I'm obviously doing something wrong here with my inputs and outputs, but I'm not really sure what. I'm trying to define a dynamic Resource that will check the status of a series of virtual machines. I have an interface for what a virtual machine 'looks like':

export interface IP {
  ...
  address: string;
  ...
}

export interface IVirtualMachine {
  ...
  primaryIp: IP;
  ...
}

Elsewhere I'm passing objects defined as IVirtualMachine around between ComponentResource objects, and accessing

vm.primaryIp.address

without issue, but this is the first time I've tried to use one within a dynamic provider. My resource constructor has this interface for `args`:

interface GetReadyInputs {
  clientConfiguration: pulumi.Input<ClientConfiguration>;
  nodes: pulumi.Input<IVirtualMachine[]>;
}

and the provider

async create

function expects this:

interface GetReadyProviderInputs {
  clientConfiguration: ClientConfiguration;
  nodes: IVirtualMachine[];
}

But if I try and access the properties of an

IVirtualMachine

within the provider I get errors for

Cannot read properties of undefined

. Some judicious

console.log

output tells me it's because the value of each item in the

nodes

list at that point seems to be a Pulumi string URN, not an object satisfying

IVirtualMachine

. So how am I supposed to be passing these objects around so that I can correctly access the properties of them within my provider. For what it's worth the values I'm trying to access are known at compile time, not looked up at run time, but if they could be that would be amazing and future-proof my code.

Are you returning the full objects from

check()

? Or just their URNs?

I've not actually written a custom

check()

function. All the other objects I'd passed, including ones that were nested structures, were available fully without it, so I was expecting the same to be true in this case. From your pointer I get that if I wanted my values to be resolvable at runtime I'd probably need

check()

to do a lookup to fill them in, but given that currently they're available compile-time I was expecting it to Just Work (tm).

If the object implementing IVirtualMachine is a resource it will be serialsied across the wire to the dynamic provider as a resource reference, and because dynamic providers don't support full style references it translates to just a URN.

So what's the 'correct' thing to do here? Pull out the child property I actually want and pass just that to the dynamic provider?

yeh that'll work, or write a wrapper function to just copy out all the interface fields into a new plain object

Hmm. Is my definition of the input as

pulumi.Input<IVirtualMachine[]>

correct, or should it be

pulumi.Input<IVirtualMachine>[]

? Is it an input which contains a list, or a list of inputs? I don't seem to be able to unwrap the former to get at the properties of individual

IVirtualMachine

objects, so I'm guessing I want the latter. I'm keen to get this right because it's greenfield. So anything which I get wrong/have as a bad pattern will probably end up replicated all over the place for other components and then become massively hard to unpick. Also, I know properties in Pulumi can be marked as secret so they are encrypted in state. I don't see a way to do that with dynamic providers?

inputs depends on your use case, I can't comment to what's correct there. But where ever the input layer is you can unwrap and change it to something else via an output.apply. dynamic providers don't currently support secrets, we're looking at whole new provider sdks to replace them probably but just not had the time to push those over the line to finished yet