Support for Claude in Docker.

Author: gfraiteur

.claude/settings.local.json

@@ -9,7 +9,14 @@
       "Bash(dotnet build:*)",
       "Bash(winget search:*)",
       "Bash(git -C \"X:\\src\\PostSharp.Engineering\" diff --stat)",
-      "Bash(git -C \"X:\\src\\PostSharp.Engineering\" log --oneline -20)"
+      "Bash(git -C \"X:\\src\\PostSharp.Engineering\" log --oneline -20)",
+      "WebSearch",
+      "Bash(ForEach-Object { docker rmi $_ -f })",
+      "Bash(docker images:*)",
+      "Bash(findstr:*)",
+      "Bash(docker run:*)",
+      "Bash(.DockerBuild.ps1 -Claude -SkipBuild)",
+      "Bash(dotnet restore:*)"
     ],
     "deny": [],
     "ask": []

.gitignore

@@ -15,6 +15,7 @@ nuget.config
 global.json
 *.g.json
 *.g.ps1
+eng/docker-context/claude.json
 scripts/build-agents/last-execution.txt
 *.log
 copilot.data.*

CLAUDE.md

@@ -8,4 +8,4 @@ The `postsharp-engineering` plugin provides skills and slash commands. To discov
 
 Before any work in this repo, read these skills:
 - `$env:USERPROFILE\.claude\plugins\cache\postsharp-engineering\**\skills\*.md` - Engineering workflows (git, builds, CI/CD)
-
+- Never update DockerBuild.ps1, Dockerfile. Dockerfile.claude, eng/RunClaude.ps1. These files are generated by `Build.ps1`. Their source code is in the Resources directory.

DockerBuild.ps1

@@ -9,15 +9,14 @@ param(
     [switch]$NoClean, # Does not clean up.
     [switch]$NoNuGetCache, # Does not mount the host nuget cache in the container.
     [switch]$KeepEnv, # Does not override the env.g.json file.
-    [switch]$Claude, # Run Claude CLI instead of Build.ps1.
-    [string]$ClaudePrompt, # Optional prompt for Claude (non-interactive mode).
+    [switch]$Claude, # Run Claude CLI instead of Build.ps1. Use -Claude for interactive, -Claude "prompt" for non-interactive.
     [string]$ImageName, # Image name (defaults to a name based on the directory).
     [string]$BuildAgentPath = 'C:\BuildAgent',
     [switch]$LoadEnvFromKeyVault, # Forces loading environment variables form the key vault.
     [switch]$StartVsmon, # Enable the remote debugger.
     [string]$Script = 'Build.ps1', # The build script to be executed inside Docker.
     [Parameter(ValueFromRemainingArguments)]
-    [string[]]$BuildArgs   # Arguments passed to `Build.ps1` within the container.
+    [string[]]$BuildArgs   # Arguments passed to `Build.ps1` within the container (or Claude prompt if -Claude is specified).
 )
 
 ####
@@ -235,9 +234,9 @@ if (-not (Test-Path $dockerContextDirectory))
 
 
 # Prepare volume mappings
-    $VolumeMappings = @("-v", "${SourceDirName}:${SourceDirName}")
-    $MountPoints = @($SourceDirName, "c:\packages")
-    $GitDirectories = @($SourceDirName)
+$VolumeMappings = @("-v", "${SourceDirName}:${SourceDirName}")
+$MountPoints = @($SourceDirName, "c:\packages")
+$GitDirectories = @($SourceDirName)
 
 # Define static Git system directory for mapping. This used by Teamcity as an LFS parent repo.
 $gitSystemDir = "$BuildAgentPath\system\git"
@@ -321,6 +320,68 @@ if (Test-Path $dockerMountsScript)
     . $dockerMountsScript
 }
 
