how to centrally define permission model with lake formation in lake house?

You're right that Lake Formation can't directly manage permissions for all data sources (S3, Redshift, RDS) in one place. Here's a concise solution:

For Redshift Data:

• Use Redshift Spectrum to create external tables that point to S3
• Export important Redshift data to S3 using UNLOAD commands
• Apply Lake Formation permissions to these external tables

For RDS Data:

• Use AWS Glue connections to catalog RDS tables
• Set up Athena Federated Query with Lambda connectors
• Query through Athena (respecting Lake Formation permissions)

Relevant Documentation:

• Lake Formation with Redshift Spectrum
• Redshift UNLOAD command
• Athena Federated Query
• AWS Glue connections for RDS
• Lake Formation permissions model

This hybrid approach is currently the best way to implement centralized governance across these different data sources until AWS enhances Lake Formation's direct integration capabilities.