Handler.php

<?php

namespace LakeDrops\Docker4Drupal;

use Henrywhitaker3\Healthchecks\Exceptions\HealthchecksAccountLimitReachedException;
use Henrywhitaker3\Healthchecks\Exceptions\HealthchecksFailureException;
use Henrywhitaker3\Healthchecks\Exceptions\HealthchecksUnauthorisedException;
use Henrywhitaker3\Healthchecks\Exceptions\HealthchecksUuidNotFoundException;
use Henrywhitaker3\Healthchecks\Healthchecks;
use Henrywhitaker3\Healthchecks\HealthchecksManager;
use LakeDrops\Component\Composer\BaseHandler;
use LakeDrops\DockerTraefik\Traefik;
use LakeDrops\DrupalEnvironment\Handler as DrupalEnvironment;
use Symfony\Component\Filesystem\Filesystem;
use Symfony\Component\Yaml\Yaml;

/**
 * Class Handler.
 *
 * @package LakeDrops\Docker4Drupal
 */
class Handler extends BaseHandler {

  /**
   * {@inheritdoc}
   */
  public function configId(): string {
    return 'docker4drupal';
  }

  /**
   * {@inheritdoc}
   */
  protected function configDefault(): array {
    $dockerImageProxy = $this->env->receiveGlobal('docker_image_prefix', '', '');
    if (!empty($dockerImageProxy)) {
      $dockerImageProxy = str_replace('//', '/', $dockerImageProxy . '/');
    }
    $projectname = getenv('COMPOSE_PROJECT_NAME');
    if (empty($projectname)) {
      $projectname = str_replace([' ', '-', '_', '.'], '', basename(getcwd()));
      $this->env->put('COMPOSE_PROJECT_NAME', $projectname);
    }

    return [
      'docker_image_prefix' => $dockerImageProxy,
      'projectname' => $projectname,
      'staging' => FALSE,
      'basicauth' => [
        'enable' => FALSE,
        'user' => '',
        'pass' => '',
        'code' => '',
      ],
      'ci_home' => '/home/gitlab-runner',
      'docker0' => [
        'ip' => ($this->isCiContext() || $this->isLocalDevMode()) ?
          $this->getDockerGateway() :
          $this->getLocalIpv4('docker0'),
        'proxy' => ($this->isCiContext() || $this->isLocalDevMode()) ?
          $this->getDockerProxy() :
          FALSE,
      ],
      'traefik' => [
        'domain' => $this->env->receive('traefik_domain', '', 'docker.localhost'),
        'usessl' => $this->env->receive('traefik_usessl', '', '0'),
        'port' => $this->env->receive('traefik_port', '', '8000'),
        'ports' => $this->env->receive('traefik_ports', '', '8443'),
        'cert' => $this->env->receive('traefik_cert', '', 'fullchain.pem'),
        'key' => $this->env->receive('traefik_key', '', 'privkey.pem'),
        'portainer' => $this->env->receive('traefik_portainer', '', '0'),
        'hub_token' => $this->env->receive('traefik_hub_token', '', ''),
      ],
      'live' => [
        'root' => '',
        'uri' => '',
        'host' => '',
        'user' => $this->env->receive('live_host_username', 'Remote username for host of the live site', getenv('USER')),
      ],
      'drush' => [
        'sql' => [
          'tables' => [
            'structure' => [
              'cache',
              'cachetags',
              'cache_*',
              'history',
              'search_*',
              'sessions',
              'watchdog',
            ],
            'skip' => [
              'migration_*',
            ],
          ],
        ],
      ],
      'drupal' => [
        'version' => '9',
      ],
      'php' => [
        'version' => $this->env->receiveGlobal('PHP_VERSION', 'PHP version', '7.4'),
        'xdebug' => $this->env->receiveGlobal('PHP_DEBUG', 'PHP debug', '0'),
        'coverage' => $this->env->receiveGlobal('PHP_COVERAGE', 'PHP coverage', '0'),
        'related_subdomains' => [],
      ],
      'dbserver' => [
        'type' => 'mariadb',
        'version' => '10.6',
      ],
      'webserver' => [
        'type' => 'apache',
        'overwriteconfig' => FALSE,
      ],
      'mailhog' => [
        'enable' => 1,
        'host' => $this->env->receiveGlobal('MAILHOG_HOST', 'MailHog Host', 'smtp.freesmtpservers.com'),
        'port' => $this->env->receiveGlobal('MAILHOG_PORT', 'MailHog Port', '25'),
        'username' => $this->env->receiveGlobal('MAILHOG_USERNAME', 'MailHog Username'),
        'password' => $this->env->receiveGlobal('MAILHOG_PASSWORD', 'MailHog Password'),
        'mechanism' => $this->env->receiveGlobal('MAILHOG_MECHANISM', 'MailHog Auth Mechanism', 'NONE'),
      ],
      'varnish' => [
        'enable' => 0,
      ],
      'redis' => [
        'version' => '6',
      ],
      'dbbrowser' => [
        'type' => 'pma',
      ],
      'solr' => [
        'enable' => 0,
        'version' => '4.8.0',
      ],
      'node' => [
        'enable' => 0,
        'key' => '',
        'path' => '',
      ],
      'memcached' => [
        'enable' => 0,
      ],
      'rsyslog' => [
        'enable' => 0,
      ],
      'athenapdf' => [
        'enable' => 0,
        'key' => '',
      ],
      'blackfire' => [
        'enable' => 0,
        'id' => '',
        'token' => '',
      ],
      'webgrind' => [
        'enable' => 0,
      ],
      'selenium' => [
        'enable' => 0,
      ],
      'elasticsearch' => [
        'enable' => 0,
      ],
      'wkhtmltox' => [
        'enable' => 0,
      ],
      'backstop' => $this->backstopDefaults(),
      'crontabs' => [
        'www-data' => [],
      ],
      'backup' => [
        'enable' => FALSE,
        'version' => 'base-1.2.0-1.6.0',
        'crontime' => '50 */6 * * *',
        'crontimecheck' => '30 23 1 * *',
        'remoterepo' => FALSE,
        'retention' => [
          'hourly' => 2,
          'daily' => 7,
          'weekly' => 8,
          'monthly' => 12,
          'yearly' => 30,
        ],
      ],
    ];
  }

