Add system-wide settings config for administrators (#3498)

Co-authored-by: Jack Wotherspoon <jackwoth@google.com>

packages/cli/src/config/settings.ts

@@ -6,7 +6,7 @@
 
 import * as fs from 'fs';
 import * as path from 'path';
-import { homedir } from 'os';
+import { homedir, platform } from 'os';
 import * as dotenv from 'dotenv';
 import {
   MCPServerConfig,
@@ -24,9 +24,22 @@ export const SETTINGS_DIRECTORY_NAME = '.gemini';
 export const USER_SETTINGS_DIR = path.join(homedir(), SETTINGS_DIRECTORY_NAME);
 export const USER_SETTINGS_PATH = path.join(USER_SETTINGS_DIR, 'settings.json');
 
+function getSystemSettingsPath(): string {
+  if (platform() === 'darwin') {
+    return '/Library/Application Support/GeminiCli/settings.json';
+  } else if (platform() === 'win32') {
+    return 'C:\\ProgramData\\gemini-cli\\settings.json';
+  } else {
+    return '/etc/gemini-cli/settings.json';
+  }
+}
+
+export const SYSTEM_SETTINGS_PATH = getSystemSettingsPath();
+
 export enum SettingScope {
   User = 'User',
   Workspace = 'Workspace',
+  System = 'System',
 }
 
 export interface CheckpointingSettings {
@@ -81,16 +94,19 @@ export interface SettingsFile {
 }
 export class LoadedSettings {
   constructor(
+    system: SettingsFile,
     user: SettingsFile,
     workspace: SettingsFile,
     errors: SettingsError[],
   ) {
+    this.system = system;
     this.user = user;
     this.workspace = workspace;
     this.errors = errors;
     this._merged = this.computeMergedSettings();
   }
 
+  readonly system: SettingsFile;
   readonly user: SettingsFile;
   readonly workspace: SettingsFile;
   readonly errors: SettingsError[];
@@ -105,6 +121,7 @@ export class LoadedSettings {
     return {
       ...this.user.settings,
       ...this.workspace.settings,
+      ...this.system.settings,
     };
   }
 
@@ -114,6 +131,8 @@ export class LoadedSettings {
         return this.user;
       case SettingScope.Workspace:
         return this.workspace;
+      case SettingScope.System:
+        return this.system;
       default:
         throw new Error(`Invalid scope: ${scope}`);
     }
@@ -243,10 +262,27 @@ export function loadEnvironment(): void {
  */
 export function loadSettings(workspaceDir: string): LoadedSettings {
   loadEnvironment();
+  let systemSettings: Settings = {};
   let userSettings: Settings = {};
   let workspaceSettings: Settings = {};
   const settingsErrors: SettingsError[] = [];
 
+  // Load system settings
+  try {
+    if (fs.existsSync(SYSTEM_SETTINGS_PATH)) {
+      const systemContent = fs.readFileSync(SYSTEM_SETTINGS_PATH, 'utf-8');
+      const parsedSystemSettings = JSON.parse(
+        stripJsonComments(systemContent),
+      ) as Settings;
+      systemSettings = resolveEnvVarsInObject(parsedSystemSettings);
+    }
+  } catch (error: unknown) {
+    settingsErrors.push({
+      message: getErrorMessage(error),
+      path: SYSTEM_SETTINGS_PATH,
+    });
+  }
+
   // Load user settings
   try {
     if (fs.existsSync(USER_SETTINGS_PATH)) {
@@ -300,6 +336,10 @@ export function loadSettings(workspaceDir: string): LoadedSettings {
   }
 
   return new LoadedSettings(
+    {
+      path: SYSTEM_SETTINGS_PATH,
+      settings: systemSettings,
+    },
     {
       path: USER_SETTINGS_PATH,
       settings: userSettings,