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dotnet not loading appsettings.json if executing dotnet outside publish folder – Nginx

I’ve been hovering around this issue for quite some time now and still haven’t found an answer, nor another post dealing with the same problem.

I have published a .net 5.0 Website and everything works fine if I run dotnet inside the same published folder. in this folder I also have a file called appsettings.json with all the configuration needed by the application ie:

+ path
 + to
   + karinapi
     - MinosIT.Karin.API.dll
     - appsettings.json

When I run dotnet inside the folder, everything works fine and the settings are read without any problem:

cd /path/to/karinapi
dotnet MinosIT.Karin.API.dll

The result is ok ie:

user@machine$ dotnet MinosIT.Karin.API.dll
info: MinosIT.Karin.API.Program[0]
      Inicializando migración
info: MinosIT.Karin.Migrations.HDIKarinMigrations[0]
      Verificando migraci+on
info: MinosIT.Karin.Migrations.HDIKarinMigrations[0]
      Checking whether journal table exists..
info: MinosIT.Karin.Migrations.HDIKarinMigrations[0]
      Fetching list of already executed scripts.
info: MinosIT.Karin.API.Program[0]
      finalizando migración

but when I try to follow this guide:
https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/linux-nginx?view=aspnetcore-5.0
it says that you have to create a service and run the app like this

/usr/bin/dotnet /path/to/karinapi/MinosIT.Karin.API.dll

The problem is that when I try to run my app while being outside the publish folder, dotnet doesn’t seem to find appsettings.json file ie:

user@mymachine$ pwd
/path/to/
user@mymachine$ /user/bin/dotnet /path/to/karinapi/MinosIT.Karin.API.dll

Application fails and throws this error:

 user@mymachine$ dotnet karinapi/MinosIT.Karin.API.dll

Unhandled exception. System.ArgumentNullException: Value cannot be null. (Parameter ‘implementationInstance’)

at Microsoft.Extensions.DependencyInjection.ServiceCollectionServiceExtensions.AddSingleton[TService](IServiceCollection services, TService implementationInstance)
at MinosIT.Karin.API.Startup.ConfigureServices(IServiceCollection services) in D:Minos ITKarinMinosIT.KarinBackEndMinosIT.Karin.apiStartup.cs:line 72
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) in /_/src/coreclr/src/System.Private.CoreLib/src/System/Reflection/RuntimeMethodInfo.cs:line 399
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.InvokeCore(Object instance, IServiceCollection services)
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.<>c__DisplayClass9_0.g__Startup|0(IServiceCollection serviceCollection)
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.Invoke(Object instance, IServiceCollection services)
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.<>c__DisplayClass8_0.b__0(IServiceCollection services)
at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.UseStartup(Type startupType, HostBuilderContext context, IServiceCollection services, Object instance)
at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.<>c__DisplayClass13_0.b__0(HostBuilderContext context, IServiceCollection services)
at Microsoft.Extensions.Hosting.HostBuilder.CreateServiceProvider()
at Microsoft.Extensions.Hosting.HostBuilder.Build()

I’m using Microsoft.Extensions.Configuration.

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

    public IConfiguration Configuration { get; }
    ...

    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

and inside StartUp.ConfigureServices I’m using:

var connectionString = Configuration.GetConnectionString("ConnectionStringName");
var section = Configuration.GetSection("CustomSection").Get<CustomConfiguration>();

When I debug, my code via logging I understand that the problem might be the ASP.NET Core doesn’t know where to read appsettings.json, I have looked at dotnet cli docs, environment variables, other configuration types and I can’t seem to find the problem. I really don’t know what else to look for, any guidance or help will be appreciated.

Thanks in advance for your help.

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Found a solution, I'm posting here in case someone else is struggling with the same error:

    inside Program.cs I changed from:

            public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                }
                );

    to

            public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
                .ConfigureAppConfiguration((context, config) =>
                {
                    var assembly = Assembly.GetExecutingAssembly();
                    var currentPath = System.IO.Path.GetDirectoryName(assembly.Location);

                    config.SetBasePath(currentPath);
                    config.AddJsonFile("appsettings.json", optional: false, reloadOnChange: false);
                })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                }
                );

  2. 0

    Similar to your approach, a more concise expression would be to use AppContext.BaseDirectory.

    I found a good resource which describes many ways at getting the "current" directory: 6 ways to get the current directory in C#

        public static IHostBuilder CreateHostBuilder(string[] args) =>
    Host.CreateDefaultBuilder(args)
            .ConfigureAppConfiguration((context, config) =>
            {
                config.SetBasePath(AppContext.BaseDirectory);
                config.AddJsonFile("appsettings.json", optional: false, reloadOnChange: false);
            })
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            }
            );
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