Adjust target group based on the RDS Aurora Endpoints

This Lambda function automatically maintains ALB target group registrations for Aurora cluster instances based on their role (reader/writer).

Functionality

• Dynamically updates ALB target groups with Aurora instance IP addresses
• Supports separate reader and writer endpoint management
• Excludes auto-scaled instances from target registration
• Handles target group registration/deregistration automatically

Environment variables used in the Lambda function

• AURORA_CLUSTER_ID: Aurora cluster identifier
• TARGET_GROUP_ARN: ALB target group ARN to manage
• TARGET_PORT: Database port (default: 3306)
• TYPE: Target type - 'reader' or 'writer' (default: 'reader')

Use Case

Good for NLB used for AWS VPC Endpoints.

Before you do anything in this module

Install pre-commit hooks by running following commands:

brew install pre-commit terraform-docs
pre-commit install

Requirements

No requirements.

Providers

Name	Version
archive	n/a
aws	n/a

Modules

No modules.

Resources

Name	Type
aws_cloudwatch_event_rule.every_minute	resource
aws_cloudwatch_event_target.lambda_target	resource
aws_iam_role.lambda_execution_role	resource
aws_iam_role_policy.lambda_policy	resource
aws_lambda_function.aurora_nlb	resource
aws_lambda_permission.allow_cloudwatch_to_call_lambda	resource
aws_security_group.lambda_sg	resource
archive_file.lambda_zip	data source
aws_iam_policy_document.lambda_assume_role_policy	data source
aws_iam_policy_document.lambda_policy	data source

Inputs

Name	Description	Type	Default	Required
identifier	ID of the Aurora cluster to fetch IP addresses from, or instance identifier for IDS instance	string	n/a	yes
name	Prefixing name for the Lambda function and associated resources	string	n/a	yes
target_group_arn	ARN of the target group to update with Aurora endpoints IP addresses	string	n/a	yes
target_port	Port on which the target group is listening	string	n/a	yes
type	Type of the target group, either 'reader' or 'writer'	string	n/a	yes
vpc_id	VPC ID for Lambda security group	string	n/a	yes
vpc_subnet_ids	Subnet IDs for Lambda to run within the VPC	list(string)	n/a	yes

Outputs

Name	Description
function_name	n/a