scenarios connecting to Amazon RDS MySQL from AWS Lambda: 'Access Denied' despite correct settings
I'm testing a new approach and I tried several approaches but none seem to work. I'm struggling with AWS Lambda not being able to connect to my Amazon RDS MySQL instance. I have a Lambda function written in Node.js (version 14.x), and I'm using the `mysql2` library to connect to the database. The RDS instance is running in the same VPC as the Lambda function, and I have configured the security group to allow inbound traffic on port 3306 from the Lambda's security group. Despite this, I'm getting an 'Access Denied' behavior when trying to connect. Here's the code snippet I'm using to connect: ```javascript const mysql = require('mysql2/promise'); const connection = await mysql.createConnection({ host: 'my-rds-instance.us-east-1.rds.amazonaws.com', user: 'myuser', password: 'mypassword', database: 'mydatabase' }); ``` In the Lambda function's execution role, I’ve attached the policy that allows RDS access, but I still encounter this scenario. I’ve also ensured that the RDS instance is publicly accessible, and the IAM role used by Lambda has the necessary permissions. When I check the VPC settings, the subnet where Lambda is located has a route to the RDS and a NAT gateway configured for outbound internet access. However, the Lambda function still fails with the behavior message: `Access denied for user 'myuser'@'%'`. To troubleshoot this, I've tried logging the behavior details and ensuring that the database user credentials are correct. I've also verified the Lambda function’s VPC settings and security group configurations multiple times. What could I be missing that is causing this access denial? I'm working on a CLI tool that needs to handle this. Any ideas what could be causing this? For reference, this is a production service. What would be the recommended way to handle this?