.NET Core shared configuration example

What is the reason?

New configuration system for .NET Core is really awesome. But in official stylyguides it always uses in the main ASP.NET Core app. But what if we have other apps in the solution? Or we need to share configuration settings between projects? Additional info in my blog-post.

Entity Framework Core

It's even getting worse, when we want to use Migrations from EF Core. If we don't have parameter less constructor in our DbContext, there is a need for implementing IDbContextFactory. And in this case we star to face off a problem with passing connection string to our context.

Official documentation contains an example with hard-coded connection string

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;

namespace MyProject
{
    public class BloggingContextFactory : IDbContextFactory<BloggingContext>
    {
        public BloggingContext Create()
        {
            var optionsBuilder = new DbContextOptionsBuilder<BloggingContext>();
            optionsBuilder.UseSqlite("Data Source=blog.db");

            return new BloggingContext(optionsBuilder.Options);
        }
    }
}

I don't think, that this is a flexible and right way to do this kind of fabric.

So, with the solution has been written by me, it looks in the next way

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;

namespace MyProject
{
    public class BloggingContextFactory : IDbContextFactory<BloggingContext>
    {
        public BloggingContext Create()
        {
            var configurationRoot = SettingsProvider.GetConfigurationRoot(new EnvironmentProvider());
            
            var optionsBuilder = new DbContextOptionsBuilder<BloggingContext>();
            //In my project I put "mainDb" to ConfigurationConstants class
            optionsBuilder.UseSqlite(configurationRoot.GetConnectionString("mainDb"));

            return new BloggingContext(optionsBuilder.Options);
        }
    }
}

There is the article with the alternative way for solving this problem. But I don't like it due to low flexibility of configuration settings.

Build

Install .NET Core SDK

Open folder with Configuration.sln in the shell. Then

    dotnet restore
    dotnet build

Tests

Open folder with Configuraion.Test.csproj in the shell. Then

    dotnet test