Migrate AuthenticationController to CompatController

Convert `AuthenticationController` from the legacy Zend Controller to
`CompatController`, dropping `login.phtml` in favour of the new `LoginPage`
widget and `addContent()`. The view variable assignments are replaced by
`setTitle()` and `addContent(new LoginPage(...))`. Improve `httpBadRequest()`
message for external redirect attempts.

In `CompatController`, `$this->controls` is the tab bar area rendered
above the page content. When no tabs are added it still emits an empty
`<div class="controls">` wrapper. Setting `$this->view->compact = true`
suppresses that wrapper entirely, keeping the login page markup clean.

Handle the redirect on success in an `ON_SUBMIT` event handler. Delegate
the external-backend-only check to `LoginForm::onRequest()` via `ON_REQUEST`.
Use `$this->getServerRequest()` instead of `ServerRequest::fromGlobals()`.

Two structural fixes required by the changed DOM nesting:
- `login.less`: height `100%` -> `100vh` (`#login` is now inside `.content`
  which has no explicit height, so percentage inheritance breaks)
- `history.js`: `#layout > #login` -> `#layout #login` (direct-child selector
  breaks because `#login` is now a grandchild of `#layout` through `.content`)

application/controllers/AuthenticationController.php

@@ -5,7 +5,6 @@
 
 namespace Icinga\Controllers;
 
-use GuzzleHttp\Psr7\ServerRequest;
 use Icinga\Application\ClassLoader;
 use Icinga\Application\Hook\AuthenticationHook;
 use Icinga\Application\Hook\LoginButtonHook;
@@ -16,17 +15,20 @@ use Icinga\Authentication\LoginButtonForm;
 use Icinga\Common\Database;
 use Icinga\Exception\AuthenticationException;
 use Icinga\Forms\Authentication\LoginForm;
-use Icinga\Web\Controller;
 use Icinga\Web\Helper\CookieHelper;
 use Icinga\Web\RememberMe;
 use Icinga\Web\Url;
+use Icinga\Web\Widget\LoginPage;
+use ipl\Html\Contract\Form;
+use ipl\Web\Compat\CompatController;
+use Psr\Http\Message\ServerRequestInterface;
 use RuntimeException;
 use Throwable;
 
 /**
  * Application wide controller for authentication
  */
-class AuthenticationController extends Controller
+class AuthenticationController extends CompatController
 {
     use Database;
 
@@ -49,7 +51,17 @@ class AuthenticationController extends Controller
         if (($requiresSetup = $icinga->requiresSetup()) && $icinga->setupTokenExists()) {
             $this->redirectNow(Url::fromPath('setup'));
         }
-        $form = new LoginForm();
+
+        $form = (new LoginForm())
+            ->setAction(Url::fromRequest()->getAbsoluteUrl())
+            ->on(Form::ON_SUBMIT, function (LoginForm $form) {
+                if ($redirectUrl = $form->getRedirectUrl()) {
+                    $this->redirectNow($redirectUrl);
+                }
+            })
+            ->on(Form::ON_REQUEST, function (ServerRequestInterface $_, LoginForm $form) {
+                $form->onRequest();
+            });
 
         if (RememberMe::hasCookie() && $this->hasDb()) {
             $authenticated = false;
@@ -81,14 +93,16 @@ class AuthenticationController extends Controller
             if ($redirect) {
                 $redirectUrl = Url::fromPath($redirect, [], $this->getRequest());
                 if ($redirectUrl->isExternal()) {
-                    $this->httpBadRequest('nope');
+                    $this->httpBadRequest('Redirect to an external host is not allowed');
                 }
             } else {
-                $redirectUrl = $form->getRedirectUrl();
+                $redirectUrl = $form->createRedirectUrl();
             }
 
             $this->redirectNow($redirectUrl);
         }
+
+        $request = $this->getServerRequest();
         if (! $requiresSetup) {
             $cookies = new CookieHelper($this->getRequest());
             if (! $cookies->isSupported()) {
@@ -99,11 +113,10 @@ class AuthenticationController extends Controller
                     ->sendResponse();
                 exit;
             }
-            $form->handleRequest();
+            $form->handleRequest($request);
         }
 
         $loginButtons = [];
-        $request = ServerRequest::fromGlobals();
 
         foreach (LoginButtonHook::all() as $class => $hook) {
             try {
@@ -126,10 +139,10 @@ class AuthenticationController extends Controller
             }
         }
 
