Clean up sys.json

Connected.Host.sln

@@ -5,26 +5,6 @@ VisualStudioVersion = 17.3.32901.215
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.Host", "src\Connected.Host\Connected.Host.csproj", "{A2A01D43-0CEE-4E49-8EC1-F16CA92F3C30}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Dependencies", "Dependencies", "{D875F828-05A0-4A52-9A36-6F5B0370171D}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.Data", "..\Connected.Framework\src\Connected.Data\Connected.Data.csproj", "{67532F27-3F13-404D-AD65-34317719059D}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Common.Types", "..\Connected.Common.Types\src\Connected.Common.Types\Connected.Common.Types.csproj", "{216E4481-92B6-4E52-8877-3C6D547803ED}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.Rest", "..\Connected.Framework\src\Connected.Rest\Connected.Rest.csproj", "{AD931DF4-9695-4D9A-8E08-8A5041175755}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.Entities", "..\Connected.Framework\src\Connected.Entities\Connected.Entities.csproj", "{DB941857-07B7-4CD0-B43F-32EC51B5F195}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.Expressions", "..\Connected.Framework\src\Connected.Expressions\Connected.Expressions.csproj", "{6FCD7B5E-A42C-433A-8C2E-5BA412736F99}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.Interop", "..\Connected.Framework\src\Connected.Interop\Connected.Interop.csproj", "{84D0EAE0-724F-421A-BDA2-5DEC2D9A254C}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.ServiceModel.Client.Data", "..\Connected.Framework.ServiceModel.Client\src\Connected.ServiceModel.Client.Data\Connected.ServiceModel.Client.Data.csproj", "{EBBECB6F-C996-41C4-B05A-39309A03839E}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connected.Instance", "..\Connected.Framework\src\Connected.Instance\Connected.Instance.csproj", "{5312A990-8797-44E2-9BA9-858D51DE3825}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Common.Notes", "..\Connected.Common\src\Connected.Common.Notes\Connected.Common.Notes.csproj", "{28F99091-B4CB-43BF-A6DF-4D47621420D0}"
-EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -35,57 +15,10 @@ Global
 		{A2A01D43-0CEE-4E49-8EC1-F16CA92F3C30}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{A2A01D43-0CEE-4E49-8EC1-F16CA92F3C30}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{A2A01D43-0CEE-4E49-8EC1-F16CA92F3C30}.Release|Any CPU.Build.0 = Release|Any CPU
-		{67532F27-3F13-404D-AD65-34317719059D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{67532F27-3F13-404D-AD65-34317719059D}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{67532F27-3F13-404D-AD65-34317719059D}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{67532F27-3F13-404D-AD65-34317719059D}.Release|Any CPU.Build.0 = Release|Any CPU
-		{216E4481-92B6-4E52-8877-3C6D547803ED}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{216E4481-92B6-4E52-8877-3C6D547803ED}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{216E4481-92B6-4E52-8877-3C6D547803ED}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{216E4481-92B6-4E52-8877-3C6D547803ED}.Release|Any CPU.Build.0 = Release|Any CPU
-		{AD931DF4-9695-4D9A-8E08-8A5041175755}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{AD931DF4-9695-4D9A-8E08-8A5041175755}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{AD931DF4-9695-4D9A-8E08-8A5041175755}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{AD931DF4-9695-4D9A-8E08-8A5041175755}.Release|Any CPU.Build.0 = Release|Any CPU
-		{DB941857-07B7-4CD0-B43F-32EC51B5F195}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{DB941857-07B7-4CD0-B43F-32EC51B5F195}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{DB941857-07B7-4CD0-B43F-32EC51B5F195}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{DB941857-07B7-4CD0-B43F-32EC51B5F195}.Release|Any CPU.Build.0 = Release|Any CPU
-		{6FCD7B5E-A42C-433A-8C2E-5BA412736F99}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{6FCD7B5E-A42C-433A-8C2E-5BA412736F99}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{6FCD7B5E-A42C-433A-8C2E-5BA412736F99}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{6FCD7B5E-A42C-433A-8C2E-5BA412736F99}.Release|Any CPU.Build.0 = Release|Any CPU
-		{84D0EAE0-724F-421A-BDA2-5DEC2D9A254C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{84D0EAE0-724F-421A-BDA2-5DEC2D9A254C}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{84D0EAE0-724F-421A-BDA2-5DEC2D9A254C}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{84D0EAE0-724F-421A-BDA2-5DEC2D9A254C}.Release|Any CPU.Build.0 = Release|Any CPU
-		{EBBECB6F-C996-41C4-B05A-39309A03839E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{EBBECB6F-C996-41C4-B05A-39309A03839E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{EBBECB6F-C996-41C4-B05A-39309A03839E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{EBBECB6F-C996-41C4-B05A-39309A03839E}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5312A990-8797-44E2-9BA9-858D51DE3825}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5312A990-8797-44E2-9BA9-858D51DE3825}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5312A990-8797-44E2-9BA9-858D51DE3825}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5312A990-8797-44E2-9BA9-858D51DE3825}.Release|Any CPU.Build.0 = Release|Any CPU
-		{28F99091-B4CB-43BF-A6DF-4D47621420D0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{28F99091-B4CB-43BF-A6DF-4D47621420D0}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{28F99091-B4CB-43BF-A6DF-4D47621420D0}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{28F99091-B4CB-43BF-A6DF-4D47621420D0}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
-	GlobalSection(NestedProjects) = preSolution
-		{67532F27-3F13-404D-AD65-34317719059D} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{216E4481-92B6-4E52-8877-3C6D547803ED} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{AD931DF4-9695-4D9A-8E08-8A5041175755} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{DB941857-07B7-4CD0-B43F-32EC51B5F195} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{6FCD7B5E-A42C-433A-8C2E-5BA412736F99} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{84D0EAE0-724F-421A-BDA2-5DEC2D9A254C} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{EBBECB6F-C996-41C4-B05A-39309A03839E} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{5312A990-8797-44E2-9BA9-858D51DE3825} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-		{28F99091-B4CB-43BF-A6DF-4D47621420D0} = {D875F828-05A0-4A52-9A36-6F5B0370171D}
-	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {8E8D9F6F-68E1-466C-8D83-5ECB3AA3FC76}
 	EndGlobalSection

