Rails redirect_to重定向到https：// subdomain

Question

I just set up cloudflare ssl on top of my website, and now whenever redirect_to @thing is called in rails the client redirects to https://subdomain/thing/1 rather than https://subdomain.domain.com/thing/1 . not sure if I need to change the cloudflare A records now that ssl is setup because the A record I had before CNAME | subdomain | host CNAME | subdomain | host CNAME | subdomain | host isn't working anymore. If any more information is necessary please let me know!

Rails server is started like so rails s -p 3000 -b0.0.0.0 -e production

DNS records are CNAME | subdomain | host A | domain | serverip A | www | serverip CNAME | subdomain | host A | domain | serverip A | www | serverip

The rails server is running at serverip:3000 and nginx is routing all traffic with the specific subdomain to this port. There are no redirect issues if everything is done using serverip:3000 , but when I do actions using subdomain.domain.com the redirect issues reappear

nginx config ```

server {
    listen 80;
    server_name subdomain.domain.com;
    location / {
        proxy_pass http://subdomain;
    }
}

upstream subdomain {
    server 127.0.0.1:3000;
}

```

Answer 1

you can add following changes routes.rb

constraints subdomain: false do
  get ':any', to: redirect(subdomain: 'www', path: '/%{any}'), any: /.*/
end

You can set the number of top-level domains as an argument to subdomain, eg:

>> app.get('http://www.localhost')
>> app.request.subdomain
=> "" 
>> app.request.subdomain(0)
=> "www" 

This can also be set in an environment file as well:

# config/environments/development.rb
config.action_dispatch.tld_length = 0