Environment variables not being used when debugging through a Service Fabric project

Question

When creating an ASP.NET Core app an environment variable called ASPNETCORE_ENVIRONMENT=Development will be set for you and when debugging you will see that the

Answer 1

The answer from Duncan worked for me, but there is a small variation for me, maybe due to the version of ASP.NET Core and Service Fabric I use.

I need to override the method CreateServiceInstanceListeners in my Web Stateless Service. So that means I'll have this code:

protected override IEnumerable CreateServiceInstanceListeners()
{
    return new ServiceInstanceListener[]
    {
        new ServiceInstanceListener(serviceContext =>
            new WebListenerCommunicationListener(serviceContext, "ServiceEndpoint", (url, listener) =>
            {
                ServiceEventSource.Current.ServiceMessage(serviceContext, $"Starting WebListener on {url}");

                var environment = FabricRuntime.GetActivationContext()
                    ?.GetConfigurationPackageObject("Config")
                    ?.Settings.Sections["Environment"]
                    ?.Parameters["ASPNETCORE_ENVIRONMENT"]?.Value;

                return new WebHostBuilder().UseWebListener()
                    .ConfigureServices(
                        services => services
                            .AddSingleton(serviceContext))
                    .UseContentRoot(Directory.GetCurrentDirectory())
                    .UseStartup()
                    .UseEnvironment(environment)
                    .UseApplicationInsights()
                    .UseUrls(url)
                    .Build();
            }))
    };
}

Of course, you need to set the ASPNETCORE_ENVIRONMENT variable as explained by Duncan.