src/Connected.Host/Configuration/SysConfiguration.cs

@@ -1,49 +1,14 @@
-namespace Connected.Host.Configuration
+namespace Connected.Host.Configuration;
+
+internal class SysConfiguration
 {
-	internal static class SysConfiguration
-	{
 	private const string DefaultStart = "Connected.Instance.Start, Connected.Instance";
 
-		private static List<MicroServiceDescriptor> _microServices;
+	private string _start = DefaultStart;
-		private static List<string> _locations;
-		private static string _start;
-		public static List<MicroServiceDescriptor> MicroServices => _microServices;
-		public static List<string> Locations => _locations;
-		public static string Start => _start;
-		public static void Build()
-		{
-			var cb = new ConfigurationBuilder();
-			var appPath = AppContext.BaseDirectory;
-			var segments = new Uri(appPath).Segments;
 
-			segments = segments.Select(e => e.Replace("%20", " ")).ToArray();
+	public List<MicroServiceDescriptor> MicroServices { get; set; } = new();
 
-			for (var i = 1; i <= segments.Length; i++)
+	public List<string> Repositories { get; set; } = new();
-			{
-				var pathBase = Path.Combine(segments[0..i]);
-				var filePath = Path.Combine(pathBase, "sys.json");
 
-				if (File.Exists(filePath))
+	public string Start { get => _start ?? DefaultStart; set => _start = value; }
-				{
-					cb.AddJsonFile(filePath, true, false);
-					break;
-				}
-			}
-
-			cb.AddEnvironmentVariables();
-
-			var config = cb.Build();
-
-			_microServices = new List<MicroServiceDescriptor>();
-			_locations = new List<string>();
-
-			config.Bind("microServices", _microServices);
-			config.Bind("locations", _locations);
-
-			_start = config["start"];
-
-			if (string.IsNullOrWhiteSpace(_start))
-				_start = DefaultStart;
-		}
-	}
 }

src/Connected.Host/Connected.Host.csproj

@@ -7,6 +7,9 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyModel" Version="7.0.0" />
+    <PackageReference Include="NuGet.PackageManagement" Version="6.4.0" />
+    <PackageReference Include="NuGet.Protocol" Version="6.4.0" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.2.3" />
     <PackageReference Include="Microsoft.Data.SqlClient" Version="5.0.0" />
     <PackageReference Include="Microsoft.SqlServer.Management.SqlParser" Version="160.22515.0" />

