2.    Create a security group for the load balancer.
Configure the inbound and outbound rules for the security group as needed and record the associated security group ID for future reference.

Add configuration parameters to your configuration file. The following sample configuration includes two option_settings that modify the default behavior of the Elastic Beanstalk service when deploying an Elastic Beanstalk application to a load-balancing, auto-scaling environment:

• aws:elb:loadbalancer: ManagedSecurityGroup
  This option specifies that the Elastic Beanstalk service should not create a new security group for the load balancer and adds a rule to EC2 security groups to ensure that connections are accepted from the security group with the security group ID that you created in step 2 (represented by the placeholder sg-xxxxxxxx).
• aws:elb:loadbalancer: SecurityGroups
  This option specifies that the Elastic Beanstalk service should update the load balancer to use the security group with the security group ID that you created in Step 2 (represented by the placeholder sg-xxxxxxxx).

Contents of sample configuration file elbsg.config:

Scenarios for deploying Elastic Beanstalk applications using custom application deployment options in a configuration file

Creating a new Elastic Beanstalk environment

When you create a new Elastic Beanstalk environment using the configuration information described here, the Elastic Beanstalk service will configure the load balancer to use the security group that matches the security group ID provided in your configuration file instead of automatically creating and assigning a new security group to the load balancer.

Updating an existing Elastic Beanstalk environment

You can also update an existing Elastic Beanstalk environment by adding custom configuration options to an Elastic Beanstalk application deployment file. In the scenario described in this article, the Elastic Beanstalk service would delete the existing ELB security group and update the load balancer to use the security group that matches the security group ID provided in your configuration file.