Automatically inject ASP.NET version from KoreBuild lineup into template nupkg files

Templating.sln

@@ -13,6 +13,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.DotNet.Web.Projec
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "TemplatePackages", "TemplatePackages", "{0AD6E692-E423-408C-B523-DAFB19412E4B}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DependencyUpdater", "tools\DependencyUpdater\DependencyUpdater.csproj", "{15806338-550D-4418-99AE-42FDAE03808A}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -35,6 +37,10 @@ Global
 		{62D00388-8824-4661-8CC8-8D8436FF97E6}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{62D00388-8824-4661-8CC8-8D8436FF97E6}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{62D00388-8824-4661-8CC8-8D8436FF97E6}.Release|Any CPU.Build.0 = Release|Any CPU
+		{15806338-550D-4418-99AE-42FDAE03808A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{15806338-550D-4418-99AE-42FDAE03808A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{15806338-550D-4418-99AE-42FDAE03808A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{15806338-550D-4418-99AE-42FDAE03808A}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/Directory.Build.props

@@ -10,8 +10,9 @@
     <NoWarn>2008;8021</NoWarn>
     <PackageVersion Condition="'$(VersionSuffix)' == ''">$(VersionPrefix)</PackageVersion>
     <PackageVersion Condition="'$(VersionSuffix)' != ''">$(VersionPrefix)-$(VersionSuffix)</PackageVersion>
-    <PackageOutputPath Condition="'$(PackageOutputPath)' == ''">$(MSBuildThisFileDirectory)..\artifacts\</PackageOutputPath>
+    <PackageOutputPath Condition="'$(PackageOutputPath)' == ''">$(MSBuildThisFileDirectory)..\artifacts\tmp\</PackageOutputPath>    
     <NuspecProperties>version=$(PackageVersion)</NuspecProperties>
+    <AspNetCoreVersionFromLineup>@(PackageReference->WithMetadataValue('Identity', 'Microsoft.AspNetCore.All')->Metadata('Version'))</AspNetCoreVersionFromLineup>
 
     <!--
         These are not regular projects. They are just wrappers for the .nuspec files in each
@@ -26,8 +27,15 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Remove="Microsoft.NETCore.App" />
+    <ProjectReference Include="$(MSBuildThisFileDirectory)../tools/DependencyUpdater/DependencyUpdater.csproj" />
     <None Include="Content/**" />
+
+    <!--
+      Having this package reference causes KoreBuild to pick the applicable
+      ASP.NET Core version from the lineup, making it possible to declare
+      the AspNetCoreVersionFromLineup variable above.
+    -->
+    <PackageReference Include="Microsoft.AspNetCore.All" />
   </ItemGroup>
 
 </Project>

src/Directory.Build.targets

@@ -0,0 +1,21 @@
+<Project>
+  <Import Project="..\Directory.Build.targets" />
+
+  <!--
+    Once we've written each template .nupkg file, we modify the ASP.NET references
+    in its .csproj content files, injecting whatever version number exists in
+    the curent build context.
+  -->
+
+  <UsingTask
+    TaskName="DependencyUpdater.UpdateAspNetReference"
+    AssemblyFile="$(MSBuildProjectDirectory)\$(OutputPath)DependencyUpdater.dll" />
+
+  <Target Name="RunTask" AfterTargets="Pack">
+    <UpdateAspNetReference
+        NupkgFile="$(PackageOutputPath)$(MSBuildProjectName).$(PackageVersion).nupkg"
+        AspNetVersion="$(AspNetCoreVersionFromLineup)"
+        OutDir="$(PackageOutputPath)..\" />
+  </Target>
+
+</Project>

src/Microsoft.DotNet.Web.ProjectTemplates.2.0/content/EmptyWeb-CSharp/Company.WebApplication1.csproj

@@ -10,10 +10,10 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkOverride)' == ''">
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkOverride)' != ''">
-    <PackageReference Include="Microsoft.AspNetCore" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
 
 </Project>

src/Microsoft.DotNet.Web.ProjectTemplates.2.0/content/EmptyWeb-FSharp/Company.WebApplication1.fsproj

@@ -11,7 +11,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
 
 </Project>

src/Microsoft.DotNet.Web.ProjectTemplates.2.0/content/RazorPagesWeb-CSharp/Company.WebApplication1.csproj

