[FEATURE] Expose Workers Cloudflare Region

[ghost]

Right now if I want to know from which cloudflare region any workers instance has been invoked from I need to use something like this

export default {
  async fetch(request) => {
  const res = await fetch('https://cloudflare-dns.com/dns-query', {
    method: 'OPTIONS',
  });
  let region = res.headers.get('cf-ray').split('-')[1]; // LHR
  }
}

Would it be possible to expose cloudflare workers location perhaps from the Environment variables

export default {
  async fetch(request, { CF_REGION }) => {
    console.log(CF_REGION); // LHR
  }
}

[naegelin]

This feature is useful for:

1. sub-requests that need to optimize RTT by talking to region-locked servers (User is from italy, sub request goes to italian server)
2. conducting sub requests inside the GDPR zone to GDPR region locked servers. (User hits a worker in GDPR zone, sub requests guaranteed to stay in GDPR zone)