+# Handle non-C: drive letters for Docker (Windows containers only have C: by default)
+# We mount X:\foo to C:\X\foo in the container, then use subst to create the X: drive
+$driveLetters = @{}
+
+function Get-ContainerPath($hostPath)
+{
+    if ($hostPath -match '^([A-Za-z]):(.*)$')
+    {
+        $driveLetter = $Matches[1].ToUpper()
+        $pathWithoutDrive = $Matches[2]
+        if ($driveLetter -ne 'C')
+        {
+            $driveLetters[$driveLetter] = $true
+            return "C:\$driveLetter$pathWithoutDrive"
+        }
+    }
+    return $hostPath
+}
+
+# Transform all volume mappings to use container paths
+$transformedVolumeMappings = @()
+for ($i = 0; $i -lt $VolumeMappings.Count; $i += 2)
+{
+    $flag = $VolumeMappings[$i]
+    $mapping = $VolumeMappings[$i + 1]
+
+    # Parse volume mapping: hostPath:containerPath[:options]
+    if ($mapping -match '^([A-Za-z]:\\[^:]*):([A-Za-z]:\\[^:]*)(:.+)?$')
+    {
+        $hostPath = $Matches[1]
+        $containerPath = $Matches[2]
+        $options = $Matches[3]
+        $newContainerPath = Get-ContainerPath $containerPath
+        $transformedVolumeMappings += @($flag, "${hostPath}:${newContainerPath}${options}")
+    }
+    else
+    {
+        $transformedVolumeMappings += @($flag, $mapping)
+    }
+}
+$VolumeMappings = $transformedVolumeMappings
+
+# Transform MountPoints, GitDirectories, and SourceDirName for the container
+$MountPoints = $MountPoints | ForEach-Object { Get-ContainerPath $_ }
+$GitDirectories = $GitDirectories | ForEach-Object { Get-ContainerPath $_ }
+$ContainerSourceDir = Get-ContainerPath $SourceDirName
+
+# Build subst commands string for inline execution in docker run
+$substCommandsInline = ""
+foreach ($letter in $driveLetters.Keys | Sort-Object)
+{
+    $substCommandsInline += "C:\Windows\System32\subst.exe ${letter}: C:\$letter; "
+}
+if ($driveLetters.Count -gt 0)
+{
+    Write-Host "Drive letter mappings for container: $($driveLetters.Keys -join ', ')" -ForegroundColor Cyan
+}
+
+# Create empty Init.g.ps1 for Dockerfile COPY (required by Dockerfile but not used for drive mapping)
+$initScript = Join-Path $dockerContextDirectory "Init.g.ps1"
+"# Drive mappings are handled inline in docker run command" | Set-Content -Path $initScript -Encoding UTF8
+
 $mountPointsAsString = $MountPoints -Join ";"
 $gitDirectoriesAsString = $GitDirectories -Join ";"
 
@@ -337,35 +398,35 @@ docker ps -q --filter "ancestor=$ImageTag" | ForEach-Object {
 # Building the image.
 if (-not $NoBuildImage)
 {
-    Write-Host "Building the base image with tag: $ImageTag" -ForegroundColor Green
-    Get-Content -Raw Dockerfile | docker build -t $ImageTag  --build-arg GITDIRS="$gitDirectoriesAsString"  --build-arg MOUNTPOINTS="$mountPointsAsString"  -f - $dockerContextDirectory
-    if ($LASTEXITCODE -ne 0)
-    {
-        Write-Host "Docker build failed with exit code $LASTEXITCODE" -ForegroundColor Red
-        exit $LASTEXITCODE
-    }
-
-    # Build Claude image if requested
     if ($Claude)
     {
-        $ClaudeImageTag = "$ImageTag-claude"
-        Write-Host "Building the Claude image with tag: $ClaudeImageTag" -ForegroundColor Green
+        # Build Claude image directly from standalone Dockerfile.claude
+        $ImageTag = "$ImageTag-claude"
+        Write-Host "Building the Claude image with tag: $ImageTag" -ForegroundColor Green
 
         if (-not (Test-Path "Dockerfile.claude"))
         {
-            Write-Error "Dockerfile.claude not found. Make sure generate-scripts was run with a NodeJs component."
+            Write-Error "Dockerfile.claude not found. Make sure generate-scripts was run with Claude support."
             exit 1
         }
 
