Passenger + Rails app only works on port 3000

The passenger will launch on port 80, but only the home page (100% HTML) will appear. No other page will be allowed. And even a stranger, all traffic that cannot be resolved is redirected to HTTPS (which of course also cannot be resolved).

It works:

rvmsudo passenger start --daemonize

      

        
        
        
      

    

This does not work:

rvmsudo passenger start --daemonize --port 80

      

        
        
        
      

    

My config.ru is pretty standard too:

require ::File.expand_path('../config/environment',  __FILE__)
run Rails.application

      

        
        
        
      

    

I am using Rails 4.2.0 and Ruby 2.2.2 with Passenger 5.0.7

Does anyone have any idea?

nginx conf:

user www-data;
worker_processes 4;
pid /run/nginx.pid;

events {
    worker_connections 768;
    # multi_accept on;
}

http {
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    # server_tokens off;

    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    ##
    # Gzip Settings
    ##

    gzip on;
    gzip_disable "msie6";

    ##
    # nginx-naxsi config
    ##
    # Uncomment it if you installed nginx-naxsi
    ##

    #include /etc/nginx/naxsi_core.rules;

    ##
    # nginx-passenger config
    ##
    # Uncomment it if you installed nginx-passenger
    ##

    passenger_root /usr/lib/ruby/vendor_ruby/phusion_passenger/locations.ini
    #passenger_ruby /home/ubuntu/.rvm/gems/ruby-2.2.2

      

        
        
        
      

    

app specific conf:

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

server {
    listen 80;
    server_name www.mydomain.com;

    # Tells Nginx to serve static assets from this directory.
    root /var/www/mydomain/public;

    location / {
        # Tells Nginx to forward all requests for www.foo.com
        # to the Passenger Standalone instance listening on port 4000.
        proxy_pass http://127.0.0.1:4000;

        # These are "magic" Nginx configuration options that
        # should be present in order to make the reverse proxying
        # work properly. Also contains some options that make WebSockets
        # work properly with Passenger Standalone. Please learn more at
        # http://nginx.org/en/docs/http/ngx_http_proxy_module.html
        proxy_http_version 1.1;
        proxy_set_header Host $http_host;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_buffering off;
    }
}