Environment Variables and Secrets in .NET Core: Best Practices

Environment - is exactly the place, where you gonna be store such variables as connections string, different usernames for authorisations in external systems, ports, number settings and etc.

Dotnet framework provides special interface for working with env files and, also, special secured container for more sensible and secured information called user-secrets.

Adding secrets to project

dotnet user-secrets init

dotnet user-secrets set "Redis:ConnectionString" "12345"

Accessing configuration (for secrets - similar)

IConfiguration configuration;

// with get
Configuration.GetSection("Redis")

// indexed key style
Configuration["Redis:ConnectionString"]

Mapping configuration to POCO

var moviesConfig = Configuration.GetSection("Redis").Get<RedisOptions>();

Accessing configuration object through Dependency Injection

class RedisOptions {
    public string ConnectionString {get; set;}
    //...
}

// binding configuration section to runtime object
services.Configure<RedisOptions>("Redis");

// Accessing anywhere in constructor through DependencyInjection
class Controller {
    public Controller(IOptions<JwtSettingsDto> jwtOptions)
    {
        //...
    }
}

Accessing connection string

Configuration.GetConnectionString("DefaultConnectionString");