reload hooks between uses

[ITProKyle]

Why This Is Needed

Hooks that define a global variable when imported that relies on an environment variable set by Runway (e.g. AWS_DEFAULT_REGION) will retain its original value across uses.

While this is the appropriate functionally from a python standpoint and should be expected, historically this functioned differently do to the use of subprocess.Popen being used to invoke the stacker cli. This created a different process for each region allowing the global values to change.

If merged, this change should be considered for removal in the next major release so that the global variables function as expected.

What Changed

Added

• added try_reload option to runway.util.load_object_from_string that will use importlib.reload to reimport a module if it has already been imported and is not a builtin module

Fixed

• global variables in hooks are now reloaded between uses to mimic functionality present in >1.5.0