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You can wrap the functions in output apply calls, or use the

_output

variant of functions. This lets you use outputs from other resources. https://www.pulumi.com/docs/concepts/inputs-outputs/

That's not the problem for me. The problem is being able to delay the creation of the policy resource until I have the combined result of all those policy documents.

If the policy is using the outputs from the queues, then it'll wait until the queues are created before providing the final policy

I know, but the problem is that I don't know which queues will exist.

Hmm. So the problem you're facing is the sqs queue method that sets up the subscription can be called an arbitrary amount of times, and you need a way to create the TopicPolicy resource after all calls have been made? + it's in python

Correct

This is an interesting one. I know a workaround for typescript using promises. I'm going to grab a laptop and think about how I'd do it in python

And you can't "attach" statements

Yeah, promises are a language feature of javascript

I'm also going to read on async/await with Python, looks promising

async/await is a possibility, and you can use them inside output

.apply

methods. What I'm thinking is having an output that "finalises" when you call another method after you've finished defining all your sqs queues

Hi @dry-keyboard-94795 thanks for this. I actually have some similar, but I needed a way to automatically finalise everything and trigger the creation of the resources. I finally found what I was looking for in Python. As a reminder, I wanted to be able to subscribe various queues to a topic, without having to be stuck with policy limitations. Here's my proposed solution: 1. There is an

SNS

class to create an SNS topic. 2. That

SNS

class has a method

subscribe

that allows a queue to subscribe to it. 3. The

subscribe

method creates the subscription resource, but does not actually set a policy. Instead it will add that information to a variable that will be used in the future to create the policy resource. Let's call that variable

policy_statements

. Eventually we will have many policy statements, but we can only create the actual policy at the very end. 4. On the

SNS

class we also define a method

create_policy

that will create a policy resource based on the policy statements in

policy_statement

. 5. We use the

atexit

Python package and register the

create_policy

method with it. 6. The

atexit

package guarantees that the

create_policy

will run at the end of the Python program, which means the policy will be created with all the right information because now we have all the information. I haven't tested this with Pulumi yet, but if it works it's a very simple solution for this family of problems and will make me very happy indeed. I'll post here when I have actually tested it.

I don't think atexit will work, as the python program keeps running after the stack is constructed to allow injection via output's

.apply

method

Unfortunately you are right regarding `atexit`:

....
      File "/usr/lib64/python3.11/asyncio/tasks.py", line 659, in ensure_future
        return _ensure_future(coro_or_future, loop=loop)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/usr/lib64/python3.11/asyncio/tasks.py", line 680, in _ensure_future
        return loop.create_task(coro_or_future)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/usr/lib64/python3.11/asyncio/base_events.py", line 434, in create_task
        self._check_closed()
      File "/usr/lib64/python3.11/asyncio/base_events.py", line 519, in _check_closed
        raise RuntimeError('Event loop is closed')
    RuntimeError: Event loop is closed

I believe this error happens because Pulumi's event loop is finished and has moved on, so if you try to do anything else it's already too late. What I needed was an atexit specific for Pulumi.

It's probably easier to just have your own finaliser at the end of your

____main__.py

file