Reverse proxy configuration

All Amazon Linux 2 and Amazon Linux 2023 platform versions use nginx as their default reverse proxy server. The Tomcat, Node.js, PHP, and Python platform also support Apache HTTPD as an alternative. To select Apache on these platforms, set the ProxyServer option in the aws:elasticbeanstalk:environment:proxy namespace to apache. All platforms enable proxy server configuration in a uniform way, as described in this section.

Elastic Beanstalk configures the proxy server on your environment's instances to forward web traffic to the main web application on the root URL of the environment; for example, http://my-env.elasticbeanstalk.com.

By default, Elastic Beanstalk configures the proxy to forward requests coming in on port 80 to your main web application on port 5000. You can configure this port number by setting the PORT environment property using the aws:elasticbeanstalk:application:environment namespace in a configuration file, as shown in the following example.

option_settings:
  - namespace:  aws:elasticbeanstalk:application:environment
    option_name:  PORT
    value:  <main_port_number>

For more information about setting environment variables for your application, see Option settings.

Your application should listen on the port that is configured for it in the proxy. If you change the default port using the PORT environment property, your code can access it by reading the value of the PORT environment variable. For example, call os.Getenv("PORT") in Go, or System.getenv("PORT") in Java. If you configure your proxy to send traffic to multiple application processes, you can configure several environment properties, and use their values in both proxy configuration and your application code. Another option is to pass the port value to the process as a command argument in the Procfile. For more information see Buildfile and Procfile.

Configuring nginx

Elastic Beanstalk uses nginx as the default reverse proxy to map your application to your Elastic Load Balancing load balancer. Elastic Beanstalk provides a default nginx configuration that you can extend or override completely with your own configuration.

To extend the Elastic Beanstalk default nginx configuration, add .conf configuration files to a folder named .platform/nginx/conf.d/ in your application source bundle. The Elastic Beanstalk nginx configuration includes .conf files in this folder automatically.

~/workspace/my-app/
|-- .platform
|   `-- nginx
|       `-- conf.d
|           `-- myconf.conf
`-- other source files

To override the Elastic Beanstalk default nginx configuration completely, include a configuration in your source bundle at .platform/nginx/nginx.conf:

~/workspace/my-app/
|-- .platform
|   `-- nginx
|       `-- nginx.conf
`-- other source files

If you override the Elastic Beanstalk nginx configuration, add the following line to your nginx.conf to pull in the Elastic Beanstalk configurations for Elastic Beanstalk enhanced health reporting and monitoring, automatic application mappings, and static files.

 include conf.d/elasticbeanstalk/*.conf;

Configuring Apache HTTPD

The Tomcat, Node.js, PHP, and Python platforms allow you to choose the Apache HTTPD proxy server as an alternative to nginx. This isn't the default. The following example configures Elastic Beanstalk to use Apache HTTPD.

option_settings:
  aws:elasticbeanstalk:environment:proxy:
    ProxyServer: apache

~/workspace/my-app/
|-- .ebextensions
|   -- httpd-proxy.config
|-- .platform
|   -- httpd
|      -- conf.d
|         -- port5000.conf
|         -- ssl.conf
-- index.jsp

listen 5000
<VirtualHost *:5000>
  <Proxy *>
    Require all granted
  </Proxy>
  ProxyPass / http://localhost:8080/ retry=0
  ProxyPassReverse / http://localhost:8080/
  ProxyPreserveHost on

  ErrorLog /var/log/httpd/elasticbeanstalk-error_log
</VirtualHost>

~/workspace/my-app/
|-- .ebextensions
|   -- httpd-proxy.config
|-- .platform
|   `-- httpd
|       `-- conf
|           `-- httpd.conf
`-- index.jsp

IncludeOptional conf.d/elasticbeanstalk/*.conf