src/Connected.Host/ConnectedPlatformService.cs

@@ -0,0 +1,32 @@
+using System.Reflection;
+using Connected.Host.Configuration;
+using Microsoft.Extensions.Options;
+
+namespace Connected.Host;
+
+internal sealed class ConnectedPlatformService : BackgroundService
+{
+	private SysConfiguration Config { get; }
+	private IConfiguration GlobalConfig { get; }
+	public ConnectedPlatformService(IOptions<SysConfiguration> config, IConfiguration globalConfig)
+	{
+		Config = config.Value;
+		GlobalConfig = globalConfig;
+	}
+
+	protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+	{
+		await DependencyLoader.LoadPackages(Config.MicroServices, Config.Repositories);
+
+		if (Type.GetType(Config.Start) is not Type startupType)
+			throw new Exception($"Cannot resolve startup type. ({Config.Start}).");
+
+		if (startupType.GetMethod("ConfigureAsync", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic) is not MethodInfo configureMethod)
+			throw new Exception($"ConfigureAsync does not exists in the startup type {startupType}. Startup must have static 'async Task ConfigureAsync(params string[] args)' method.");
+
+		if (configureMethod.Invoke(null, new object[] { GlobalConfig }) is not Task task)
+			throw new Exception($"ConfigureAsync of type {startupType} must return Task.");
+
+		await task;
+	}
+}

