development.services.yml

# Local development services.
#
# To activate this feature, follow the instructions at the top of the
# 'example.settings.local.php' file, which sits next to this file.
parameters:
  http.response.debug_cacheability_headers: true
services:
  cache.backend.null:
    class: Drupal\Core\Cache\NullBackendFactory
parameters:
  twig.config:
    debug: true
    auto_reload: true
    cache: false

response-headers.txt

HTTP/1.1 200 OK
Date: Thu, 19 Oct 2017 17:16:45 GMT
Server: Apache/2.4.10 (Debian)
X-Powered-By: PHP/7.1.10
Cache-Control: must-revalidate, no-cache, private
X-Drupal-Dynamic-Cache: MISS
X-UA-Compatible: IE=edge
Content-language: en
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-Drupal-Cache-Tags: block_view config:block.block.participatory_budget_admin config:block.block.participatory_budget_branding config:block.block.participatory_budget_local_actions config:block.block.participatory_budget_local_tasks config:block.block.participatory_budget_login config:block.block.participatory_budget_messages config:block.block.participatory_budget_page_title config:block.block.participatory_budget_tools config:block_list config:system.menu.admin config:system.menu.tools config:system.site config:user.role.anonymous config:user.settings http_response rendered
X-Drupal-Cache-Contexts: languages:language_interface route theme url.path url.query_args user.permissions user.roles:authenticated
Expires: Sun, 19 Nov 1978 05:00:00 GMT
X-Generator: Drupal 8 (https://www.drupal.org)
X-Drupal-Cache: HIT
Content-Type: text/html; charset=UTF-8

settings.local.php

<?php

/**
 * @file
 * Local development override configuration feature.
 *
 * To activate this feature, copy and rename it such that its path plus
 * filename is 'sites/default/settings.local.php'. Then, go to the bottom of
 * 'sites/default/settings.php' and uncomment the commented lines that mention
 * 'settings.local.php'.
 *
 * If you are using a site name in the path, such as 'sites/example.com', copy
 * this file to 'sites/example.com/settings.local.php', and uncomment the lines
 * at the bottom of 'sites/example.com/settings.php'.
 */

/**
 * Assertions.
 *
 * The Drupal project primarily uses runtime assertions to enforce the
 * expectations of the API by failing when incorrect calls are made by code
 * under development.
 *
 * @see http://php.net/assert
 * @see https://www.drupal.org/node/2492225
 *
 * If you are using PHP 7.0 it is strongly recommended that you set
 * zend.assertions=1 in the PHP.ini file (It cannot be changed from .htaccess
 * or runtime) on development machines and to 0 in production.
 *
 * @see https://wiki.php.net/rfc/expectations
 */
assert_options(ASSERT_ACTIVE, TRUE);
\Drupal\Component\Assertion\Handle::register();

/**
 * Enable local development services.
 */
$settings['container_yamls'][] = DRUPAL_ROOT . '/sites/development.services.yml';

/**
 * Show all error messages, with backtrace information.
 *
 * In case the error level could not be fetched from the database, as for
 * example the database connection failed, we rely only on this value.
 */
$config['system.logging']['error_level'] = 'verbose';

/**
 * Disable CSS and JS aggregation.
 */
$config['system.performance']['css']['preprocess'] = FALSE;
$config['system.performance']['js']['preprocess'] = FALSE;

/**
 * Disable the render cache (this includes the page cache).
 *
 * Note: you should test with the render cache enabled, to ensure the correct
 * cacheability metadata is present. However, in the early stages of
 * development, you may want to disable it.
 *
 * This setting disables the render cache by using the Null cache back-end
 * defined by the development.services.yml file above.
 *
 * Do not use this setting until after the site is installed.
 */
$settings['cache']['bins']['render'] = 'cache.backend.null';

/**
 * Disable caching for migrations.
 *
 * Uncomment the code below to only store migrations in memory and not in the
 * database. This makes it easier to develop custom migrations.
 */
# $settings['cache']['bins']['discovery_migration'] = 'cache.backend.memory';

/**
 * Disable Dynamic Page Cache.
 *
 * Note: you should test with Dynamic Page Cache enabled, to ensure the correct
 * cacheability metadata is present (and hence the expected behavior). However,
 * in the early stages of development, you may want to disable it.
 */
$settings['cache']['bins']['dynamic_page_cache'] = 'cache.backend.null';

/**
 * Allow test modules and themes to be installed.
 *
 * Drupal ignores test modules and themes by default for performance reasons.
 * During development it can be useful to install test extensions for debugging
 * purposes.
 */
$settings['extension_discovery_scan_tests'] = TRUE;

/**
 * Enable access to rebuild.php.
 *
 * This setting can be enabled to allow Drupal's php and database cached
 * storage to be cleared via the rebuild.php page. Access to this page can also
 * be gained by generating a query string from rebuild_token_calculator.sh and
 * using these parameters in a request to rebuild.php.
 */
$settings['rebuild_access'] = TRUE;

/**
 * Skip file system permissions hardening.
 *
 * The system module will periodically check the permissions of your site's
 * site directory to ensure that it is not writable by the website user. For
 * sites that are managed with a version control system, this can cause problems
 * when files in that directory such as settings.php are updated, because the
 * user pulling in the changes won't have permissions to modify files in the
 * directory.
 */
$settings['skip_permissions_hardening'] = TRUE;

settings.php

<?php

/**
 * Load services definition file.
 */
$settings['container_yamls'][] = __DIR__ . '/services.yml';

/**
 * Include the Pantheon-specific settings file.
 *
 * n.b. The settings.pantheon.php file makes some changes
 *      that affect all envrionments that this site
 *      exists in.  Always include this file, even in
 *      a local development environment, to insure that
 *      the site settings remain consistent.
 */
include __DIR__ . "/settings.pantheon.php";

/**
 * If there is a local settings file, then include it
 */
$local_settings = __DIR__ . "/settings.local.php";
if (file_exists($local_settings)) {
  include $local_settings;
}