Can I modify deployed configurations in Backstage without starting over?

Unfortunately, you can't directly modify what you've deployed in Backstage once it's created. To achieve that functionality, you would essentially need to write a separate plugin that does several things: it needs to read the current state of your repo, translate that into UI components that display what's already there, and create the IaC code to modify those specific components. This process can become quite involved and may complicate things. Instead, I’d suggest using templates the right way. They’re meant to set up your environment with basic configurations. For more significant changes, consider using modules and establishing regular Terraform plans to keep everything updated while having your developers just adjust a variables file in Git.

It depends quite a bit on your IaC tooling. I’ve set up Backstage to populate a GitOps repository that handles Crossplane configurations. This way, users who have access to the Git repo or any other tooling connected to it can make changes, and Crossplane takes care of syncing those configurations with Kubernetes. It allows for flexibility while managing configurations.

Backstage does have built-in actions for opening pull requests, but you'd have to implement the logic for making changes yourself. This approach could work well for adding new features where you can just upload a new file, like adding an 's3.tf' file for an S3 bucket, or for modifying structured data. If you're looking to modify existing configurations, that might be trickier depending on how you set things up.