Overriding Kestrel endpoints from appsettings.json?

[Charles Chen (CharlieDigital)]

In my appsettings.json, I have Kestrel configured like so:

"Kestrel": {
    "Endpoints": {
        "Http": {
            "Url": "http://0.0.0.0:3123"
        },
        "gRPC": {
            "Url": "http://0.0.0.0:3124",
            "Protocols": "Http2"
        }
    }
},

If I try to run .WithReplicas(4), only one of the instances will successfully start as the other instances see that the port is already taken.

If I set these to http://0.0.0.0, then everything works as expected. However, when running standalone, we have other services that are dependent on these known ports.

I would have thought:

    .WithEnvironment("Kestrel__Endpoints__Http__Url", "http://0.0.0.0")
    .WithEnvironment("Kestrel__Endpoints__gRPC__Url", "http://0.0.0.0")

would override it, but I am finding that this is not the case.

I think I'm also misunderstanding the ProjectResourceOptions.ExcludeKestrelEndpoints setting as this does not seem to have an effect. Is there are better workaround for this setup?