Update the bootstrapper to install the compiled version of KoreBuild

.gitignore

@@ -39,3 +39,4 @@ web.Release.config
 .vscode/
 global.json
 nginx.*.log
+korebuild-lock.txt

build.cmd

@@ -1,2 +1,2 @@
 @ECHO OFF
-PowerShell -NoProfile -NoLogo -ExecutionPolicy unrestricted -Command "[System.Threading.Thread]::CurrentThread.CurrentCulture = ''; [System.Threading.Thread]::CurrentThread.CurrentUICulture = '';& '%~dp0build.ps1' %*; exit $LASTEXITCODE"
+PowerShell -NoProfile -NoLogo -ExecutionPolicy unrestricted -Command "[System.Threading.Thread]::CurrentThread.CurrentCulture = ''; [System.Threading.Thread]::CurrentThread.CurrentUICulture = '';& '%~dp0build.ps1' %*; exit $LASTEXITCODE"

build.ps1

@@ -1,67 +1,177 @@
-$ErrorActionPreference = "Stop"
-
-function DownloadWithRetry([string] $url, [string] $downloadLocation, [int] $retries)
-{
-    while($true)
-    {
-        try
-        {
-            Invoke-WebRequest $url -OutFile $downloadLocation
-            break
-        }
-        catch
-        {
-            $exceptionMessage = $_.Exception.Message
-            Write-Host "Failed to download '$url': $exceptionMessage"
-            if ($retries -gt 0) {
-                $retries--
-                Write-Host "Waiting 10 seconds before retrying. Retries left: $retries"
-                Start-Sleep -Seconds 10
+#!/usr/bin/env powershell
+#requires -version 4
+
+<#
+.SYNOPSIS
+Build this repository
+
+.DESCRIPTION
+Downloads korebuild if required. Then builds the repository.
+
+.PARAMETER Path
+The folder to build. Defaults to the folder containing this script.
+
+.PARAMETER Channel
+The channel of KoreBuild to download. Overrides the value from the config file.
+
+.PARAMETER DotNetHome
+The directory where .NET Core tools will be stored.
+
+.PARAMETER ToolsSource
+The base url where build tools can be downloaded. Overrides the value from the config file.
+
+.PARAMETER Update
+Updates KoreBuild to the latest version even if a lock file is present.
+
+.PARAMETER ConfigFile
+The path to the configuration file that stores values. Defaults to version.xml.
+
+.PARAMETER MSBuildArgs
+Arguments to be passed to MSBuild
+
+.NOTES
+This function will create a file $PSScriptRoot/korebuild-lock.txt. This lock file can be committed to source, but does not have to be.
+When the lockfile is not present, KoreBuild will create one using latest available version from $Channel.
+
+The $ConfigFile is expected to be an XML file. It is optional, and the configuration values in it are optional as well.
+
+.EXAMPLE
+Example config file:
+```xml
+<!-- version.xml -->
+<Project>
+  <PropertyGroup>
+    <KoreBuildChannel>dev</KoreBuildChannel>
+    <KoreBuildToolsSource>https://aspnetcore.blob.core.windows.net/buildtools</KoreBuildToolsSource>
+  </PropertyGroup>
+</Project>
+```
+#>
+[CmdletBinding(PositionalBinding = $false)]
+param(
+    [string]$Path = $PSScriptRoot,
+    [Alias('c')]
+    [string]$Channel,
+    [Alias('d')]
+    [string]$DotNetHome,
+    [Alias('s')]
+    [string]$ToolsSource,
+    [Alias('u')]
+    [switch]$Update,
+    [string]$ConfigFile = (Join-Path $PSScriptRoot 'version.xml'),
+    [Parameter(ValueFromRemainingArguments = $true)]
+    [string[]]$MSBuildArgs
+)
+
+Set-StrictMode -Version 2
+$ErrorActionPreference = 'Stop'
+
+#
+# Functions
+#
+
+function Get-KoreBuild {
+
+    $lockFile = Join-Path $Path 'korebuild-lock.txt'
+
+    if (!(Test-Path $lockFile) -or $Update) {
+        Get-RemoteFile "$ToolsSource/korebuild/channels/$Channel/latest.txt" $lockFile
+    }
+
+    $version = Get-Content $lockFile | Where-Object { $_ -like 'version:*' } | Select-Object -first 1
+    if (!$version) {
+        Write-Error "Failed to parse version from $lockFile. Expected a line that begins with 'version:'"
+    }
+    $version = $version.TrimStart('version:').Trim()
+    $korebuildPath = Join-Paths $DotNetHome ('buildtools', 'korebuild', $version)
 
