fix vscode remote support

Signed-off-by: Xe <me@christine.website>

common/home-manager/default.nix

@@ -20,6 +20,7 @@
 
     # implicit
     ./pastebins
+    ./vscode-remote
   ];
 
   nixpkgs.config = {

common/home-manager/vscode-remote/default.nix

@@ -0,0 +1,15 @@
+import ./module.nix ({ name, description, serviceConfig }:
+
+{
+  systemd.user.services.${name} = {
+    Unit = {
+      Description = description;
+    };
+
+    Service = serviceConfig;
+
+    Install = {
+      WantedBy = [ "default.target" ];
+    };
+  };
+})

common/home-manager/vscode-remote/module.nix

@@ -0,0 +1,49 @@
+moduleConfig:
+{ lib, pkgs, ... }:
+
+with lib;
+
+{
+  options.services.vscode-server.enable = with types; mkEnableOption "VS Code Server";
+
+  config = moduleConfig rec {
+    name = "auto-fix-vscode-server";
+    description = "Automatically fix the VS Code server used by the remote SSH extension";
+    serviceConfig = {
+      # When a monitored directory is deleted, it will stop being monitored.
+      # Even if it is later recreated it will not restart monitoring it.
+      # Unfortunately the monitor does not kill itself when it stops monitoring,
+      # so rather than creating our own restart mechanism, we leverage systemd to do this for us.
+      Restart = "always";
+      RestartSec = 0;
+      ExecStart = "${pkgs.writeShellScript "${name}.sh" ''
+        set -euo pipefail
+        PATH=${makeBinPath (with pkgs; [ coreutils findutils inotify-tools ])}
+        bin_dir=~/.vscode-server/bin
+
+        # Fix any existing symlinks before we enter the inotify loop.
+        if [[ -e $bin_dir ]]; then
+          find "$bin_dir" -mindepth 2 -maxdepth 2 -name node -exec ln -sfT ${pkgs.nodejs-16_x}/bin/node {} \;
+          find "$bin_dir" -path '*/@vscode/ripgrep/bin/rg' -exec ln -sfT ${pkgs.ripgrep}/bin/rg {} \;
+        else
+          mkdir -p "$bin_dir"
+        fi
+
+        while IFS=: read -r bin_dir event; do
+          # A new version of the VS Code Server is being created.
+          if [[ $event == 'CREATE,ISDIR' ]]; then
+            # Create a trigger to know when their node is being created and replace it for our symlink.
+            touch "$bin_dir/node"
+            inotifywait -qq -e DELETE_SELF "$bin_dir/node"
+            ln -sfT ${pkgs.nodejs-16_x}/bin/node "$bin_dir/node"
+            ln -sfT ${pkgs.ripgrep}/bin/rg "$bin_dir/node_modules/@vscode/ripgrep/bin/rg"
+          # The monitored directory is deleted, e.g. when "Uninstall VS Code Server from Host" has been run.
+          elif [[ $event == DELETE_SELF ]]; then
+            # See the comments above Restart in the service config.
+            exit 0
+          fi
+        done < <(inotifywait -q -m -e CREATE,ISDIR -e DELETE_SELF --format '%w%f:%e' "$bin_dir")
+      ''}";
+    };
+  };
+}