rails nginx this conf

nginx.conf

upstream todo {
  server 127.0.0.1:4000;
}

server {
  listen 80 default;

  server_name  todo;

  root /todo/public;
  index index.html index.htm;

  client_max_body_size 4M;

  location ~ ^/(assets|uploads|avatar|favicon) {
    access_log off;
    expires 1y;
    add_header Cache-Control public;
    break;
  }

  location / {
    try_files $uri @example_backend;
  }

  location @example_backend {
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    client_max_body_size 4M;
    client_body_buffer_size 128K;
    proxy_pass http://todo;
  }
  # error_page  404              /404.html;

  # redirect server error pages to the static page /50x.html
  #
  error_page   500 502 503 504  /500.html;
  #location = /500.html {
  #    root   /home/ubuntu/rabel/public;
  #}
}

thin.yml

---
chdir: /home/deployer/app
environment: production
address: 127.0.0.1
port: 3000
timeout: 30
log: log/thin.log
pid: tmp/pids/thin.pid
max_conns: 1024
max_persistent_conns: 100
require: []
wait: 30
servers: 4
daemonize: true