daemon off;
#Heroku dynos have 4 cores.
worker_processes 4;

events {
  use epoll;
  accept_mutex on;
  worker_connections 1024;
}

http {
        gzip on;
        gzip_comp_level 2;
        gzip_min_length 512;

  log_format l2met 'measure.nginx.service=$request_time request_id=$http_heroku_request_id';
  access_log logs/nginx/access.log l2met;
  error_log logs/nginx/error.log;

  include mime.types;
  default_type application/octet-stream;
  sendfile on;

  #Must read the body in 5 seconds.
  client_body_timeout 5;

  upstream app_server {
    server unix:/tmp/nginx.socket fail_timeout=0;
  }

  server {
    listen <%= ENV["PORT"] %>;
    server_name _;
    keepalive_timeout 5;

    location / {
      add_header 'Access-Control-Allow-Origin' '*';
      add_header 'Access-Control-Allow-Credentials' 'true';
      add_header 'Access-Control-Expose-Headers' 'Content-Type, Cache-Control, Expires, Etag, Last-Modified';

      if ($request_method = 'OPTIONS') {
        add_header 'Access-Control-Allow-Origin' '*';
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Expose-Headers' 'Content-Type, Cache-Control, Expires, Etag, Last-Modified';

        # Tell browser to cache this pre-flight info for 20 days
        add_header 'Access-Control-Max-Age' 1728000;

        add_header 'Access-Control-Allow-Methods' 'HEAD, GET, POST, PATCH, PUT, DELETE, OPTIONS';
        add_header 'Access-Control-Allow-Headers' 'Content-Type, Authorization, Accept, If-None-Match, If-Modified-Since';

        add_header 'Content-Length' 0;
        add_header 'Content-Type' 'text/plain charset=UTF-8';

        return 204;
      }

      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_redirect off;
      proxy_pass http://app_server;
    }
  }
}