src/Connected.Host/DependencyLoader.cs

@@ -0,0 +1,343 @@
+using System.Reflection;
+using System.Runtime.Versioning;
+using Connected.Host.Configuration;
+using Microsoft.Extensions.DependencyModel;
+using NuGet.Configuration;
+using NuGet.Frameworks;
+using NuGet.Packaging;
+using NuGet.Packaging.Core;
+using NuGet.Packaging.Signing;
+using NuGet.Protocol.Core.Types;
+using NuGet.Resolver;
+using NuGet.Versioning;
+
+
+namespace Connected.Host;
+
+public class DependencyLoader
+{
+	/// <summary>
+	/// Loads packages from the specified repositories into memory.
+	/// </summary>
+	/// <param name="packages">A list of package Id and version descriptors to load.</param>
+	/// <param name="repositoryLocations">A list of NuGet repositories to check.</param>
+	/// <param name="cancellationToken"></param>
+	/// <exception cref="InvalidOperationException">Thrown when a package identity could not be resolved.</exception>
+	private async Task Load(IEnumerable<MicroServiceDescriptor> packages, IEnumerable<string> repositoryLocations, CancellationToken? cancellationToken = null)
+	{
+		cancellationToken ??= CancellationToken.None;
+
+		//TODO: Wire up actual logger
+		var logger = new NuGet.Common.NullLogger();
+
+		/*
+		 * Define a source provider with specified sources.
+		 */
+		var packageSources = GetPackageSources(repositoryLocations);
+		/*
+		 * Define a package source provider with empty settings with the specified package sources.
+		 */
+		var packageSourceProvider = new PackageSourceProvider(Settings.LoadMachineWideSettings(Settings.DefaultSettingsFileName), packageSources);
+		/*
+		 * Define a repository provider with our package source and the latest API capabilities.
+		 */
+		var repositoryProvider = new SourceRepositoryProvider(packageSourceProvider, Repository.Provider.GetCoreV3());
+		/*
+		 * Setup contexts for dependency resolution and package downloading.
+		 * First, the disposable cache
+		 */
+		using var sourceCacheContext = new SourceCacheContext();
+		/*
+		 * Next, the compatible framework versions.
+		 */
+		var version = Assembly.GetExecutingAssembly()
+						.GetCustomAttributes(typeof(TargetFrameworkAttribute), false)
+						.SingleOrDefault() as TargetFrameworkAttribute;
+
+		var targetFramework = NuGetFramework.ParseFrameworkName(version.FrameworkName, DefaultFrameworkNameProvider.Instance);
+		/*
+		 * Complete list of all touched packages, to be filled out by installer and downloader.
+		 */
+		var allPackages = new HashSet<SourcePackageDependencyInfo>();
+		/*
+		 * Default dependency context.
+		 */
+		var dependencyContext = DependencyContext.Default;
+		/*
+		 * Extract list of repositories.
+		 */
+		var repositories = repositoryProvider.GetRepositories();
+		/*
+		 * Get all package identities and packages.
+		 */
+		foreach (var dependency in packages)
+		{
+			var packageIdentity = await GetPackageIdentity(dependency, sourceCacheContext, logger, repositories, cancellationToken.Value);
+
+			if (packageIdentity is null)
+				throw new InvalidOperationException($"Cannot find package {dependency.Name}.");
+
+			await GetPackageDependencies(packageIdentity, sourceCacheContext, targetFramework, logger, repositories, dependencyContext, allPackages, cancellationToken.Value);
+		}
+
+		var packagesToInstall = GetPackagesToInstall(repositoryProvider, logger, packages, allPackages);
+		/*
+		 * Install packages in standard location.
+		 */
+		var packageDirectory = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!, ".packages");
+
+		var nugetSettings = Settings.LoadDefaultSettings(packageDirectory);
+
+		await InstallPackages(sourceCacheContext, logger, packagesToInstall, packageDirectory, nugetSettings, cancellationToken.Value);
+	}
+	/// <summary>
+	/// Installs the list of packages and loads them into memory.
+	/// </summary>
+	/// <param name="sourceCacheContext">The shared context for resolved packages.</param>
+	/// <param name="logger">A standard NuGet logger.</param>
+	/// <param name="packagesToInstall">A list of packages to install.</param>
+	/// <param name="rootPackagesDirectory">The root directory into which the packages are downloaded and extracted.</param>
+	/// <param name="nugetSettings">A set of NuGet settings, containing local repos and download behavior settings.</param>
+	/// <param name="cancellationToken"></param>
+	private async Task InstallPackages(SourceCacheContext sourceCacheContext, NuGet.Common.ILogger logger,
+									   IEnumerable<SourcePackageDependencyInfo> packagesToInstall, string rootPackagesDirectory,
+									   ISettings nugetSettings, CancellationToken cancellationToken)
+	{
+		var packagePathResolver = new PackagePathResolver(rootPackagesDirectory, true);
+		var packageExtractionContext = new PackageExtractionContext(
+			PackageSaveMode.Defaultv3,
+			XmlDocFileSaveMode.Skip,
+			ClientPolicyContext.GetClientPolicy(nugetSettings, logger),
+			logger);
+
+		foreach (var package in packagesToInstall)
+		{
+			var downloadResource = await package.Source.GetResourceAsync<DownloadResource>(cancellationToken);
+
+			/*
+			 * Download package (from online, local or shared cache).
+			 */
+			var downloadResult = await downloadResource.GetDownloadResourceResultAsync(
+				package,
+				new PackageDownloadContext(sourceCacheContext),
+				SettingsUtility.GetGlobalPackagesFolder(nugetSettings),
+				logger,
+				cancellationToken);
+
+			/*
+			 * Extract package.
+			 */
+			var extractedFiles = await PackageExtractor.ExtractPackageAsync(
+				downloadResult.PackageSource,
+				downloadResult.PackageStream,
+				packagePathResolver,
+				packageExtractionContext,
+				cancellationToken);
+
+			/*
+			 * Install applicable dlls.
+			 */
+			foreach (var assembly in extractedFiles.Where(e => e.EndsWith(".dll")))
+			{
+				try
+				{
+					Assembly.LoadFrom(assembly);
+				}
+				catch (Exception e)
+				{
+					logger.LogWarning($"Could not load assembly. {e}");
+				}
+			}
+		}
+	}
+
+	/// <summary>
+	/// Generates a list of package sources from a list of repository urls.
+	/// </summary>
+	/// <param name="sources">A list of URIs of specified sources.</param>
+	/// <returns>A list of package sources for the specified NuGet repository URIs.</returns>
+	private IEnumerable<PackageSource> GetPackageSources(IEnumerable<string> sources)
+	{
+		foreach (var source in sources)
+			yield return new PackageSource(source);
+	}
+
+	/// <summary>
+	/// Returns a list of missing packages to satisfy all dependencies.
+	/// </summary>
+	/// <param name="sourceRepositoryProvider">A source repository provider for all resources to load packages from.</param>
