The APPocalypse

The apocalypse split the LP codebase in to app packages. We wish to continue this effort and clean up some remaining parts where the split isn't quite as clean as it should be.

We would then like to build on this in order to actually split the codebase in to separate branches, with the following gains:

• A subset of tests will cover each app, reducing the test cycle.
• Cleaner code with less mixing of concerns.
• Ability to deploy Soyuz without the other apps.

What we are not doing:

• Splitting every app in to a standalone project that can run independent of everything else.
• Splitting the database.

The plan

We will aim to have several clearly defined layers:

• Foundations (possibly more like a set of libraries)
• Registry
• Soyuz
• Everything else

and attempt to only have each item in that list import from the one above.

Where one part can communicate with lower layers we will use soft dependencies, possibly built around a messaging system to allow them to co-operate.

Design

Implementation

Unresolved issues

• Should we try to break the list of external dependencies (sourcedeps.conf and versions.cfg on a per-branch basis)?