index.js"
  }]
}