@@ -10,19 +10,19 @@
     <None Update="app.db" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkOverride)' == ''">
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="$(TemplateAspNetCoreVersion)" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.0" PrivateAssets="All" Condition="'$(IndividualAuth)' == 'True'" />
     <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.0.0" PrivateAssets="All" Condition="'$(IndividualAuth)' == 'True'" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkOverride)' != ''">
-    <PackageReference Include="Microsoft.AspNetCore" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="2.0.0" Condition="'$(IndividualAuth)' == 'True' OR '$(OrganizationalAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="$(TemplateAspNetCoreVersion)" Condition="'$(IndividualAuth)' == 'True' OR '$(OrganizationalAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="2.0.0" Condition="'$(OrganizationalAuth)' == 'True' OR '$(IndividualB2CAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="$(TemplateAspNetCoreVersion)" Condition="'$(OrganizationalAuth)' == 'True' OR '$(IndividualB2CAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="2.0.0" Condition="'$(IndividualLocalAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="$(TemplateAspNetCoreVersion)" Condition="'$(IndividualLocalAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="2.0.0" Condition="'$(IndividualLocalAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="$(TemplateAspNetCoreVersion)" Condition="'$(IndividualLocalAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="2.0.0" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="$(TemplateAspNetCoreVersion)" PrivateAssets="All" />
-    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="$(TemplateAspNetCoreVersion)" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.0.0" PrivateAssets="All" Condition="'$(IndividualLocalAuth)' == 'True'" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.0.0" Condition=" '$(IndividualLocalAuth)' == 'True' AND '$(UseLocalDB)' != 'True'" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="2.0.0" Condition=" '$(IndividualLocalAuth)' == 'True' AND '$(UseLocalDB)' == 'True'" />

src/Microsoft.DotNet.Web.ProjectTemplates.2.0/content/StarterWeb-CSharp/Company.WebApplication1.csproj

@@ -15,19 +15,19 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkOverride)' == ''">
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="$(TemplateAspNetCoreVersion)" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.0" PrivateAssets="All" Condition="'$(IndividualAuth)' == 'True'" />
     <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.0.0" PrivateAssets="All" Condition="'$(IndividualAuth)' == 'True'" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkOverride)' != ''">
-    <PackageReference Include="Microsoft.AspNetCore" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="2.0.0" Condition="'$(IndividualAuth)' == 'True' OR '$(OrganizationalAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="$(TemplateAspNetCoreVersion)" Condition="'$(IndividualAuth)' == 'True' OR '$(OrganizationalAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="2.0.0" Condition="'$(OrganizationalAuth)' == 'True' OR '$(IndividualB2CAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="$(TemplateAspNetCoreVersion)" Condition="'$(OrganizationalAuth)' == 'True' OR '$(IndividualB2CAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="2.0.0" Condition="'$(IndividualLocalAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="$(TemplateAspNetCoreVersion)" Condition="'$(IndividualLocalAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="2.0.0" Condition="'$(IndividualLocalAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="$(TemplateAspNetCoreVersion)" Condition="'$(IndividualLocalAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="2.0.0" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="$(TemplateAspNetCoreVersion)" PrivateAssets="All" />
-    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="$(TemplateAspNetCoreVersion)" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.0.0" PrivateAssets="All" Condition="'$(IndividualLocalAuth)' == 'True'" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.0.0" Condition=" '$(IndividualLocalAuth)' == 'True' AND '$(UseLocalDB)' != 'True'" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="2.0.0" Condition=" '$(IndividualLocalAuth)' == 'True' AND '$(UseLocalDB)' == 'True'" />

src/Microsoft.DotNet.Web.ProjectTemplates.2.0/content/StarterWeb-FSharp/Company.WebApplication1.fsproj

@@ -14,13 +14,13 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkOverride)' == ''">
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkOverride)' != ''">
-    <PackageReference Include="Microsoft.AspNetCore" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="2.0.0" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="$(TemplateAspNetCoreVersion)" PrivateAssets="All" />
-    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
 
 </Project>

src/Microsoft.DotNet.Web.ProjectTemplates.2.0/content/WebApi-CSharp/Company.WebApplication1.csproj

@@ -13,12 +13,12 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkOverride)' == ''">
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkOverride)' != ''">
-    <PackageReference Include="Microsoft.AspNetCore" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="2.0.0" Condition="'$(OrganizationalAuth)' == 'True' OR '$(IndividualB2CAuth)' == 'True'" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="$(TemplateAspNetCoreVersion)" Condition="'$(OrganizationalAuth)' == 'True' OR '$(IndividualB2CAuth)' == 'True'" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
 
   <ItemGroup>

src/Microsoft.DotNet.Web.ProjectTemplates.2.0/content/WebApi-FSharp/Company.WebApplication1.fsproj

@@ -12,11 +12,11 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkOverride)' == ''">
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkOverride)' != ''">
-    <PackageReference Include="Microsoft.AspNetCore" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="$(TemplateAspNetCoreVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="$(TemplateAspNetCoreVersion)" />
   </ItemGroup>
 
