InvalidOperationException: Could not find 'UserSecretsIdAttribute' on assembly

Question

After deploying ASP.NET Core app to azure and opening the site, I get the following error:

InvalidOperationException: Could not find \'UserSecretsIdAt

Answer 1

My .NET Core 3.* Worker Service required additional setup over a Web project.

In Program.cs in the CreateHostBuilder method I needed this:

.ConfigureAppConfiguration((ctx, builder) =>
                {
                    // enable secrets in development
                    if (ctx.HostingEnvironment.IsDevelopment())
                    {
                        builder.AddUserSecrets();
                    }
                })

But (unlike my Web project) I explicitly needed to add this nuget package:

install-package Microsoft.Extensions.Configuration.UserSecrets

After that I could access the secrets.