InvocationContext Extensibility

[peterallenwebb]

Short description

A couple of months ago, we added InvocationContext, a cross-thread context manager supporting isolation between dbt invocations. Now we want to support extensions and modifications of its runtime behavior without requiring changes in dbt-common. This will mean designing and implementing a general mechanism for registering and using context objects. Uses cases include:

• Environment variable cache (originally added for performance reasons)
• Flags object
• Relation cache
• invocation_id
• EventManager
• Adapter manager
• Record/Replay manager
• Most other objects currently implemented as global variables in dbt

The key will be to provide a way to register and manage the lifetimes of these objects with the InvocationContext, while allowing them to be defined and implemented in the libraries that depend on dbt-common.

Acceptance criteria

TBD

Suggested Tests

TBD

Impact to Other Teams

None

Will backports be required?

No