 </Project>

tools/DependencyUpdater/DependencyUpdater.csproj

@@ -1,6 +1,11 @@
 <Project Sdk="Microsoft.Net.Sdk">
   <PropertyGroup>
-    <TargetFramework>netcoreapp1.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
-    <OutputType>Exe</OutputType>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Build.Framework" />
+    <PackageReference Include="Microsoft.Build.Utilities.Core" />
+  </ItemGroup>
 </Project>

tools/DependencyUpdater/EncodingUtil.cs

@@ -1,66 +0,0 @@
-using System.Text;
-
-namespace DependencyUpdater
-{
-    public class EncodingUtil
-    {
-        /// <remarks>http://www.unicode.org/faq/utf_bom.html</remarks>
-        public static Encoding Detect(byte[] buffer, int currentBufferLength, out byte[] bom)
-        {
-            if (currentBufferLength == 0)
-            {
-                //File is zero length - pick something
-                bom = new byte[0];
-                return Encoding.UTF8;
-            }
-
-            if (currentBufferLength >= 4)
-            {
-                if (buffer[0] == 0x00 && buffer[1] == 0x00 && buffer[2] == 0xFE && buffer[3] == 0xFF)
-                {
-                    //Big endian UTF-32
-                    bom = new byte[] { 0x00, 0x00, 0xFE, 0xFF };
-                    return Encoding.GetEncoding(12001);
-                }
-
-                if (buffer[0] == 0xFF && buffer[1] == 0xFE && buffer[2] == 0x00 && buffer[3] == 0x00)
-                {
-                    //Little endian UTF-32
-                    bom = new byte[] { 0xFF, 0xFE, 0x00, 0x00 };
-                    return Encoding.UTF32;
-                }
-            }
-
-            if (currentBufferLength >= 3)
-            {
-                if (buffer[0] == 0xEF && buffer[1] == 0xBB && buffer[2] == 0xBF)
-                {
-                    //UTF-8
-                    bom = new byte[] { 0xEF, 0xBB, 0xBF };
-                    return Encoding.UTF8;
-                }
-            }
-
-            if (currentBufferLength >= 2)
-            {
-                if (buffer[0] == 0xFE && buffer[1] == 0xFF)
-                {
-                    //Big endian UTF-16
-                    bom = new byte[] { 0xFE, 0xFF };
-                    return Encoding.BigEndianUnicode;
-                }
-
-                if (buffer[0] == 0xFF && buffer[1] == 0xFE)
-                {
-                    //Little endian UTF-16
-                    bom = new byte[] { 0xFF, 0xFE };
-                    return Encoding.Unicode;
-                }
-            }
-
-            //Fallback to UTF-8
-            bom = new byte[0];
-            return Encoding.UTF8;
-        }
-    }
-}

