[lindydonna]

(I'm a product manager at Pulumi.)

> That makes it sound like Pulumi only runs the infrastructure declarations when you run "pulumi update", and that those things don't run when your program runs. That's confusing to me, because your examples (like the thumbnailer) seems to have the program and the declarations in the same file.

This is an optional way to do it, by combining the runtime code and infra code. The runtime code doesn't run when you deploy with "pulumi update," but it is packaged and sent to AWS.

You can also put the runtime code in a different file, as in this example: https://github.com/lindydonna/velocity-examples/tree/master/...

> Is Pulumi stateful, then? If you create resources with "pulumi update", change the declarations without updating, and run "pulumi destroy" or whatever, it will only delete the stuff you created in the first step? (That is what I would expect. I would also expect it to support a dry run mode with a diff showing what operations would be executed.) If so, where is this state stored?

Yes, the state is stored on pulumi.com. The state is list of resource IDs that you provisioned. The Pulumi CLI does indeed have a dry run mode that shows a diff: whenever you run "pulumi update", it first shows a preview.

[eikenberry]

Is there an option for self-hosting your state files vs relying on pulumi.com?

[spooneybarger]

You could self-host if you want. The default is relying on pulumi.com

[zard784]

Does it understand how to mutate resources in-place with out a downtime? Or is that code/logic something I need to write and track like I do today?

[lindydonna]

(Disclosure: I work at Pulumi)

Yes, Pulumi does mutate resources in place, if the cloud provider supports it. For most resources, it will create a new one (such as a new ECS task), and wait for it to be ready before deleting the old one.