Nginx reverse proxy with rate limiting

ratelimit.nginxconf

upstream myapp {
    server 127.0.0.1:8081;
}

limit_req_zone $binary_remote_addr zone=login:10m rate=1r/s;

server {
    listen 443 ssl spdy;
    server_name _;
  
    ssl on;
    ssl_certificate /etc/nginx/ssl/cert.pem;
    ssl_certificate_key /etc/nginx/ssl/cert.key;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers AES256+EECDH:AES256+EDH;
    ssl_session_cache  builtin:1000  shared:SSL:5m;
    ssl_prefer_server_ciphers on;

  
    location / {
        proxy_pass http://myapp;
        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;
    }
    
    location /account/login/ {
        # apply rate limiting
        limit_req zone=login burst=5;
    
        # boilerplate copied from location /
        proxy_pass http://myapp;
        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;
    }
}

yes, it helps to prevent DOS attack from single IP. No matter how much traffic is you are getting from different IPs /users.

All the proxy_set_* boilerplate can be moved to the server or even http blocks as @bitcity suggested:

http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_set_header

Syntax:         proxy_set_header field value;
Default:        proxy_set_header Host $proxy_host;
                proxy_set_header Connection close;
Context:        http, server, location