skip motd in UI if request initiated from tsh headless auth

web/packages/teleport/src/Login/Login.test.tsx

@@ -152,3 +152,26 @@ test('show login form after modt acknowledge', async () => {
   fireEvent.click(screen.getByText('Acknowledge'));
   expect(screen.getByPlaceholderText(/username/i)).toBeInTheDocument();
 });
+
+test('skip motd if login initiated from headless auth', async () => {
+  // set global window.location with redirect url.
+  global.window = Object.create(window);
+  const url =
+    'https://teleport.example.com/web/login?redirect_uri=https://teleport.example.com/web/headless/5c5c1f73-ac5c-52ee-bc9e-0353094dcb4a';
+  Object.defineProperty(window, 'location', {
+    value: {
+      href: url,
+    },
+  });
+
+  jest
+    .spyOn(cfg, 'getMotd')
+    .mockImplementation(
+      () => 'Welcome to cluster, your activity will be recorded.'
+    );
+  render(<Login />);
+
+  expect(
+    screen.queryByText('Welcome to cluster, your activity will be recorded.')
+  ).not.toBeInTheDocument();
+});

web/packages/teleport/src/Login/useLogin.ts

@@ -39,7 +39,16 @@ export default function useLogin() {
   const auth2faType = cfg.getAuth2faType();
   const isLocalAuthEnabled = cfg.getLocalAuthFlag();
   const motd = cfg.getMotd();
-  const [showMotd, setShowMotd] = useState(!!motd);
+  const [showMotd, setShowMotd] = useState(() => {
+    const url = new URL(window.location.href);
+    const redirect_uri = url.searchParams.get('redirect_uri');
+
+    if (redirect_uri?.includes('headless')) {
+      return false;
+    } else if (cfg.getMotd()) {
+      return true;
+    }
+  });
 
   function acknowledgeMotd() {
     setShowMotd(false);