-        Get-Content -Raw Dockerfile.claude | docker build -t $ClaudeImageTag --build-arg BASE_IMAGE="$ImageTag" -f - $dockerContextDirectory
+        Get-Content -Raw Dockerfile.claude | docker build -t $ImageTag --build-arg GITDIRS="$gitDirectoriesAsString" --build-arg MOUNTPOINTS="$mountPointsAsString" -f - $dockerContextDirectory
         if ($LASTEXITCODE -ne 0)
         {
             Write-Host "Docker build (Claude) failed with exit code $LASTEXITCODE" -ForegroundColor Red
             exit $LASTEXITCODE
         }
-
-        # Use Claude image for the run
-        $ImageTag = $ClaudeImageTag
+    }
+    else
+    {
+        # Build base image
+        Write-Host "Building the base image with tag: $ImageTag" -ForegroundColor Green
+        Get-Content -Raw Dockerfile | docker build -t $ImageTag --build-arg GITDIRS="$gitDirectoriesAsString" --build-arg MOUNTPOINTS="$mountPointsAsString" -f - $dockerContextDirectory
+        if ($LASTEXITCODE -ne 0)
+        {
+            Write-Host "Docker build failed with exit code $LASTEXITCODE" -ForegroundColor Red
+            exit $LASTEXITCODE
+        }
     }
 }
 else
@@ -383,7 +444,87 @@ else
 # Run the build within the container
 if (-not $BuildImage)
 {
+    if ($Claude)
+    {
+        # Run Claude mode
+        Write-Host "Running Claude in the container." -ForegroundColor Green
 
+        # Add Claude-specific volume mounts for auth and settings
+        $hostUserProfile = $env:USERPROFILE
+        $containerUserProfile = "C:\Users\ContainerUser"
+
+        # Mount .claude directory (settings and credentials)
+        if (Test-Path "$hostUserProfile\.claude")
+        {
+            $VolumeMappings += @("-v", "${hostUserProfile}\.claude:${containerUserProfile}\.claude")
+        }
+
+        # Copy .claude.json to docker-context (cannot mount files on Windows Docker)
+        # Also fix installMethod to match container's npm installation
+        $claudeJsonSource = "$hostUserProfile\.claude.json"
+        $claudeJsonDest = Join-Path $dockerContextDirectory "claude.json"
+        $copyClaudeJsonScript = ""
+        if (Test-Path $claudeJsonSource)
+        {
+            $claudeConfig = Get-Content $claudeJsonSource -Raw | ConvertFrom-Json
+            # Change installMethod to npm since that's how Claude is installed in container
+            if ($claudeConfig.installMethod)
+            {
+                $claudeConfig.installMethod = "npm"
+            }
+            $claudeConfig | ConvertTo-Json -Depth 10 | Set-Content $claudeJsonDest -Encoding UTF8
+            # Will copy from mounted source dir to user profile in container
+            $copyClaudeJsonScript = "Copy-Item '$ContainerSourceDir\eng\docker-context\claude.json' '$containerUserProfile\.claude.json' -Force; "
+        }
+
+        # Mount .cache\claude (cache)
+        if (Test-Path "$hostUserProfile\.cache\claude")
+        {
+            $VolumeMappings += @("-v", "${hostUserProfile}\.cache\claude:${containerUserProfile}\.cache\claude")
+        }
+
+        $VolumeMappingsAsString = $VolumeMappings -join " "
+
+        # Extract Claude prompt from remaining arguments if present
+        # Usage: -Claude for interactive, -Claude "prompt" for non-interactive
+        $ClaudePrompt = $null
+        if ($BuildArgs -and $BuildArgs.Count -gt 0 -and $BuildArgs[0] -and -not $BuildArgs[0].StartsWith('-'))
+        {
+            $ClaudePrompt = $BuildArgs[0]
+        }
+
+        # Build inline script: subst drives, copy claude.json, cd to source, run Claude
+        if ($ClaudePrompt)
+        {
+            # Non-interactive mode with prompt - no -it flags
+            $dockerArgs = @()
+            $inlineScript = "${substCommandsInline}${copyClaudeJsonScript}cd '$SourceDirName'; & .\eng\RunClaude.g.ps1 -Prompt `"$ClaudePrompt`""
+        }
+        else
+        {
+            # Interactive mode - requires TTY
+            $dockerArgs = @("-it")
+            $inlineScript = "${substCommandsInline}${copyClaudeJsonScript}cd '$SourceDirName'; & .\eng\RunClaude.g.ps1"
+        }
+
+        $dockerArgsAsString = $dockerArgs -join " "
+        $pwshPath = 'C:\Program Files\PowerShell\7\pwsh.exe'
+
+        # Set HOME/USERPROFILE so Claude finds its config in the mounted location
+        $envArgs = @("-e", "HOME=$containerUserProfile", "-e", "USERPROFILE=$containerUserProfile")
+
+        Write-Host "Executing: ``docker run --rm --memory=12g $dockerArgsAsString $VolumeMappingsAsString -e HOME=$containerUserProfile -e USERPROFILE=$containerUserProfile -w $ContainerSourceDir $ImageTag `"$pwshPath`" -Command `"$inlineScript`"" -ForegroundColor Cyan
+        docker run --rm --memory=12g $dockerArgs @VolumeMappings @envArgs -w $ContainerSourceDir $ImageTag $pwshPath -Command $inlineScript
+
+        if ($LASTEXITCODE -ne 0)
+        {
+            Write-Host "Docker run (Claude) failed with exit code $LASTEXITCODE" -ForegroundColor Red
+            exit $LASTEXITCODE
+        }
+    }
+    else
+    {
+        # Run standard build mode
         # Delete now and not in the container because it's much faster and lock error messages are more relevant.
         Write-Host "Building the product in the container." -ForegroundColor Green
 
