nginx.conf

# we'll use 2 processors/core
worker_processes 2;
# we set a new limit for open files for our workers
worker_rlimit_nofile 100000;

# we define how we're going to work 
events {
  # for each worker we'll handle 4000 requests (enquee them)
  worker_connections  4000;
  # we'll accept multiple
  multi_accept on;
  # we'll use epoll as a IO event notification
  use epoll;
}

# our server
http {
  server_tokens off;
  include       /etc/nginx/mime.types;
  default_type  application/octet-stream;
  access_log off;
  open_file_cache max=200000 inactive=20s;
  open_file_cache_valid 30s;
  open_file_cache_min_uses 2;
  open_file_cache_errors on;
  sendfile        on;

  keepalive_timeout  30;
  reset_timedout_connection on;

  gzip  on;
  gzip_http_version 1.0;
  gzip_proxied any;
  gzip_min_length 500;
  gzip_disable "MSIE [1-6]\.";

  # we created that folder because we save our cache in there
  proxy_cache_path /var/lib/nginx/proxy levels=1:2 keys_zone=backcache:8m max_size=50m;
  proxy_cache_key "$scheme$request_method$host$request_uri$is_args$args";
  proxy_cache_valid 404 1m;

  # we'll forward request to our web app at 3000
  upstream app_server {
    server web:3000 fail_timeout=0;
  }

  server {
    # listening at 80
    listen 80;

    # compreess it
    gzip_static on;
    gzip_http_version   1.1;
    gzip_proxied        expired no-cache no-store private auth;
    gzip_disable        "MSIE [1-6]\.";
    gzip_vary           on;

    # some security precautions
    client_body_buffer_size 8K;
    client_max_body_size 20m;
    client_body_timeout 10s;
    client_header_buffer_size 1k;
    large_client_header_buffers 2 16k;
    client_header_timeout 5s;

    keepalive_timeout 40;

    # let's get rid of simple attackers GET /admin/setup.php ....
    location ~ \.(aspx|php|jsp|cgi)$ {
      return 404;
    }
    # let's try to serve static files otherwise forward to app
    try_files $uri $uri/index.html $uri.html @app;
    
    # app is a proxy to our web app
    location @app {
      proxy_set_header X-Url-Scheme $scheme;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $host;
      proxy_redirect off;
      proxy_pass http://app_server;
    }

    # let's serve error pages
    error_page 500 502 503 504 /500.html;
    location = /500.html {
      root /myapp/public;
    }
  }
}