AppHost project crashes on startup: System.UriFormatException: Invalid URI: The hostname could not be parsed.

[SapiensAnatis]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Hey, just trying to integrate Aspire into my existing solution. The first time I tried it, it threw this on startup:

System.UriFormatException: Invalid URI: The hostname could not be parsed.

I eventually narrowed this down to using an applicationUrl of "http://*:80" in my web API's launchSettings.json. I had this set to listen on all IP addresses as I need to connect to my web API from my smartphone.

Expected Behavior

This is my first time using Aspire so I don't have the context to know why it reads launchSettings, but perhaps these URLs could be skipped. I think in any case the error message could be improved, as I only narrowed it to launchSettings by checking the Aspire source code.

Steps To Reproduce

1. Create new Web API project
2. Set applicationUrl to http://*:80 in the web API's launchSettings.json:

{
    "$schema": "https://json.schemastore.org/launchsettings.json",
    "profiles": {
        "DragaliaAPI": {
            "commandName": "Project",
            "environmentVariables": {
                "ASPNETCORE_ENVIRONMENT": "Development",
            },
            "applicationUrl": "http://*:80"
        }
    }
}

3. Create new Aspire app host with this configuration:

var builder = DistributedApplication.CreateBuilder(args);

builder.AddProject<Projects.DragaliaAPI>("dragaliaapi");

builder.Build().Run();

4. Crash

Exceptions (if any)

Unhandled exception. System.UriFormatException: Invalid URI: The hostname could not be parsed.
   at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind, UriCreationOptions& creationOptions)
   at System.Uri..ctor(String uriString)
   at Aspire.Hosting.ProjectResourceBuilderExtensions.WithProjectDefaults(IResourceBuilder`1 builder, ProjectResourceOptions options) in /_/src/Aspire.Hosting/ProjectResourceBuilderExtensions.cs:line 407
   at Aspire.Hosting.ProjectResourceBuilderExtensions.AddProject[TProject](IDistributedApplicationBuilder builder, String name, Action`1 configure) in /_/src/Aspire.Hosting/ProjectResourceBuilderExtensions.cs:line 216
   at Aspire.Hosting.ProjectResourceBuilderExtensions.AddProject[TProject](IDistributedApplicationBuilder builder, String name) in /_/src/Aspire.Hosting/ProjectResourceBuilderExtensions.cs:line 63
   at Program.<Main>$(String[] args) in C:\Users\jay0\Projects\Dawnshard\AppHost\Program.cs:line 3

.NET Version info

.NET SDK:
 Version:           8.0.401
 Commit:            811edcc344
 Workload version:  8.0.400-manifests.57f7c351
 MSBuild version:   17.11.4+37eb419ad

Anything else?

Aspire.Hosting.AppHost v8.2.0.

[davidfowl]

http://*:80 looks to be the problem.