This message was deleted.

another use case, I want to compile JSON.stringify() for new pulumi.asset.StringAsset(JSON), to write to my storage account with some Output<string> value. Any suggestions? @colossal-beach-47527

I ran into the same thing when I first started using Pulumi, and I had a lot of trouble getting used to the idea that promises don't work very well with Pulumi. I figure part of that is because Pulumi isn't waiting for an API call to return, but it's actually waiting on an object to create. Internally, Pulumi knows how to resolve the dependencies, so I'm able to pass Pulumi objects to other Pulumi objects and it all works out.

.apply returns an Output<string>, if you do toString on it (fs.write) you will get issues 😞

I’ll admit that I don’t know a lot of the details about

Output< >

and

pulumi.apply

work. But my (perhaps incorrect) understanding is that you should really try to avoid relying on the state of a resource for the execution of your Pulumi program. e.g. if you want to write the

ec2VM.id

to a file or something. Because there isn’t a good way to reliably obtain that value. If you are running a

pulumi preview

(sometimes called a dry run), the resource is never created. So

ec2VM.id

never actually has a value. (And throwing a runtime error is probably better than giving you “” or undefined, or something that looks correct but isn’t.) The way

Output< >

is used internally in the Pulumi engine is to ensure that operations are sequenced correctly. e.g. if resource B requires the id of resource A, then Pulumi will wait for the first resource to be created, then read the constructed value, etc. Typically this “just works”, but in more advanced cases you’d need to do something like:

// Wait for resource A, B, C to be created.
// Then pass all their values to a lambda,
// return some Output< >
pulumi
    .all([resA, resB, resC])
    .apply( ([resAval, resBval, resCval]) => {
    return ...
});

But the above code again only works when doing a

pulumi up

. (When

resA

,

resB

, and

resC

have been created and/or are “known”.) That is my vague/hazy understanding, so as for your specifc question:

If I want to fs.write 

Output<string>

 , how I can do that?

My (again, perhaps incorrect/incomplete/wrong) understanding is: 1. You might not want to be doing that, it might be a code smell. 2. as an FYI, getting the

Output<>

won’t work in “previews” and only “updates”. 3. “something something

pulumi.all(…).apply(…)

might get you the value, but unfortunately will itself return an

Output< >

. (So you’d see it as a side-effect during the Pulumi program’s execution, but never during a preview, etc.) Hopefully that is some non-zero amount of helpful. (And maybe someone else on the team more knowledgeable can point you in a clearer direction.)

Thanks for the reply @colossal-beach-47527, not sure if I am doing smth wrong, as I said my use case: 1. create blob storage 2. create a config.xml with 2 values (blob storage, blob access key) 3. store this file inside blob storage 4. get file path and create final resource, that needs to know where is config.xml