Add 'no_cache' route option to mark a route's responses as uncacheable (was: Cron run response should not be cacheable)

Makes sense to me, very good docs.

Does this mean that we no longer have to worry about the cron run in #2460911: Search reindexing should invalidate cache tags and keep that patch there shorter?

+++ b/core/modules/system/src/CronController.php
@@ -49,6 +63,11 @@ public static function create(ContainerInterface $container) {
+    // \Drupal\system\Access\CronAccessCheck only cares that the given cron key
+    // is correct; it may very well be triggered by anonymous users, which means
+    // that the page should never be cached.
+    $this->pageCacheKillSwitch->trigger();

Totally out of scope for this issue, but I wondered:

Will this also set the headers to private for non-page cache enabled so that reverse proxies don't cache it?

---

To the issue:

RTBC + 1

Trying to work on it.

We should make it possible to opt out on the routing level in the first place.

Looks fine.

Noticed the _csrf_token requirement in the admin cron route, makes me wonder if routes that have that shouldn't automatically get excluded from page cache as well. Also not quite sure what would happen if you have a link that anonymous users can access with _csrf_token ;)

1. +++ b/core/core.services.yml
   @@ -950,7 +956,7 @@ services:
   -    arguments: ['@language_manager', '@config.factory', '@page_cache_request_policy', '@page_cache_response_policy', '@cache_contexts']
   +    arguments: ['@language_manager', '@config.factory', '@page_cache_request_policy', '@page_cache_response_policy', '@cache_contexts', '@current_route_match', '@page_cache_kill_switch']
   

   This line is unfortunately superfluous now and not used.

2. +++ b/core/lib/Drupal/Core/EventSubscriber/FinishResponseSubscriber.php
   @@ -79,7 +79,7 @@ class FinishResponseSubscriber implements EventSubscriberInterface {
   -   *   The cache contexts service.
   +   *   The cache contexts
   

   This change looks unrelated and wrong?

As much as I dislike it: Back to CNW unfortunately ...

This looks great - thanks for the CR and Beta evaluation. Committed 144aa58 and pushed to 8.0.x. Thanks!

diff -u b/core/modules/user/src/Controller/UserController.php b/core/modules/user/src/Controller/UserController.php
--- b/core/modules/user/src/Controller/UserController.php
+++ b/core/modules/user/src/Controller/UserController.php
@@ -10,7 +10,6 @@
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\Datetime\DateFormatter;
-use Drupal\Core\PageCache\ResponsePolicy\KillSwitch;
 use Drupal\user\UserDataInterface;
 use Drupal\user\UserInterface;
 use Drupal\user\UserStorageInterface;
@@ -44,13 +43,6 @@
   protected $userData;
 
   /**
-   * The page cache killswitch.
-   *
-   * @var \Drupal\Core\PageCache\ResponsePolicy\KillSwitch
-   */
-  protected $pageCacheKillSwitch;
-
-  /**
    * Constructs a UserController object.
    *
    * @param \Drupal\Core\Datetime\DateFormatter $date_formatter
@@ -59,8 +51,6 @@
    *   The user storage.
    * @param \Drupal\user\UserDataInterface $user_data
    *   The user data service.
-   * @param \Drupal\Core\PageCache\ResponsePolicy\KillSwitch $page_cache_kill_switch
-   *   The page cache killswitch.
    */
   public function __construct(DateFormatter $date_formatter, UserStorageInterface $user_storage, UserDataInterface $user_data) {
     $this->dateFormatter = $date_formatter;

Did some more clean up on commit.

Love this. Great work!