@@ -404,23 +545,26 @@ if (-not $BuildImage)
         {
             $pwshArgs = "-NonInteractive"
             $dockerArgs = @()
-        $pwshExitCommand = "exit `$LASTEXITCODE`;"
+            $pwshExitCommand = "exit `$LASTEXITCODE`;"
         }
 
         $buildArgsString = $BuildArgs -join " "
         $VolumeMappingsAsString = $VolumeMappings -join " "
         $dockerArgsAsString = $dockerArgs -join " "
 
+        # Build inline script: subst drives, cd to source, run build
+        $inlineScript = "${substCommandsInline}cd '$SourceDirName'; & .\$Script $buildArgsString; $pwshExitCommand"
 
-    Write-Host "Executing: ``docker run --rm --memory=12g $dockerArgsAsString $VolumeMappingsAsString -w $SourceDirName $ImageTag pwsh $pwshArgs -Command `"& .\$Script $buildArgsString`; $pwshExitCommand`"" -ForegroundColor Cyan
+        $pwshPath = 'C:\Program Files\PowerShell\7\pwsh.exe'
+        Write-Host "Executing: ``docker run --rm --memory=12g $dockerArgsAsString $VolumeMappingsAsString -w $ContainerSourceDir $ImageTag `"$pwshPath`" $pwshArgs -Command `"$inlineScript`"" -ForegroundColor Cyan
 
-    docker run --rm --memory=12g $dockerArgs @VolumeMappings -w $SourceDirName @dockerArgs $ImageTag pwsh $pwshArgs -Command "& .\$Script $buildArgsString`; $pwshExitCommand; "
+        docker run --rm --memory=12g $dockerArgs @VolumeMappings -w $ContainerSourceDir $ImageTag $pwshPath $pwshArgs -Command $inlineScript
         if ($LASTEXITCODE -ne 0)
         {
             Write-Host "Docker run (build) failed with exit code $LASTEXITCODE" -ForegroundColor Red
             exit $LASTEXITCODE
         }
-
+    }
 }
 else
 {

Dockerfile

@@ -4,8 +4,8 @@
 
 FROM mcr.microsoft.com/windows/servercore:ltsc2025
 
-# The initial shell is PowerShell Desktop.
-SHELL ["powershell", "-Command"]
+# The initial shell is Windows PowerShell (use full path to avoid HCS issues)
+SHELL ["C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe", "-Command"]
 
 # Prepare environment
 ENV PSExecutionPolicyPreference=Bypass
@@ -14,41 +14,47 @@ ENV TEMP=C:\Temp
 ENV TMP=C:\Temp
 ENV RUNNING_IN_DOCKER=TRUE
 
+# Add Windows PowerShell to PATH (pwsh added later by PowershellComponent)
+ENV PATH="C:\Windows\System32\WindowsPowerShell\v1.0;${PATH}"
+
 # Enable long path support
 RUN Set-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Control\FileSystem' -Name 'LongPathsEnabled' -Value 1
 
 
 
