How can AWS CDK be used to enable access from the security group of an ECS service to the security group of an RDS instance?

edit

To enable access from the security group of an ECS service to the security group of an RDS instance using AWS CDK, you can follow these steps:

1. Ensure that you have the AWS CDK installed and set up in your environment.

2. Create an RDS instance and an ECS service using the appropriate CDK constructs.

3. Get the security group IDs of both the RDS instance and the ECS service. You can do this by either:

• Running the appropriate AWS CLI command, such as aws ec2 describe-security-groups, to retrieve the security group IDs programmatically.
• Manually navigating to the AWS Management Console for each service and retrieving the security group IDs from the security group settings.

1. Define a new security group rule for the RDS instance's security group, which permits inbound traffic from the ECS service's security group. For example, using TypeScript:

import * as ec2 from 'aws-cdk-lib/aws-ec2';

const rdsSecurityGroup = ec2.SecurityGroup.fromSecurityGroupId(
  this,
  'rds-sg',
  'rds-security-group-id',
);

const ecsServiceSecurityGroup = ec2.SecurityGroup.fromSecurityGroupId(
  this,
  'ecs-sg',
  'ecs-service-security-group-id',
);

rdsSecurityGroup.addIngressRule(
  ecsServiceSecurityGroup,
  ec2.Port.tcp(3306),
  'Allows inbound traffic from ECS service security group',
);

Note that ecs-service-security-group-id and rds-security-group-id should be replaced with the actual security group IDs retrieved in step 3.

1. Deploy the AWS CDK stack containing the updated security group rules. This will apply the new rule to the RDS instance's security group and allow inbound traffic from the ECS service's security group.