BluAge L3 Workshop Go-Live: Unable to access RDS PostGres database created on default VPC

Based on the information provided, it appears you're experiencing connectivity issues with your RDS PostgreSQL instance in the AWS Blu Age L3 Certification Workshop. This is likely due to security group configuration or network settings. Here are some steps to troubleshoot and resolve the issue:

1. Verify VPC configuration: Ensure that the RDS instance is in the same VPC as your AppStream 2.0 instance. This is crucial for proper connectivity.

2. Check security group rules: The most common connection problem is with the security group's access rules. Make sure the security group assigned to your RDS instance allows inbound traffic on port 5432 (PostgreSQL default port) from your AppStream instance's security group.

3. Public accessibility: If you're trying to access the database from outside the VPC (e.g., using pgAdmin from your local machine), ensure that "Public access" is set to "Yes" for the RDS instance.

4. Add inbound rule: In the RDS instance's security group, add an inbound rule of type PostgreSQL (port 5432) and set the source to the security group ID of your AppStream instance or the "default" security group of the VPC.

5. Check endpoint and credentials: Verify that you're using the correct endpoint, port, database name, username, and password when attempting to connect.

6. Network ACLs: If you've modified the default Network ACLs, ensure they're not blocking the necessary traffic.

If you've confirmed all these settings and still can't connect, you may need to open a support case with AWS, providing your Environment ID and any relevant logs to help diagnose the issue further.

Remember, exposing your database to public access is not recommended for production environments. For the workshop, you might consider creating an EC2 instance in the same VPC as your RDS instance to test connectivity if AppStream access continues to be problematic.

Sources
Troubleshooting connections to your RDS for PostgreSQL instance - Amazon Relational Database Service
Tutorial: Use AWS Blu Age Developer on AppStream 2.0 - AWS Mainframe Modernization
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