You can read more about them at https://pulumi.io/reference/programming-model.html#overview.

I’m confused … in that I use pulumi to deploy my app which e.g. has a defined ingress. Who would I export these values to? What would consume them?

Or is this just an export, like any other ts module and you have to write ts code to consume them?

The reason I ask is because tutorials have code like:

// Export the Deployment name
export const deploymentName = deployment.metadata.apply(m => m.name);

and the comment isn’t helpful. I can see it is an export, but will pulumi fail without it? or is it simply to expose internals for reuse with my potential other code?

When I remove the exports, it seems I have

3 unchanged

resources, so it appears these exports are typical ts module exports for reuse. Unless I’m wrong, I’d suggest a change to the doc code - exports are only needed if they are reused. In this case it looks like they are not (which led to my confusion)

Ohhh, I think I get it now. They will be displayed - so it’s an informational thing?

They're either A) informational for the you the end user or B) informational for other Pulumi applications.

You're able to reference other stacks via

StackReference

so you can break apart your infrastructure into different "deployable units" and manage them independently.

A good example is you might have a VPC stack that publishes it's VPC and Subnet IDs and then another application stack that consumes those to deploy VMs or other resources into that VPC and Subnets.

More on that is at https://pulumi.io/reference/organizing-stacks-projects.html#inter-stack-dependencies.