[WIP] GH2028: adding credential support for inprocess nuget client (please don't merge)

src/Cake.NuGet/Cake.NuGet.csproj

@@ -19,6 +19,7 @@
   </ItemGroup>
   <!-- Global packages -->
   <ItemGroup>
+    <PackageReference Include="NuGet.Credentials" Version="4.6.0" />
     <PackageReference Include="NuGet.Frameworks" Version="4.6.0" />
     <PackageReference Include="NuGet.Versioning" Version="4.6.0" />
     <PackageReference Include="NuGet.ProjectModel" Version="4.6.0" />

src/Cake.NuGet/Install/NuGetExtensionLocator.cs

@@ -0,0 +1,120 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+using Cake.Core;
+using Cake.Core.Configuration;
+
+using NuGet.Configuration;
+
+namespace Cake.NuGet.Install
+{
+    /// <summary>
+    /// Provides a common facility for locating extensions
+    /// </summary>
+    internal sealed class NuGetExtensionLocator : IExtensionLocator // shamelessly copied from nuget source repo
+    {
+        private readonly ICakeConfiguration _config;
+        private readonly ICakeEnvironment _environment;
+
+        private static readonly string _extensionsDirectoryRoot =
+            Path.Combine(Environment.GetFolderPath(
+                Environment.SpecialFolder.LocalApplicationData),
+                "NuGet",
+                "Commands");
+
+        private static readonly string _credentialProvidersDirectoryRoot =
+            Path.Combine(Environment.GetFolderPath(
+                Environment.SpecialFolder.LocalApplicationData),
+                "NuGet",
+                "CredentialProviders");
+
+        private static readonly string CredentialProviderPattern = "CredentialProvider*.exe";
+
+        /// <summary>
+        /// PATH Enviroment variable name for path to nuget extensions
+        /// </summary>
+        public static readonly string ExtensionsEnvar = "NUGET_EXTENSIONS_PATH";
+
+        /// <summary>
+        /// PATH Enviroment variable name for path to nuget credentials providers
+        /// </summary>
+        public static readonly string CredentialProvidersEnvar = "NUGET_CREDENTIALPROVIDERS_PATH";
+
+        public NuGetExtensionLocator(ICakeEnvironment environment, ICakeConfiguration config)
+        {
+            _environment = environment ?? throw new ArgumentNullException(nameof(environment));
+            _config = config ?? throw new ArgumentNullException(nameof(config));
+        }
+
+        /// <inheritdoc/>
+        public IEnumerable<string> FindCredentialProviders()
+        {
+            var customPaths = ReadPathsFromEnvar(CredentialProvidersEnvar);
+            return FindAll(
+                _credentialProvidersDirectoryRoot,
+                customPaths,
+                CredentialProviderPattern,
+                CredentialProviderPattern
+                );
+        }
+
+        /// <inheritdoc/>
+        public IEnumerable<string> FindExtensions()
+        {
+            var customPaths = ReadPathsFromEnvar(ExtensionsEnvar);
+            return FindAll(
+                _extensionsDirectoryRoot,
+                customPaths,
+                "*.dll",
+                "*Extensions.dll"
+                );
+        }
+
+        private IEnumerable<string> FindAll(
+            string globalRootDirectory,
+            IEnumerable<string> customPaths,
+            string assemblyPattern,
+            string nugetDirectoryAssemblyPattern)
+        {
+            var directories = new List<string>();
+
+            // Add all directories from the environment variable if available.
+            directories.AddRange(customPaths);
+
+            // add the global root
+            directories.Add(globalRootDirectory);
+
+            var paths = new List<string>();
+            foreach (var directory in directories.Where(Directory.Exists))
+            {
+                paths.AddRange(Directory.EnumerateFiles(directory, assemblyPattern, SearchOption.AllDirectories));
+            }
+
+            // not sure if the working directory is an appropriate fallback for locating the tools/folder nuget/folder
+            var nugetDirectory = Path.GetDirectoryName(_config.GetToolPath(_environment.WorkingDirectory, _environment).FullPath); // directory for locating extensions and credentials providers, such as VSTS CredentialProvider
+            if (nugetDirectory == null)
+            {
+                return paths;
+            }
+
+            paths.AddRange(Directory.EnumerateFiles(nugetDirectory, nugetDirectoryAssemblyPattern));
+
+            return paths;
+        }
+
+        private static IEnumerable<string> ReadPathsFromEnvar(string key)
+        {
+            var result = new List<string>();
+            var paths = Environment.GetEnvironmentVariable(key);
+            if (!string.IsNullOrEmpty(paths))
+            {
+                result.AddRange(
+                    paths.Split(new[] { ';' },
+                    StringSplitOptions.RemoveEmptyEntries));
+            }
+            return result;
+        }
+    }
+}

src/Cake.NuGet/Install/NuGetPackageInstaller.cs

@@ -6,21 +6,24 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
-using System.Threading.Tasks;
+
 using Cake.Core;
 using Cake.Core.Configuration;
 using Cake.Core.Diagnostics;
 using Cake.Core.IO;
 using Cake.NuGet.Install.Extensions;
+
 using NuGet.Common;
 using NuGet.Configuration;
+using NuGet.Credentials;
 using NuGet.Frameworks;
 using NuGet.PackageManagement;
 using NuGet.Packaging;
 using NuGet.Packaging.Core;
 using NuGet.Protocol.Core.Types;
 using NuGet.Resolver;
 using NuGet.Versioning;
+
 using PackageReference = Cake.Core.Packaging.PackageReference;
 using PackageType = Cake.Core.Packaging.PackageType;
 
@@ -131,6 +134,10 @@ public IReadOnlyCollection<IFile> Install(PackageReference package, PackageType
 
             var resolutionContext = new ResolutionContext(dependencyBehavior, includePrerelease, false, VersionConstraints.None, _gatherCache, _sourceCacheContext);
             var downloadContext = new PackageDownloadContext(_sourceCacheContext);
+            // WIP
+            var extensionLocator = new NuGetExtensionLocator(_environment, _config);
+            var pluginCredentialProviderBuilder = new PluginCredentialProviderBuilder(extensionLocator, _nugetSettings, _nugetLogger);
+            var credentialProviders = pluginCredentialProviderBuilder.BuildAll("verbose");
 
             // First get the install actions.
             // This will give us the list of packages to install, and which feed should be used.