+	/// <param name="logger">A standard NuGet logger.</param>
+	/// <param name="packages">A list of packages for which to resolve all dependencies.</param>
+	/// <param name="availablePackages">A list of available packages to resolve from.</param>
+	/// <returns></returns>
+	private IEnumerable<SourcePackageDependencyInfo> GetPackagesToInstall(SourceRepositoryProvider sourceRepositoryProvider, NuGet.Common.ILogger logger, IEnumerable<MicroServiceDescriptor> packages, HashSet<SourcePackageDependencyInfo> availablePackages)
+	{
+		/*
+		 * Create resolver to resolve missing packages
+		 */
+		var resolverContext = new PackageResolverContext(
+			   DependencyBehavior.Lowest,
+			   packages.Select(x => x.Name),
+			   Enumerable.Empty<string>(),
+			   Enumerable.Empty<PackageReference>(),
+			   Enumerable.Empty<PackageIdentity>(),
+			   availablePackages,
+			   sourceRepositoryProvider.GetRepositories().Select(s => s.PackageSource),
+			   logger);
+
+		var packagesToInstall = new PackageResolver()
+			.Resolve(resolverContext, CancellationToken.None)
+			.Select(p => availablePackages.Single(x => PackageIdentityComparer.Default.Equals(x, p)));
+
+		return packagesToInstall;
+	}
+	/// <summary>
+	/// Resolves a package identity from the supplied Id and version.
+	/// </summary>
+	/// <param name="microserviceDescriptor">The version and id of the required package.</param>
+	/// <param name="cache">The shared cache in which resolved packages are stored.</param>
+	/// <param name="nugetLogger">A standard NuGet logger.</param>
+	/// <param name="repositories">A list of repositories to check when resolving the package version.</param>
+	/// <param name="cancelToken"></param>
+	/// <returns>Returns the resolved package identity or null if it could not be resolved.</returns>
+	/// <exception cref="InvalidOperationException">Thrown when the version range could not be parsed.</exception>
+	private async Task<PackageIdentity?> GetPackageIdentity(MicroServiceDescriptor microserviceDescriptor, SourceCacheContext cache, NuGet.Common.ILogger nugetLogger, IEnumerable<SourceRepository> repositories, CancellationToken cancelToken)
+	{
+		/*
+		 * Go through repositories in order. 
+		 */
+		foreach (var sourceRepository in repositories)
+		{
+			/*
+			 * Get resource, available versions and attempt to resolve the appropriate version. If none is available, take the last one.
+			 */
+			var findPackageResource = await sourceRepository.GetResourceAsync<FindPackageByIdResource>();
+
+			var availableVersions = await findPackageResource.GetAllVersionsAsync(microserviceDescriptor.Name, cache, nugetLogger, cancelToken);
+
+			NuGetVersion selected;
+
+			if (microserviceDescriptor.Version is not null)
+			{
+				if (!VersionRange.TryParse(microserviceDescriptor.Version, out var range))
+					throw new InvalidOperationException("Invalid version range provided.");
+
+				var bestVersion = range.FindBestMatch(availableVersions);
+
+				selected = bestVersion;
+			}
+			else
+				selected = availableVersions.LastOrDefault();
+
+			if (selected is not null)
+				return new PackageIdentity(microserviceDescriptor.Name, selected);
+		}
+
+		return null;
+	}
+	/// <summary>
+	/// Searches the package dependency graph for the chain of all packages to install.
+	/// </summary>
+	private async Task GetPackageDependencies(PackageIdentity package,
+											  SourceCacheContext cacheContext,
+											  NuGetFramework framework,
+											  NuGet.Common.ILogger logger,
+											  IEnumerable<SourceRepository> repositories,
+											  DependencyContext hostDependencies,
+											  ISet<SourcePackageDependencyInfo> availablePackages,
+											  CancellationToken cancelToken)
+	{
+		/*
+		 * Already present, skip.
+		 */
+		if (availablePackages.Contains(package))
+			return;
+
+		foreach (var sourceRepository in repositories)
+		{
+			/*
+			 * Get dependency info.
+			 */
+			var dependencyInfoResource = await sourceRepository.GetResourceAsync<DependencyInfoResource>();
+
+			var dependencyInfo = await dependencyInfoResource.ResolvePackage(
+				package,
+				framework,
+				cacheContext,
+				logger,
+				cancelToken);
+
+			if (dependencyInfo is null)
+				continue;
+			/*
+			 * Only return packages not provided by the host.
+			 */
+			var sourceDependencies = new SourcePackageDependencyInfo(
+				dependencyInfo.Id,
+				dependencyInfo.Version,
+				dependencyInfo.Dependencies.Where(dependency => !DependencySuppliedByHost(hostDependencies, dependency)),
+				dependencyInfo.Listed,
+				dependencyInfo.Source);
+
+			availablePackages.Add(sourceDependencies);
+			/*
+			 * Get the dependency's packages.
+			 */
+			foreach (var dependency in sourceDependencies.Dependencies)
+			{
+				await GetPackageDependencies(
+					new PackageIdentity(dependency.Id, dependency.VersionRange.MinVersion),
+					cacheContext,
+					framework,
+					logger,
+					repositories,
+					hostDependencies,
+					availablePackages,
+					cancelToken);
+			}
+
+			break;
+		}
+	}
+	/// <summary>
+	/// Checks if a package dependency is already provided by the host.
+	/// </summary>
+	/// <param name="hostDependencies">The context packages.</param>
+	/// <param name="dependency">The dependency to check for.</param>
+	/// <returns>True if the host provides the dependency, false otherwise.</returns>
+	private bool DependencySuppliedByHost(DependencyContext hostDependencies, PackageDependency dependency)
+	{
+		/*
+		 * Check runtimes for package with same id.
+		 */
+		var runtimeLib = hostDependencies.RuntimeLibraries.FirstOrDefault(r => r.Name == dependency.Id);
+
+		if (runtimeLib is null)
+			return false;
+		/*
+		 * Check for version compatibility.
+		 */
+		var parsedLibVersion = NuGetVersion.Parse(runtimeLib.Version);
+
+		if (parsedLibVersion.IsPrerelease)
+			/*
+			 * Latest and greatest. Always accept due to system compatiblity reasons.
+			 */
+			return true;
+
+		/*
+		 * Check for version compatibility.
+		 */
+		return dependency.VersionRange.Satisfies(parsedLibVersion);
+
+	}
+	/// <summary>
+	/// Loads packages from the specified repositories into memory.
+	/// </summary>
+	/// <param name="packages">A list of package Id and version descriptors to load.</param>
+	/// <param name="repositories">A list of NuGet repositories to check.</param>
+	internal static async Task LoadPackages(IEnumerable<MicroServiceDescriptor> packages, IEnumerable<string> repositories)
+	{
+		await new DependencyLoader().Load(packages, repositories);
+	}
+}

