Secure ASP.NET Core Health Checks to a specific port

To secure Health Checks it is possible to make them available on internal addresses only and on a different port to the publicly served pagesAPI endpoints. First we need to make the service available over 2 different ports, this can be achieved by adding a Urls value to the appsettings.config. json "Logging": \\\{ "IncludeScopes": false, "LogLevel": \{ "Default": "Debug", "System": "Information", "Microsoft": "Information" \\} }, "Urls": "http:/localhost:1114;http:/localhost:1115", "ManagementPort": "1115", "ConnectionStrings": \\{ "LoginServiceDb": "Data Source=.,11433;Initial Catalog=LoginServiceDatabase;Integrated Security=true;" \}, This can be done in several ways, and is described in more detail by Andrew Lock in his post 5 ways to set the URLs for an ASP.NET Core app. Now when you debug the service you should see in the log that it is listening on 2 ports ``` info: Microsoft.Hosting.Lifetime[0] Now listening on: http:/localhost:1114 info: Microsoft.Hosting.Lifetime[0] Now listening on: http:/localhost:1115 info: Microsoft.Hosting.Lifetime[0] Application started. Press Ctrl+C to shut down.

**Special note if you are using http.sys** If you want to run this over https you will need to take care of the port reservation and certification binding. I have a explanation of that in the GitHub Repo README.
:::  Now that we have the service listening on 2 addresses we can specify one of them will serve up the Health Checks by setting the `ManagementPort`.  In `startup.cs` we can use the `ManagementPort` to secure the Health Check endpoint  ```csharp  HealthCheck middleware  app.UseHealthChecks("hc", $"\\{Configuration["ManagementPort"]\}", new HealthCheckOptions() \\{  Predicate = _ => true,  ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse  \});  app.UseEndpoints(endpoints => \\\{  endpoints.MapControllerRoute("default", "\{controller=Home\\}\{action=Index\}\\{id?\}");  endpoints.MapHealthChecks("health").RequireHost($"*:\\{Configuration["ManagementPort"]\}");  });
```  If you debug now you will have access to the `health` endpoint only on the `ManagementPort` and not on the public facing URL.  ![HealthCheck external shows 404 while internal shows overall health status](/img/health_endpoint.png) More interestingly you can also go to the `hc` endpoint, this contains more detailed information about the state of the service and therefore needs to be secured.  ![HealthCheck external shows 404 while internal shows detailed health status](/img/hc_endpoint.png) Now you can safely get the status of your services reported as json, but there are 2 further aspects of ASP.NET Core Health Checks, the UI and push-based monitoring, i will cover those in parts 2 and 3.