Vet execution plan before execution

[carolynvs]

Before running an execution plan, Porter must check that in theory it's possible to run:

• All bundles exist and are pulled
• The bundle uses supported extensions (right now this happens very late, right before we run it)
• The action is valid
• All dependency wiring in the graph is valid, i.e. you aren't passing a credential that doesn't exist to a dependency
• Required credentials and parameters of a dependency in the graph are satisfied either through wiring or because the workflow is supplying values for unmapped params/creds
• All credential and parameter sets used by the graph can be resolved

Before running a bundle in the execution plan, recheck before running that:

• All credential and parameter sets used by the graph from this bundle down can be resolved
• All bundles in the graph from this bundle down can be resolved

ℹ️ Read PEP003 - Advanced Dependencies for context about how dependencies should work, design details, and notes about desired behavior.