Possibly dumb question, but does the Automation API .net version use Kestrel when running? Seeing a weird error when getting to the refresh stage where it crashes stating that kestrel cannot bind to the porta as it is already in use, which it is, by the web app I'm trying to run Pulumi from

Yeah the dotnet Automation API sets up Kestrel https://github.com/pulumi/pulumi/blob/master/sdk/dotnet/Pulumi.Automation/WorkspaceStack.cs#L661 but it should listen to an ephemeral port by setting it to 0

not a dumb question - yes it does. It spins up a GRPC host when using Automation API to run inline programs. Like @prehistoric-coat-10166 said though it should be grabbing its own port so this may be an issue

It seems to be trying to grab the same port my app is running, and if I change the port it also changes, so I am guessing some config I have in my app is overriding the pulumi one

yes, if you have

appsettings.json

it may be trying to grab that in error if it is located in the same directory. I suggest opening an issue because we should probably disable that

yeah I do have an appsettings.json specifying that port, will raise a bug

FYI the PR that should resolve this was merged earlier today