+    if (!(Test-Path $korebuildPath)) {
+        Write-Host -ForegroundColor Magenta "Downloading KoreBuild $version"
+        New-Item -ItemType Directory -Path $korebuildPath | Out-Null
+        $remotePath = "$ToolsSource/korebuild/artifacts/$version/korebuild.$version.zip"
+
+        try {
+            $tmpfile = Join-Path ([IO.Path]::GetTempPath()) "KoreBuild-$([guid]::NewGuid()).zip"
+            Get-RemoteFile $remotePath $tmpfile
+            if (Get-Command -Name 'Expand-Archive' -ErrorAction Ignore) {
+                # Use built-in commands where possible as they are cross-plat compatible
+                Expand-Archive -Path $tmpfile -DestinationPath $korebuildPath
             }
-            else
-            {
-                $exception = $_.Exception
-                throw $exception
+            else {
+                # Fallback to old approach for old installations of PowerShell
+                Add-Type -AssemblyName System.IO.Compression.FileSystem
+                [System.IO.Compression.ZipFile]::ExtractToDirectory($tmpfile, $korebuildPath)
             }
         }
+        catch {
+            Remove-Item -Recurse -Force $korebuildPath -ErrorAction Ignore
+            throw
+        }
+        finally {
+            Remove-Item $tmpfile -ErrorAction Ignore
+        }
     }
+
+    return $korebuildPath
+}
+
+function Join-Paths([string]$path, [string[]]$childPaths) {
+    $childPaths | ForEach-Object { $path = Join-Path $path $_ }
+    return $path
 }
 
-cd $PSScriptRoot
+function Get-RemoteFile([string]$RemotePath, [string]$LocalPath) {
+    if ($RemotePath -notlike 'http*') {
+        Copy-Item $RemotePath $LocalPath
+        return
+    }
 
-$repoFolder = $PSScriptRoot
-$env:REPO_FOLDER = $repoFolder
+    $retries = 10
+    while ($retries -gt 0) {
+        $retries -= 1
+        try {
+            Invoke-WebRequest -UseBasicParsing -Uri $RemotePath -OutFile $LocalPath
+            return
+        }
+        catch {
+            Write-Verbose "Request failed. $retries retries remaining"
+        }
+    }
 
-$koreBuildZip="https://github.com/aspnet/KoreBuild/archive/dev.zip"
-if ($env:KOREBUILD_ZIP)
-{
-    $koreBuildZip=$env:KOREBUILD_ZIP
+    Write-Error "Download failed: '$RemotePath'."
 }
 
-$buildFolder = ".build"
-$buildFile="$buildFolder\KoreBuild.ps1"
+#
+# Main
+#
 
-if (!(Test-Path $buildFolder)) {
-    Write-Host "Downloading KoreBuild from $koreBuildZip"
+# Load configuration or set defaults
 
-    $tempFolder=$env:TEMP + "\KoreBuild-" + [guid]::NewGuid()
-    New-Item -Path "$tempFolder" -Type directory | Out-Null
+if (Test-Path $ConfigFile) {
+    [xml] $config = Get-Content $ConfigFile
+    if (!($Channel)) { [string] $Channel = Select-Xml -Xml $config -XPath '/Project/PropertyGroup/KoreBuildChannel' }
+    if (!($ToolsSource)) { [string] $ToolsSource = Select-Xml -Xml $config -XPath '/Project/PropertyGroup/KoreBuildToolsSource' }
+}
 
-    $localZipFile="$tempFolder\korebuild.zip"
+if (!$DotNetHome) {
+    $DotNetHome = if ($env:DOTNET_HOME) { $env:DOTNET_HOME } `
+        elseif ($env:USERPROFILE) { Join-Path $env:USERPROFILE '.dotnet'} `
+        elseif ($env:HOME) {Join-Path $env:HOME '.dotnet'}`
+        else { Join-Path $PSScriptRoot '.dotnet'}
+}
 
-    DownloadWithRetry -url $koreBuildZip -downloadLocation $localZipFile -retries 6
+if (!$Channel) { $Channel = 'dev' }
+if (!$ToolsSource) { $ToolsSource = 'https://aspnetcore.blob.core.windows.net/buildtools' }
 
-    Add-Type -AssemblyName System.IO.Compression.FileSystem
-    [System.IO.Compression.ZipFile]::ExtractToDirectory($localZipFile, $tempFolder)
+# Execute
 
-    New-Item -Path "$buildFolder" -Type directory | Out-Null
-    copy-item "$tempFolder\**\build\*" $buildFolder -Recurse
+$korebuildPath = Get-KoreBuild
+Import-Module -Force -Scope Local (Join-Path $korebuildPath 'KoreBuild.psd1')
 
-    # Cleanup
-    if (Test-Path $tempFolder) {
-        Remove-Item -Recurse -Force $tempFolder
-    }
+try {
+    Install-Tools $ToolsSource $DotNetHome
+    Invoke-RepositoryBuild $Path @MSBuildArgs
+}
+finally {
+    Remove-Module 'KoreBuild' -ErrorAction Ignore
 }
-
-&"$buildFile" @args