 # Install Git
-RUN Invoke-WebRequest -Uri https://github.com/git-for-windows/git/releases/download/v2.50.0.windows.1/MinGit-2.50.0-64-bit.zip -OutFile MinGit.zip; `
-    Expand-Archive c:\\MinGit.zip -DestinationPath C:\\git; `
-    Remove-Item C:\\MinGit.zip; `
-    $pathsToAdd = @('C:\git\cmd', 'C:\git\bin', 'C:\git\usr\bin'); `
-    $newPath = [Environment]::GetEnvironmentVariable('PATH', 'Machine') + ';' + ($pathsToAdd -join ';'); `
-    [Environment]::SetEnvironmentVariable('PATH', $newPath, 'Machine');
-    
-RUN "C:\Git\cmd\git.exe" config --system core.longpaths true
+RUN Invoke-WebRequest -Uri https://github.com/git-for-windows/git/releases/download/v2.50.0.windows.1/PortableGit-2.50.0-64-bit.7z.exe -OutFile PortableGit.exe; `
+    Start-Process -FilePath .\PortableGit.exe -ArgumentList '-o"C:\git"', '-y' -Wait; `
+    Remove-Item PortableGit.exe
+
+# Add git to PATH using ENV directive (persists across shell switches)
+ENV PATH="C:\git\cmd;C:\git\bin;C:\git\usr\bin;${PATH}"
+
+RUN git config --system core.longpaths true
+
+# Set CLAUDE_CODE_GIT_BASH_PATH for Claude Code
+ENV CLAUDE_CODE_GIT_BASH_PATH=C:\git\bin\bash.exe
 
 
 # Install PowerShell 7
 RUN Invoke-WebRequest -Uri https://github.com/PowerShell/PowerShell/releases/download/v7.5.2/PowerShell-7.5.2-win-x64.msi -OutFile PowerShell.msi; `
     $process = Start-Process msiexec.exe -Wait -PassThru -ArgumentList '/I PowerShell.msi /quiet'; `
     if ($process.ExitCode -ne 0) { exit $process.ExitCode }; `
-    Remove-Item PowerShell.msi; `
-    $pathsToAdd = @('C:\Program Files\PowerShell\7'); `
-    $newPath = [Environment]::GetEnvironmentVariable('PATH', 'Machine') + ';' + ($pathsToAdd -join ';'); `
-    [Environment]::SetEnvironmentVariable('PATH', $newPath, 'Machine');
+    Remove-Item PowerShell.msi
+
+# Add PowerShell 7 to PATH using ENV directive (persists across shell switches)
+ENV PATH="C:\Program Files\PowerShell\7;${PATH}"
 
 
 # Download .NET Installer
-RUN Invoke-WebRequest -Uri https://dot.net/v1/dotnet-install.ps1 -OutFile dotnet-install.ps1; `
-    $pathsToAdd = @('C:\Program Files\dotnet'); `
-    $newPath = [Environment]::GetEnvironmentVariable('PATH', 'Machine') + ';' + ($pathsToAdd -join ';'); `
-    [Environment]::SetEnvironmentVariable('PATH', $newPath, 'Machine'); 
+RUN Invoke-WebRequest -Uri https://dot.net/v1/dotnet-install.ps1 -OutFile dotnet-install.ps1
+
+# Add .NET to PATH using ENV directive (persists across shell switches)
+ENV PATH="C:\Program Files\dotnet;${PATH}"
 
 
 # Install .NET Sdk 9.0.305
-RUN powershell -ExecutionPolicy Bypass -File dotnet-install.ps1 -Version 9.0.305 -InstallDir 'C:\Program Files\dotnet'; 
+RUN & .\dotnet-install.ps1 -Version 9.0.305 -InstallDir 'C:\Program Files\dotnet'
 
 
 # Epilogue
@@ -65,9 +71,12 @@ RUN if ($env:MOUNTPOINTS) { `
     }
 
 # Import environment variables
-COPY ReadEnvironmentVariables.ps1 c:\ReadEnvironmentVariables.ps1    
+COPY ReadEnvironmentVariables.ps1 c:\ReadEnvironmentVariables.ps1
 COPY env.g.json c:\env.g.json
-RUN c:\ReadEnvironmentVariables.ps1 c:\env.g.json   
+RUN c:\ReadEnvironmentVariables.ps1 c:\env.g.json
+
+# Copy Init.g.ps1 placeholder (drive mappings handled inline in docker run)
+COPY Init.g.ps1 c:\Init.g.ps1
 
 # Configure NuGet
 ENV NUGET_PACKAGES=c:\packages