windows: Fix stupid quoting issues in autounattend XML

The windows XML parser is shit and bails out extremely late, making
debugging this a 1+ hour ordeal for every iteration.

Let's just write out a powershell script and be done with it.

artiq-fast/windows/autounattend.nix

@@ -34,21 +34,18 @@ let
     )
   ) services;
 
-  # If we are running in impure mode we can also enable networked services
-  impureSetupCommands = let
+  sshSetupCommands = let
     makeDirs = lib.mapAttrsToList (n: v: ''mkdir C:\Users\${n}\.ssh'') users;
     writeKeys = lib.flatten (lib.mapAttrsToList (n: v: builtins.map (key: let
       commands = [
-        ''powershell.exe "echo ${key} | Out-File -FilePath C:\Users\${n}\.ssh\authorized_keys"''
+        ''powershell.exe Set-Content -Path C:\Users\${n}\.ssh\authorized_keys -Value '${key}' ''
       ];
     in lib.concatStringsSep "\n" commands) (v.sshKeys or [])) users);
     mkDirsDesc = builtins.map (c: {Path = c; Description = "Make SSH key dir";})  makeDirs;
     writeKeysDesc = builtins.map (c: {Path = c; Description = "Add SSH key";})  writeKeys;
-
   in mkDirsDesc ++ writeKeysDesc ++ [
-    # TODO: Figure out how to do this step with sandboxing enabled
     {
-      Path = ''Register-PSRepository -Name bootstraprepo -SourceLocation F:\files'';
+      Path = ''powershell.exe Register-PSRepository -Name bootstraprepo -SourceLocation F:\files'';
       Description = "Local powershell repo import";
     }
     {
@@ -81,7 +78,12 @@ let
       }
     ]
     ++ setupCommands
-    ++ impureSetupCommands
+    ++ [
+      {
+        Path = ''powershell.exe F:\ssh-setup.ps1'';
+        Description = "Setup SSH and keys";
+      }
+    ]
     ++ serviceCommands
     ++ impureShellCommands
   );
@@ -290,8 +292,23 @@ let
     </unattend>
   '';
 
-in
+in {
   # Lint and format as a sanity check
-pkgs.runCommandNoCC "autounattend.xml" {} ''
-  ${pkgs.libxml2}/bin/xmllint --format ${autounattendXML} > $out
-''
+  autounattendXML = pkgs.runCommandNoCC "autounattend.xml" {} ''
+    ${pkgs.libxml2}/bin/xmllint --format ${autounattendXML} > $out
+  '';
+
+  # autounattend.xml is _super_ picky about quotes and other things
+  setupScript = pkgs.writeText "ssh-setup.ps1" (
+    ''
+      # Setup SSH and keys
+    '' +
+    lib.concatStrings (
+      builtins.map (c: ''
+        # ${c.Description}
+        ${c.Path}
+      '') sshSetupCommands
+    )
+  );
+
+}

artiq-fast/windows/run-test.nix

@@ -35,7 +35,8 @@ stdenv.mkDerivation {
   name = "windows-test-runner";
 
   # Dummy sources
-  src = pkgs.runCommandNoCC "" {} "touch $out";
+  src = pkgs.runCommandNoCC "dummy" {} "touch $out";
+  dontUnpack = true;
 
   propagatedBuildInputs = qemu.inputs;
   dontBuild = true;

artiq-fast/windows/win.nix

@@ -81,6 +81,10 @@ let
       mkdir pkgs/files
 
       cp ${bundleInstaller} pkgs/"$(stripHash "${bundleInstaller}")"
+
+      # SSH setup script goes here because windows XML parser sucks
+      cp ${autounattend.setupScript} pkgs/ssh-setup.ps1
+
       cp ${nuget} pkgs/bootstrap/00_"$(stripHash "${nuget}")"
       cp ${opensshutils} pkgs/bootstrap/01_"$(stripHash "${opensshutils}")"
       cp ${anaconda} pkgs/bootstrap/02_"$(stripHash "${anaconda}")"
@@ -133,7 +137,9 @@ let
         mkdir -p win
         mkdir -p win/nix-win
         7z x -y ${windowsIso} -owin
-        cp ${autounattend} win/autounattend.xml
+
+        cp ${autounattend.autounattendXML} win/autounattend.xml
+
         virt-make-fs --partition --type=fat win/ usbimage.img
         rm -rf win