Nginx捕获所有域名，然后添加www，如果不存在

This setup is for multiple domain sharing a single CMS platform. It will allow any domain to point to my server ip.

I can use nginx server_name _; to catch all.

But then I would like to 301 redirect to www (appending www. infront) if www is not present. If www is present, it's fine.

How can i achieve this?

I have solved this by using following nginx server configuration.

server {
    listen 80 default_server;
    server_name ~^(?!www\.)(?<domain>.+)$;
    return 301 $scheme://www.$domain$request_uri;
}

server {
    listen 80;
    server_name ~^(?<domain>.+)$;
    root /home/wwwroot/web;
    ..
    ..
}

This will allow any domain and 301 redirect to www.

You can catch the without www and redirect to www with this

server {
    listen       80;
    server_name  example.com;
    return       301 http://www.example.com$request_uri;
}


server {
  listen 80;
  server_name www.example.com;
  root /path/to/site;
  # Extra conf here.
}