Added some hooks to integrate with CERN requirements.

cern_integration.module

 <?php
 
-function cern_integration_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
-   drupal_set_message(t("Form ID: $form_id"), "status");
-}
+//function cern_integration_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
+   //drupal_set_message(t("Form ID: $form_id"), "status");
+//}
 
 /**
  * Implements hook_update_projects_alter().
@@ -31,3 +31,177 @@ function cern_integration_update_projects_alter(&$projects)
         }
     }
 }
+
+/**
+* Implements hook_form_FORM_ID_alter() for views_exposed_form().
+*/
+function cern_integration_form_views_exposed_form_alter(&$form, &$form_state, $form_id){
+    //dpm($form);
+    //drupal_set_message(t("VIEWS Exposed Form ID: $form_id"), "status");
+}
+
+#################
+# People        #
+# /admin/people #
+#################
+
+/**
+* Implements hook_form_FORM_ID_alter() for views_form_user_admin_people_page_1().
+* Remove actions and headers related to user settings.
+*/
+function cern_integration_form_views_form_user_admin_people_page_1_alter(&$form, &$form_state, $form_id){
+    $form['actions']['#disabled'] = TRUE;
+    $form['header']['#disabled'] = TRUE;
+
+    $txt = '<b>Actions concerning user accounts/roles are <em>DISABLED:</em></b><br/>All accounts are centrally managed at CERN via the portal at <a href="http://cern.ch/account">http://cern.ch/account</a> for accounts and passwords, and user roles through e-groups at <a href="http://e-groups.cern.ch">http://e-groups.cern.ch</a>';
+    $form['header']['#prefix'] = t($txt);
+}
+
+/**
+*  Implements hook_form_FORM_ID_alter() for user_register_form().
+*  Disable fields under admin/people/create
+*/
+function cern_integration_form_user_register_form_alter(&$form, &$form_state, $form_id){
+    drupal_set_message(t("Adding/Removing users is DISABLED."),"warning");    
+    // Disable all elements from this form.
+    foreach (\Drupal\Core\Render\Element::children($form) as $key) {
+        $form[$key]['#disabled'] = TRUE;
+    }
+}
+
+/**
+* Implements hook_module_implements_alter().
+* @see https://cgit.drupalcode.org/simplesamlphp_auth/tree/simplesamlphp_auth.module
+* @see cern_integration_form_user_form_alter(&$form, &$form_state, $form_id)
+* As this module injects a checkbox on user_form, cern_integration module must be unstacked.
+*/
+function cern_integration_module_implements_alter(&$implementations, $hook) {    
+  if ($hook == 'form_alter') {    
+    // Move my_module_form_alter() to the end of the list.
+    // \Drupal::moduleHandler()->getImplementations()
+    // iterates through $implementations with a foreach loop which PHP iterates
+    // in the order that the items were added, so to move an item to the end of
+    // the array, we remove it and then add it.
+    $group = $implementations['cern_integration'];
+    unset($implementations['cern_integration']);
+    $implementations['cern_integration'] = $group;
+  }
+}
+
+/*
+*  Implements hook_form_FORM_ID_alter() for user_form().
+*  Disable fields under admin/people -> Edit username
+*  @see /user/<id>/edit?destination=/admin/people
+*/
+function cern_integration_form_user_form_alter(&$form, &$form_state, $form_id){    
+    $form['account']['mail']['#disabled'] = TRUE;
+    $form['account']['name']['#disabled'] = TRUE;
+    $form['account']['pass']['#disabled'] = TRUE;
+    $form['account']['current_pass']['#disabled'] = TRUE;
+    $form['account']['status']['#disabled'] = TRUE;
+    $form['account']['roles']['#disabled'] = TRUE;
+
+    // This comes from cern_integration_module_implements_alter, executing the module to the last.
+    $form['simplesamlphp_auth_user_enable']['#disabled'] = TRUE;
+
+    unset($form['actions']['delete']);
+}
+
+################################
+# Account settings             #
+# admin/config/people/accounts #
+################################
+/**
+*  Implements hook_form_FORM_ID_alter() for user_admin_settings().
+* @see /admin/config/people/accounts
+*/
+function cern_integration_form_user_admin_settings_alter(&$form, &$form_state, $form_id){    
+    $form['registration_cancellation']['#disabled'] = TRUE;
