Cloudflare workersの空きサブドメイン(○○.workers.dev)を検索

管理画面でも検索できます

See the Pen Cloudflare subdomain checker by John Doe (@04) on CodePen.

hogehoge.workers.devのhogehoge部分を検索できます。

worker.js

export default {
  async fetch(request, env, ctx) {
    const subdomain = new URL(request.url).pathname.slice(1)
    const response = new Response('', await fetch(`https://www.${subdomain}.workers.dev/`))
    response.headers.set('Access-Control-Allow-Origin', '*')
    return response
  }
}

管理画面でサブドメイン変更できます

プログラムでサブドメインを探すこともできます

const n = 2
const chars = '0123456789abcdefghijklmnopqrstuvwxyz'
const charSet = [...Array(n).keys()].map(i => [...chars + (i>0 && i<n-1 ? '-' : '')])
for await (const subdomain of charSet.reduce((a,b)=>a.flatMap(x=>b.map(y=>x+y)),[''])) {
    const res = await fetch('https://dash.cloudflare.com/api/v4/accounts/{account_id}/workers/subdomains/' + subdomain)
    console.log(subdomain, res.status)
    const sleep = msec => new Promise(resolve => setTimeout(resolve, msec));
    await sleep(1000);
}