libfoo-loading.cs

using System;
using System.IO;
using System.Reflection;
using System.Runtime.InteropServices;
public class YourLibrary
{
    private static bool? s_isAmazon;

    // static constructor
    static YourLibrary () =>
        NativeLibrary.SetDllImportResolver(typeof(YourLibrary).Assembly, MyNativeLibraryLoaderForLibFoo);

     private static IntPtr MyNativeLibraryLoaderForLibFoo (string libraryName, Assembly assembly, DllImportSearchPath? searchPath)
     {
        if (!OperatingSystem.IsLinux() || libraryName != "libFoo.so")
            return IntPtr.Zero; // continue with default runtime native library loader

        if (s_isAmazon == null)
        {
            s_isAmazon = RuntimeInformation.OSDescription.Contains("amazon", StringComparison.OrdinalIgnoreCase);
            if (s_isAmazon == false)
            {
                // check release files as well
                string filename = File.Exists("/etc/os-release") ? "/etc/os-release" : File.Exists("/etc/release") ? "/etc/release" : null;
                if (filename is not null)
                {
                    try
                    {
                        s_isAmazon = File.ReadAllText(filename).Contains("amazon", StringComparison.OrdinalIgnoreCase);
                    }
                    catch (IOException)
                    {
                        // ignore
                    }
                }
            }
        }

        if (s_isAmazon == true)
        {
            NativeLibrary.TryLoad("libFoo_amazon.so", out IntPtr lib);
            return lib;
        }

         // other distros?

        return IntPtr.Zero;
    }
}