  /**
   * {@inheritdoc}
   */
  protected function postInit(): void {
    $this->env->put('PHP_VERSION', $this->config->readValue(['php', 'version']), TRUE);

    if ($this->isCiContext() || $this->isLocalDevMode()) {
      $projectRoot = $this->getDockerMountSource(getenv('CI_PROJECT_DIR'));
    }
    else {
      $projectRoot = getcwd();
    }
    $php = $this->config->readValue('php');
    $traefik = $this->config->readValue('traefik');

    // Check if SSH auth sockets are supported.
    $ssh_auth_sock = getenv('SSH_AUTH_SOCK');
    $php['ssh'] = !empty($ssh_auth_sock);
    if ($php['ssh']) {
      $php['ssh_auth_sock'] = ($this->isCiContext() || $this->isLocalDevMode()) ?
        $this->getDockerMountSource('/ssh-agent') :
        '$SSH_AUTH_SOCK';
    }
    $this->config->setValue('php', $php, FALSE);
    $this->config->setValue('projectroot', $projectRoot, FALSE);
    $this->config->setValue('projectdomain', $this->config->readValue('projectname') . '.' . $traefik['domain'], FALSE);
    $this->config->setValue('projectprotocol', 'http' . ($traefik['usessl'] ? 's' : ''), FALSE);
    $projectport = '';
    if ($traefik['usessl'] && (int) $traefik['ports'] !== 443) {
      $projectport = ':' . $traefik['ports'];
    }
    elseif (!$traefik['usessl'] && (int) $traefik['port'] !== 80) {
      $projectport = ':' . $traefik['port'];
    }
    $this->config->setValue('projectport', $projectport, FALSE);
    $relatedprojectdomains = [];
    foreach ($php['related_subdomains'] as $related_subdomain) {
      $relatedprojectdomains[] = $related_subdomain . '.' . $traefik['domain'];
    }
    $this->config->setValue('relatedprojectdomains', $relatedprojectdomains, FALSE);

    if ($alerta_api_key = getenv('ALERTA_APIKEY')) {
      $alerta = [
        'apikey' => $alerta_api_key,
      ];
      if ($value = getenv('ALERTA_ENVIRONMENT')) {
        $alerta['environment'] = $value;
      }
      if ($value = getenv('ALERTA_PROJECT_ID')) {
        $alerta['project_id'] = $value;
      }
      $this->config->setValue('alerta', $alerta, FALSE);
    }
  }

  /**
   * Configure Drupal Project for Docker.
   *
   * @param bool $overwrite
   *   Whether to overwrite existing config files.
   */
  public function configureProject(bool $overwrite = FALSE): void {

    // We only do the fancy stuff for developers.
    if (!$this->isDevMode()) {
      return;
    }

    $this->init();

    // Configure Drupal environment if avaiable.
    if ($this->getPackage('lakedrops/drupal-environment')) {
      $handler = new DrupalEnvironment($this->composer, $this->io);
      $handler->setupLakeDropsProject();