+    $txt = '<b>Changing registration and cancellation settings is <em>DISABLED:</em></b><br/>All accounts are centrally managed at CERN via the portal at <a href="http://cern.ch/account">http://cern.ch/account</a> for accounts and passwords, and user roles through e-groups at <a href="http://e-groups.cern.ch">http://e-groups.cern.ch</a>';    
+    $form['registration_cancellation']['#prefix'] = t($txt);
+}
+
+###########################################
+# SimpleSAMLphp Auth                      #
+# /admin/config/people/simplesamlphp_auth #
+###########################################
+/**
+*  Implements hook_form_FORM_ID_alter() for simplesamlphp_auth_basic_settings_form().
+* @see /admin/config/people/simplesamlphp_auth
+*/
+function cern_integration_form_simplesamlphp_auth_basic_settings_form_alter(&$form, &$form_state, $form_id){    
+    $form['basic']['activate']['#disabled'] = TRUE;
+    $form['basic']['auth_source']['#disabled'] = TRUE;
+    $form['basic']['login_link_display_name']['#disabled'] = TRUE;
+
+    $form['user_provisioning']['register_users']['#disabled'] = TRUE;    
+}
+
+/**
+*  Implements hook_form_FORM_ID_alter() simplesamlphp_auth_local_settings_form().
+* @see /admin/config/people/simplesamlphp_auth/local
+*/
+function cern_integration_form_simplesamlphp_auth_local_settings_form_alter(&$form, &$form_state, $form_id){    
+    $form['authentication']['allow_default_login']['#disabled'] = TRUE;
+    $form['authentication']['allow_set_drupal_pwd']['#disabled'] = TRUE;
+    $form['authentication']['allow_default_login_roles']['#disabled'] = TRUE;
+    $form['authentication']['allow_default_login_users']['#disabled'] = TRUE;
+}
+
+/**
+*  Implements hook_form_FORM_ID_alter() simplesamlphp_auth_syncing_settings_form().
+* @see /admin/config/people/simplesamlphp_auth/sync
+*/
+function cern_integration_form_simplesamlphp_auth_syncing_settings_form_alter(&$form, &$form_state, $form_id){    
+    $form['user_info']['unique_id']['#disabled'] = TRUE;
+    $form['user_info']['user_name']['#disabled'] = TRUE;
+    $form['user_info']['user_name_sync']['#disabled'] = TRUE;
+    $form['user_info']['mail_attr']['#disabled'] = TRUE;
+    $form['user_info']['mail_attr_sync']['#disabled'] = TRUE;
+    $form['user_info']['mail_attr_sync']['#disabled'] = TRUE;
+    $form['user_info']['role_eval_every_time']['#disabled'] = TRUE;
+    $form['user_info']['autoenablesaml']['#disabled'] = TRUE;
+}
+
+###############################
+# Piwik                       #
+# /admin/config/system/piwik  #
+###############################
+/**
+*  Implements hook_form_FORM_ID_alter() for piwik_admin_settings().
+* @see /admin/config/system/piwik
+*/
+function cern_integration_form_piwik_admin_settings_alter(&$form, &$form_state, $form_id){    
+    $form['general']['piwik_site_id']['#disabled'] = TRUE;
+    $form['general']['piwik_url_http']['#disabled'] = TRUE;
+    $form['general']['piwik_url_https']['#disabled'] = TRUE;
+
+    global $base_url;
+    $_finalurl = $base_url;
+    $_searches = array("http://","https://",".web.cern.ch");
+    $_finalurl = str_replace($_searches, "", $_finalurl);        
+
+    $form['cern_view_statistics'] = array(
+        '#type' => 'fieldset',
+        '#title' => t('View statistics'),
+        '#weight' => - 30
+    );
+
+    $_markup = \Drupal\Core\Link::fromTextAndUrl('WebServices website', \Drupal\Core\Url::fromUri("https://webservices.web.cern.ch/webservices/Tools/Piwik/?SiteName=$_finalurl"))->toString();
+    $form['cern_view_statistics']['piwik_link'] = array(
+        '#markup' => "Please go to " . $_markup . " to view statistics gathered by Piwik for your site."
+    );   
+}
+
+######################################
+# Logging and errors                 #
+# /admin/config/development/logging  #
+######################################
+/**
+*  Implements hook_form_FORM_ID_alter() for system_logging_settings().
+* @see /admin/config/development/logging
+*/
+function cern_integration_form_system_logging_settings_alter(&$form, &$form_state, $form_id){
+    $form['syslog_identity']['#disabled'] = TRUE;
+    $form['syslog_facility']['#disabled'] = TRUE;    
+}
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