-        $this->view->form = $form;
-        $this->view->loginButtons = $loginButtons;
-        $this->view->defaultTitle = $this->translate('Icinga Web 2 Login');
-        $this->view->requiresSetup = $requiresSetup;
+        // Suppress the rendering of controls bar
+        $this->view->compact = true;
+        $this->setTitle($this->translate('Icinga Web 2 Login'));
+        $this->addContent(new LoginPage($form, $loginButtons, $requiresSetup));
     }
 
     /**

application/views/scripts/authentication/login.phtml

@@ -1,63 +0,0 @@
-<div id="login">
-    <div class="login-form" data-base-target="layout">
-        <div role="status" class="sr-only">
-            <?= $this->translate(
-                'Welcome to Icinga Web 2. For users of the screen reader Jaws full and expectant compliant'
-                . ' accessibility is possible only with use of the Firefox browser. VoiceOver on Mac OS X is tested on'
-                . ' Chrome, Safari and Firefox.'
-            ) ?>
-        </div>
-        <div class="logo-wrapper"><div id="icinga-logo" aria-hidden="true"></div></div>
-        <?php if ($requiresSetup): ?>
-            <p class="config-note"><?= sprintf(
-                $this->translate(
-                    'It appears that you did not configure Icinga Web 2 yet so it\'s not possible to log in without any defined '
-                    . 'authentication method. Please define a authentication method by following the instructions in the'
-                    . ' %1$sdocumentation%3$s or by using our %2$sweb-based setup-wizard%3$s.'
-                ),
-                '<a href="https://icinga.com/docs/icinga-web-2/latest/doc/05-Authentication/#authentication" title="'
-                    . $this->translate('Icinga Web 2 Documentation') . '">',
-                '<a href="' . $this->href('setup') . '" title="' . $this->translate('Icinga Web 2 Setup-Wizard') . '">',
-                '</a>'
-            ) ?></p>
-        <?php endif ?>
-        <?= $this->form ?>
-        <?= implode('', $this->loginButtons) ?>
-        <div id="login-footer">
-            <p>Icinga Web 2 &copy; 2013-<?= date('Y') ?></p>
-            <?= $this->qlink($this->translate('icinga.com'), 'https://icinga.com') ?>
-        </div>
-    </div>
-    <ul id="social">
-        <li>
-            <?= $this->qlink(
-                null,
-                'https://www.facebook.com/icinga',
-                null,
-                array(
-                    'target'  => '_blank',
-                    'icon'     => 'facebook-squared',
-                    'title'    => $this->translate('Icinga on Facebook')
-                )
-            ) ?>
-        </li>
-        <li><?= $this->qlink(
-                null,
-                'https://github.com/Icinga',
-                null,
-                array(
-                    'target'    => '_blank',
-                    'icon'      => 'github-circled',
-                    'title'     => $this->translate('Icinga on GitHub')
-                )
-            ) ?>
-        </li>
-    </ul>
-</div>
-<div id="orb-analytics" class="orb" ><?= $this->img('img/orb-analytics.png'); ?></div>
-<div id="orb-automation" class="orb"><?= $this->img('img/orb-automation.png'); ?></div>
-<div id="orb-cloud" class="orb"><?= $this->img('img/orb-cloud.png'); ?></div>
-<div id="orb-icinga" class="orb"><?= $this->img('img/orb-icinga.png'); ?></div>
-<div id="orb-infrastructure"  class="orb"><?= $this->img('img/orb-infrastructure.png'); ?></div>
-<div id="orb-metrics" class="orb" ><?= $this->img('img/orb-metrics.png'); ?></div>
-<div id="orb-notifactions" class="orb"><?= $this->img('img/orb-notifications.png'); ?></div>

public/css/icinga/login.less

@@ -4,7 +4,7 @@
 // Login page styles
 
 #login {
-  height: 100%;
+  height: 100vh;
   background-color: @menu-bg-color;
   background-image: url(../img/icingaweb2-background-orbs.jpg);
   background-repeat:  no-repeat;

public/js/icinga/history.js

@@ -230,7 +230,7 @@
         applyLocationBar: function (onload = false) {
             let col2State = this.getCol2State();
 
-            if (onload && document.querySelector('#layout > #login')) {
+            if (onload && document.querySelector('#layout #login')) {
                 // The user landed on the login
                 let redirectInput = document.querySelector('#login form input[name=redirect]');
                 redirectInput.value = redirectInput.value + col2State;