Copybara
Copybara: A tool for transforming and moving code between repositories
...It allows developers to transform, filter, and move code between repositories while maintaining a consistent source of truth. Copybara is particularly useful in workflows where projects maintain both confidential (internal) and public (open source) repositories, enabling controlled synchronization and contribution management between them. The tool supports advanced transformations—such as file relocation, content replacement, and metadata adjustments—defined declaratively in configuration files. It operates in a stateless manner, storing synchronization state within commit metadata to ensure reproducibility and collaboration among multiple users. ...