Migrations

flowchart LR
    Composition -->|contains| Overlay -->|references location of| Pattern\nConfiguration -->|references location of| Pattern\nTemplate

• The anchor for changes is:

  - The location of the - the hashed value of the composition and its overlays - This detects changes to overridden values and changes to pattern configuration locations (like a more up-to-date git reference)

• What to store

  - Store the composition location - Store the composition contents hash to detect if its overrides have changed - This catches when the pattern configuration location changes (like a more up-to-date git reference) - For each pattern - Store the requested location from the overlay - This will provide information if a specific version of the pattern was requested - The location may be very generic (like a GitHub repo), or very specific (commit 123456 of the repo) - Store the location used: - For git URLs, this would be a URL to a specific reference - Will need to be able to resolve the specificity of Git references - branches -> current commit - tags -> commit