Now AWS supports setting up connectivity between your RDS database and EC2 compute instance in 1-click

This eliminates the additional networking tasks such as setting up a VPC, security groups, subnets, and ingress/egress rules manually to establish a connection between your application and database. It improves productivity for new users and application developers who can now quickly launch a database instance and seamlessly connect to an application on a compute instance within minutes.

Watch below video- RDS config details and connectivity to EC2 instance.

When you choose Connect to an EC2 compute resource, RDS sets the following options automatically. You can't change these settings unless you choose not to set up connectivity with an EC2 instance by choosing Don't connect to an EC2 compute resource.

Additional prerequisites
Before you create your DB instance, consider the following additional prerequisites:

• If you are connecting to AWS using AWS Identity and Access Management (IAM) credentials, your AWS account must have IAM policies that grant the permissions required to perform Amazon RDS operations. For more information, see Identity and access management for Amazon RDS.

If you are using IAM to access the Amazon RDS console, you must first sign on to the AWS Management Console with your IAM user credentials. Then go to the Amazon RDS console at https://console.aws.amazon.com/rds/.

• If you want to tailor the configuration parameters for your DB instance, you must specify a DB parameter group with the required parameter settings. For information about creating or modifying a DB parameter group, see Working with parameter groups.

• Determine the TCP/IP port number to specify for your DB instance. The firewalls at some companies block connections to the default ports for RDS DB instances. If your company firewall blocks the default port, choose another port for your DB instance.