src/Connected.Host/Program.cs

@@ -1,67 +1,42 @@
-using System.Reflection;
 using Connected.Host.Configuration;
 
 namespace Connected.Host
 {
-	public static class Program
+	public static partial class Program
 	{
-		public static void Main(params string[] args)
+		public static async Task Main(params string[] args)
 		{
-			SysConfiguration.Build();
+			using IHost host = Microsoft.Extensions.Hosting.Host
+				.CreateDefaultBuilder(args)
+				.ConfigureAppConfiguration((_, cfg) =>
+				{
+					var appPath = AppContext.BaseDirectory;
+					var segments = new Uri(appPath).Segments;
 
-			Start(ParseArguments(args));
+					segments = segments.Select(e => e.Replace("%20", " ")).ToArray();
+
+					for (var i = 1; i <= segments.Length; i++)
+					{
+						var pathBase = Path.Combine(segments[0..i]);
+						var filePath = Path.Combine(pathBase, "sys.json");
+
+						if (File.Exists(filePath))
+						{
+							cfg.AddJsonFile(filePath, true, false);
+							break;
+						}
 					}
 
-		private static void Start(Dictionary<string, string> args)
+					cfg.AddEnvironmentVariables();
+				})
+				.ConfigureServices((context, services) =>
 				{
-			foreach (var microService in SysConfiguration.MicroServices)
+					services.Configure<SysConfiguration>(context.Configuration);
-				LoadMicroServiceAssembly(microService);
+					services.AddHostedService<ConnectedPlatformService>();
+				})
+				.Build();
 
