无法读取 dotnet 核心中链接的 appsettings.json 文件中的值

Question

In an aspnetcore 2.0 project I'm trying to setup a single, shared appsettings.json file throughout my web application and several of my xunit test projects.

First off, everything works fine when I add the appsettings.json "regularly" to my projects individually. However, when I attempt to add a single reference/linked file from a different path, the values aren't read out during runtime.

To set this up, for each project I add the linked file to the .csproj:

<ItemGroup>
    <Content Include="..\Shared\appsettings.json">
        <Link>appsettings.json</Link>
        <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </Content>
</ItemGroup>

And on each build, I can verify it is output nicely to the /bin/Debug/netcoreapp2.0 directory:

The problem is that when reading it out, either through the default Startup of my webapi or in the tests, the settings values are always null. I'm using a strong typed configuration. In the webapi project, I'm using the WebHost.CreateDefaultBuilder() with the aspnetcore 2.0 conventions (which under the hood looks at hostingEnvironment.EnvironmentName , dotPeek tells me).

But also in the case of the test projects, the same occurs. Which all can be explained by the following example in my global test fixture:

var builder = new ConfigurationBuilder()
    // .SetBasePath(???)
    .AddJsonFile("appsettings.json");

var configuration = builder.Build();

var settings = new FooSettings();
configuration.GetSection("FooSettings").Bind(settings);

if (settings == null) throw new Exception("Could not find or parse 'appsettings.json'");

// The problem: always fails on this check
if (string.IsNullOrEmpty(settings.Bar)) throw new Exception("Could not find or parse 'FooSettings'");

The problem is commented on the last line in the above sample. Again, it works perfect when I directly add the appsettings.json file to the project root, instead of adding it as a linked reference to a shared folder. I am assuming I have to either change the .csproj configuration differently OR use a different .SetBasePath(???) . But for both I'm struggling on how to achieve it.

The question: What can I do to make the linked appsettings file to be read properly in all my projects?

NB I found several other posts, but couldn't find any with a matching answer, specifically for dotnetcore.

Answer 1

It started working after i added some code in Program (thanks @mr_squall for direction..):

     public static void Main(string[] args)
        {
            CreateHostBuilder(args)
#if !DEBUG
                .UseContentRoot(Path.GetDirectoryName(Assembly.GetEntryAssembly().Location))
#endif
                .Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureAppConfiguration((hostingContext, config) =>
                {
                    config.SetBasePath(Path.GetDirectoryName(Assembly.GetEntryAssembly().Location));
                })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                });