Caddy v2.1 CORS whitelist

Caddyfile

(cors) {
  @origin{args.0} header Origin {args.0}
  header @origin{args.0} Access-Control-Allow-Origin "{args.0}"
}
myawesomewebsite.com {
  root * /srv/public/
  file_server
  header Access-Control-Allow-Methods "POST, GET, OPTIONS"
  header Access-Control-Allow-Headers "*"
  import cors https://member.myawesomewebsite.com
  import cors https://customer.myawesomewebsite.com
}