No matter how you like to participate in developer communities, Pulumi wants to meet you there. If you want to meet other Pulumi users to share use-cases and best practices, contribute code or documentation, see us at an event, or just tell a story about something cool you did with Pulumi, you are part of our community.

Pulumi Community

Right approach to creation. The ID of a Vpc is an Input, which is a union of string and IDOutput. You can use either. However, you shouldn't need to check if the resource already exists: that's Pulumi's job.

If you used Pulumi to create it originally, then Pulumi still knows about it and won't create it again. This is part of the declarative approach to resource provisioning.

If the resource was created outside of Pulumi, then instead of conditionally creating the resource, the appropriate thing to do is to unconditionally import it once, then allow Pulumi to manage the resource from then on.

Ah okay I see - yes this was my approach for cases where we have a VPC created outside of pulumi.  So conditional creation isn't a workable solution. Well thank you for the clearing that up <@U012UJTT55M>

yep, agree with tenwit here. just to clarify though, there is a way of doing this. just make the `CreateSubnet` function take `IDOutput` and then check if the vpc exists in the calling code

It's workable, but you'd need to wrap almost your entire Pulumi program in conditions. It doesn't fit the declarative model. Pulumi isn't imperative: you don't ask Pulumi to _do_ something like create a VPC. You declare something: you ask it to ensure that the the VPC exists.

some thing like:

```var vpc *vpc
if config.CreateNewVPC {
  // create a new VPC
  vpc = aws.NewVPC
} else {
  vpc = aws.LookupVPC
}

subnets = CreateSubnets(ctx, vpc.ID()```

also, you probably want to make your function ComponentResources

oh okay i better find out what that means! _googles_

<https://www.pulumi.com/docs/intro/concepts/resources/#components>