NGINX Configuration

NGINX Config

NGINX configuration for our production / staging AWS Elastic Beanstalk Environment. This is all done using .ebextension-files. This just documents the final result. The file handling this configuration process is:

.ebextensions/03nginx.config

NGINX on Elastic Beanstalk

On our Elastic Beanstalk instances, the user's configuration files for NGINX are found in:

/etc/nginx/conf.d

Another file then picks up these modular configurations and includes them in the main configuration:

/etc/nginx/nginx.config

Default webapp configuration

The default NGINX configuration Elastic Beanstalk uses to serve our webapp:

/etc/nginx/conf.d/webapp_healthd.conf

This file is a symlink to the place from where Elastic Beanstalk then launches NGINX:

/opt/elasticbeanstalk/support/conf/webapp_healthd.conf

Warning: this is likely to change when Amazon updates their infrastructure stack (e.g. new Ruby version, new NGINX version)

Our Custom Configuration

Modular Configuration

To prevent timeout when users upload larger files / multiple files, we increase the client_max_body_size value by adding this file:

/etc/nginx/conf.d/proxy.conf

Webapp Configuration

Robots.txt

We serve our robots.txt as a static file with NGINX:

location /robots.txt {
  alias /var/app/current/public/robots.txt;
}

CORS Headers for assets

Our assets are served via CDN. To have modern browsers (Chrome, Firefox) allow our fonts, we need CORS headers on the assets:

location /assets {
  alias /var/app/current/public/assets;
  gzip_static on;
  gzip on;
  expires max;
  add_header Cache-Control public;
  add_header Access-Control-Allow-Origin *;
}

Final configuration

On depoy, we replace Elastic Beanstalk's default etc/nginx/conf.d/webapp_healthd.conf file with our custom webapp_healthd.conf configuration file and restart NGINX.

Contents of our configuration file:

upstream my_app {
  server unix:///var/run/puma/my_app.sock;
}

log_format healthd '$msec"$uri"'
                '$status"$request_time"$upstream_response_time"'
                '$http_x_forwarded_for';

server {
  listen 80;
  server_name _ localhost; # need to listen to localhost for worker tier

  if ($time_iso8601 ~ "^(\d{4})-(\d{2})-(\d{2})T(\d{2})") {
    set $year $1;
    set $month $2;
    set $day $3;
    set $hour $4;
  }

  access_log  /var/log/nginx/access.log  main;
  access_log /var/log/nginx/healthd/application.log.$year-$month-$day-$hour healthd;


  location /robots.txt {
    alias /var/app/current/public/robots.txt;
  }

  location / {
    proxy_pass http://my_app; # match the name of upstream directive which is defined above
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }

  location /assets {
    alias /var/app/current/public/assets;
    gzip_static on;
    gzip on;
    expires max;
    add_header Cache-Control public;
    add_header Access-Control-Allow-Origin *;
  }

  location /public {
    alias /var/app/current/public;
    gzip_static on;
    gzip on;
    expires max;
    add_header Cache-Control public;
  }
}

With this configuration in place, we use another Elastic Beanstalk command to restart NGINX:

container_commands:
  01_reload_nginx:
	command: "sudo service nginx reload"