REST API design for non-CRUD actions, e.g. save, deploy, execute code

Resource in my REST API context is application code written in some programming language. CRUD operations that can be easily mapped to HTTP verbs are save/edit/delete code. Non-CRUD operations that are difficult to map to HTTP methods are deploy the code on server, execute the code, and undeploy.

Common suggestions I came across in SO are:

1. Restructure the action to appear like a field of a resource, e.g. if your action is to activate an engine, design URI: PATCH engines/123, body: {"status":"active"}
2. Treat the action like a sub-resource, e.g. PUT engines/123/active without a body
3. Use query parameters, e.g. PUT engines/123?activate=true
4. Be pragmatic and go for a non-RESTful, RPC-style URL, e.g. PUT engines/activate?id=123

I am definitely not able to fit deploy/undeploy/execute code actions to a resource as suggested in #1 and #2. Could you please share your opinion how best we can design the APIs for these actions?