-			if (Type.GetType(SysConfiguration.Start) is not Type startupType)
+			await host.RunAsync();
-				throw new Exception($"Cannot resolve startup type. ({SysConfiguration.Start}).");
-
-			if (startupType.GetMethod("ConfigureAsync", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic) is not MethodInfo configureMethod)
-				throw new Exception($"ConfigureAsync does not exists in the startup type {startupType}. Startup must have static 'async Task ConfigureAsync(params string[] args)' method.");
-
-			if (configureMethod.Invoke(null, new object[] { args }) is not Task task)
-				throw new Exception($"ConfigureAsync of type {startupType} must return Task.");
-
-			task.ConfigureAwait(false);
-
-			task.GetType().GetProperty("Result")?.GetValue(task);
 		}
-
-		private static Assembly? LoadMicroServiceAssembly(MicroServiceDescriptor descriptor)
-		{
-			var assemblyFile = descriptor.Name.EndsWith(".dll") ? descriptor.Name : $"{descriptor.Name}.dll";
-
-			foreach (var location in SysConfiguration.Locations)
-			{
-				var assemblyPath = Path.Combine(location, assemblyFile);
-
-				if (File.Exists(assemblyPath))
-					return Assembly.LoadFrom(assemblyPath);
-			}
-
-			return Assembly.Load(AssemblyName.GetAssemblyName(assemblyFile));
-		}
-
-		private static Dictionary<string, string> ParseArguments(params string[] args)
-		{
-			var result = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-
-			foreach (var i in args)
-			{
-				var tokens = i.Split('=', 2);
-
-				if (tokens.Length == 1)
-					result.Add(tokens[0].Trim(), string.Empty);
-				else
-					result.Add(tokens[0].Trim(), tokens[1].Trim());
-			}
-
-			return result;
-		}
-
 	}
 }

src/Connected.Host/sys.json

@@ -1,153 +1,29 @@
 {
+  "repositories": [
+    "c:/nuget/packages",
+    "https://api.nuget.org/v3/index.json"
+  ],
   "microServices": [
-    {
-      "name": "Connected",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Caching",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Collections",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Configuration",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Data",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Entities",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Globalization",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Hosting",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Interop",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Middleware",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Net",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Notifications",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Rest",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Runtime",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Security",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.ServiceModel",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Services",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Threading",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Validation",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Instance",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Common",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Common.Model",
-      "version": "1.0.0.0"
-    },
     {
       "name": "Connected.Common.Types",
-      "version": "1.0.0.0"
+      "version": "1.0.*-*"
-    },
-    {
-      "name": "Connected.Common.Types.Model",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Logistics.Documents",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Logistics.Processes.Receive",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Contacts.Types",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Logistics.Types",
-      "version": "1.0.0.0"
-    },
-    {
-      "name": "Connected.Logistics.Stock",
-      "version": "1.0.0.0"
     },
     {
       "name": "Connected.Common.Notes",
-      "version": "1.0.0.0"
+      "version": "1.0.*-*"
-    },
-    {
-      "name": "Connected.Common.Notes.Model",
-      "version": "1.0.0.0"
     },
     {
       "name": "Connected.ServiceModel.Client.Data",
-      "version": "1.0.0.0"
+      "version": "1.0.*-*"
     },
     {
       "name": "Connected.ServiceModel.Client",
-      "version": "1.0.0.0"
+      "version": "1.0.*-*"
+    },
+    {
+      "name": "Connected.Instance",
+      "version": "1.0.*-*"
     }
   ],
-  "locations": [
-    "D:\\Connected\\Connected.Framework\\Connected.Instance\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Framework\\Connected.Entities\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Framework\\Connected.Rest\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Framework.ServiceModel\\Connected.ServiceModel\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Common\\Connected.Common\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Common.Types\\Connected.Common.Types\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Common\\Connected.Common.Notes\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Logistics\\Connected.Logistics.Processes.Receive\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Logistics\\Connected.Logistics.Documents\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Logistics\\Connected.Logistics.Types\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Logistics\\Connected.Logistics.Stock\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Customers\\Connected.Contacts.Types\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Framework.ServiceModel.Client\\Connected.ServiceModel.Client\\bin\\Debug\\net7.0",
-    "D:\\Connected\\Connected.Framework.ServiceModel.Client\\Connected.ServiceModel.Client.Data\\bin\\Debug\\net7.0"
-  ],
   "start": "Connected.Instance.Start, Connected.Instance"
 }