tools/DependencyUpdater/Program.cs

@@ -1,108 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Text;
-using System.Text.RegularExpressions;
-
-namespace DependencyUpdater
-{
-    class Program
-    {
-        static int Main(string[] args)
-        {
-            if(args.Length < 2)
-            {
-                Console.WriteLine(@"Usage:
-dotnet DependencyUpdater.dll [path to templates:string] [infer no-timestamp packages from semaphore files] [[paths to package sources]]");
-                return -1;
-            }
-
-            bool NoTimestamp = bool.Parse(args[1]);
-            string root = args[0];
-            List<string> sources = new List<string>();
-
-            foreach(string arg in args.Skip(2))
-            {
-                if (Directory.Exists(arg))
-                {
-                    sources.Add(arg);
-                }
-                else if (File.Exists(arg))
-                {
-                    string sem = File.ReadAllText(arg);
-
-                    foreach (string line in sem.Split('\n'))
-                    {
-                        string trimmed = line.Trim();
-                        string share = trimmed.Substring(trimmed.LastIndexOf(':') + 1).Trim();
-                        string source = Path.Combine(share, @"Signed\Packages") + (NoTimestamp ? "-NoTimeStamp" : "");
-
-                        if (Directory.Exists(source))
-                        {
-                            sources.Add(source);
-                        }
-                    }
-                }
-                else
-                {
-                    Console.Error.WriteLine($"Unknown source: \"{arg}\"");
-                }
-            }
-
-            Regex versionPattern = new Regex(@"\d+\.\d+\.\d+([-\+].*)?");
-            List<Tuple<string, Regex, string>> replacements = new List<Tuple<string, Regex, string>>();
-
-            foreach (string source in sources)
-            {
-                foreach (string file in Directory.EnumerateFiles(source, "*.nupkg", SearchOption.AllDirectories))
-                {
-                    string packageIdAndVersion = Path.GetFileNameWithoutExtension(file);
-                    Match m = versionPattern.Match(packageIdAndVersion);
-                    string packageId = packageIdAndVersion.Substring(0, m.Index).TrimEnd('.');
-                    string version = packageIdAndVersion.Substring(m.Index);
-                    int versionFirstDot = version.IndexOf('.');
-                    int versionSecondDot = version.IndexOf('.', versionFirstDot + 1);
-                    string majorMinor = version.Substring(0, versionSecondDot);
-                    string majorMinorEscaped = Regex.Escape(majorMinor);
-
-                    Regex rx = new Regex($"(?<=\"{packageId}\"\\s+Version\\s*=\\s*\"){majorMinorEscaped}[^\"]*(?=\")");
-                    replacements.Add(Tuple.Create(packageId, rx, version));
-                }
-            }
-
-            foreach(string project in Directory.EnumerateFiles(root, "*.*proj", SearchOption.AllDirectories))
-            {
-                if(Path.GetExtension(project).ToUpperInvariant() == ".PROJ" || Path.GetFileName(project).ToUpperInvariant() == "BUILD.CSPROJ")
-                {
-                    continue;
-                }
-
-                string source = File.ReadAllText(project);
-                string result = source;
-                foreach(Tuple<string, Regex, string> replacement in replacements)
-                {
-                    string orig = result;
-                    result = replacement.Item2.Replace(result, replacement.Item3);
-
-                    if(orig != result)
-                    {
-                        Console.WriteLine($"{project.Substring(root.Length).TrimStart('\\', '/')}: {replacement.Item1} -> {replacement.Item3}");
-                    }
-                }
-
-                byte[] data = File.ReadAllBytes(project);
-                Encoding encoding = EncodingUtil.Detect(data, data.Length, out byte[] bom);
-
-                if(bom.Length == 0 && Encoding.UTF8.EncodingName == encoding.EncodingName)
-                {
-                    encoding = new UTF8Encoding(false);
-                }
-
-                File.WriteAllText(project, result, encoding);
-            }
-
-            return 0;
-        }
-    }
-}

tools/DependencyUpdater/UpdateAspNetReference.cs

@@ -0,0 +1,78 @@
+using Microsoft.Build.Utilities;
+using System;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+
+namespace DependencyUpdater
+{
+    public class UpdateAspNetReference : Task
+    {
+        private static string[] ProjectFileExtensions = new[]
+        {
+            ".csproj",
+            ".fsproj"
+        };
+
+        public string NupkgFile { get; set; }
+        public string AspNetVersion { get; set; }
+        public string OutDir { get; set; }
+
+        public override bool Execute()
+        {
+            if (string.IsNullOrEmpty(AspNetVersion))
+            {
+                throw new ArgumentException($"No value specified for {nameof(AspNetVersion)}.");
+            }
+
+            // We can't modify the .nupkg in place because the build system still
+            // has a lock on the file. We can read it, but not write it. So copy
+            // to the output location and then modify the copy.
+            var outFile = Path.Combine(OutDir, Path.GetFileName(NupkgFile));
+            File.Copy(NupkgFile, outFile, true);
+            
+            using (var zipFile = ZipFile.Open(outFile, ZipArchiveMode.Update))
+            {
+                foreach (var projectFile in zipFile.Entries.Where(IsProjectFile))
+                {
+                    PerformVariableSubstitution(projectFile);
+                }
+            }
+
+            return true;
+        }
+
+        private static bool IsProjectFile(ZipArchiveEntry entry)
+        {
+            return ProjectFileExtensions.Any(
+                extension => Path.GetExtension(entry.Name).Equals(extension, StringComparison.OrdinalIgnoreCase));
+        }
+
+        private void PerformVariableSubstitution(ZipArchiveEntry entry)
+        {
+            using (var fileStream = entry.Open())
+            {
+                string contents;
+                using (var reader = new StreamReader(fileStream))
+                using (var writer = new StreamWriter(fileStream))
+                {
+                    contents = reader.ReadToEnd();
+                    fileStream.Seek(0, SeekOrigin.Begin);
+                    fileStream.SetLength(0);
+                    writer.Write(SubstituteVariables(contents));
+                }
+            }
+        }
+
+        private string SubstituteVariables(string projectFileContents)
+        {
+            // Currently we only need a way of updating ASP.NET package
+            // reference versions, so that's all this does. In the future,
+            // we could generalise this into a system for injecting
+            // versions for all packages based on the KoreBuild lineup.
+            return projectFileContents.Replace(
+                "$(TemplateAspNetCoreVersion)",
+                AspNetVersion);
+        }
+    }
+}