      // Update config for production build.
      if (getenv('LAKEDROPS_BUILD_NG') === 'yes') {
        $config = $handler->getConfig();
        $isStaging = !in_array(getenv('CI_COMMIT_REF_SLUG'), ['master', 'main'], TRUE);
        $root = '/drupal/' . getenv('CI_PROJECT_ID') . '/' . getenv('CI_COMMIT_BRANCH');
        $drupal = $this->config->readValue('drupal');
        $drupal['live'] = $config->readValue('live');
        $traefik = $this->config->readValue('traefik');
        $traefik['usessl'] = 1;
        $traefik['ports'] = 443;
        $crontabs = $this->config->readValue('crontabs');
        $crontabs['enable'] = (array_sum(array_map('count', $crontabs)) > 0);
        if (!$isStaging) {
          if ($this->config->readValue(['backup', 'enable'])) {
            $crontabs['borgmatic']['Backup'] = [
              'schedule' => $this->config->readValue(['backup', 'crontime']),
              'command' => 'backup',
            ];
            $crontabs['borgmatic']['Check backup'] = [
              'schedule' => $this->config->readValue(['backup', 'crontimecheck']),
              'command' => 'check',
            ];
          }
          $crontabs['www-data']['MySQL backup'] = [
            'schedule' => '5 0 * * *',
            'command' => 'cd /var/www/html && /usr/local/bin/drush sql:dump --result-file=/var/backups/mysql/drupal.sql',
          ];
          $crontabs['enable'] = TRUE;
          $crontabs['enable_mysql_backup'] = TRUE;
        }
        $this->config->setValue('crontabs', $crontabs, FALSE);
        $overwriteConfig = [
          'staging' => $isStaging,
          'docker0' => [
            'ip' => 'TRAEFIK-IP-PLACEHOLDER',
            'proxy' => 'TRAEFIK-IP-PLACEHOLDER',
          ],
          'drupal' => $drupal,
          'traefik' => $traefik,
          'projectroot' => $root . '/app',
          'projectrootbackup' => $root . '/backup',
          'projectrootdb' => $root . '/db',
          'projectrootfiles' => $root . '/files',
          'projectrootredis' => $root . '/redis',
          'projectname' => getenv('PROJECT_NAME') . '_' . getenv('CI_COMMIT_REF_SLUG'),
          'projectdomain' => $this->config->readValue('domain') ?? '',
          'projectprotocol' => 'https',
          'projectport' => '',
          'extradomains' => $this->config->readValue('aliases') ?? [],
        ];
        foreach ($overwriteConfig as $key => $value) {
          $this->config->setValue($key, $value, FALSE);
        }
      }
    }

    $fs = new Filesystem();
    $installationManager = $this->composer->getInstallationManager();

    $webRoot = $this->config->readValue('webroot');
    if ($webRoot !== NULL) {
      if (!$fs->exists($webRoot)) {
        return;
      }
    }
    else {
      $drupalCorePackage = $this->getDrupalCorePackage();
      if (!$drupalCorePackage) {
        // We are called too early, Drupal core is not available yet.
        return;
      }
      $corePath = $installationManager->getInstallPath($drupalCorePackage);
      // Directory where Drupal's index.php is located.
      $webRoot = dirname($corePath);
    }
    $this->config->setValue('webRoot', $webRoot, FALSE);

    // Directory where the root project is being created.
    $projectRoot = getcwd();
    // Directory where this plugin is being installed.
    $pluginRoot = $installationManager->getInstallPath($this->getPackage('lakedrops/docker4drupal'));

    // If the d8-project-scaffold or d9-project-scaffold  plugin is present we
    // only execute this one if $force is TRUE. This way we can make sure that
    // we get executed after d8-project-scaffold or d9-project-scaffold.
    $settingsPath = $webRoot . '/sites/default';
    if ($this->getPackage('lakedrops/d8-project-scaffold') ||
      $this->getPackage('lakedrops/d9-project-scaffold') ||
      $this->getPackage('lakedrops/drupal-environment') ||
      $this->getPackage('lakedrops/drupal-development-environment')) {
      if (!$fs->exists($projectRoot . '/settings/default')) {
        return;
      }
      $settingsPath = 'settings/default';
    }

    // Provide all the required files.
    $orig_ignored = FALSE;
    foreach ($this->getFiles($projectRoot, $webRoot, $settingsPath) as $template => $def) {
      if (isset($def['condition']) && !$def['condition']) {
        continue;
      }
      if (!$fs->exists($def['dest'])) {
        $fs->mkdir($def['dest']);
      }
      $filename = $this->config->render($template, $template);
      $file = $def['dest'] . '/' . $filename;
      if (!empty($def['delete'])) {
        if ($fs->exists($file)) {
          $fs->remove($file);
        }
        continue;
      }
      if (($overwrite && empty($def['add2git'])) || !$fs->exists($file)) {
        $source = isset($def['source']) && is_file($pluginRoot . '/templates/' . $def['source']) ?
          $pluginRoot . '/templates/' . $def['source'] :
          $pluginRoot . '/templates/' . ($def['source'] ?? '') . $template . '.twig';
        if (isset($def['options'])) {
          $this->config->setValue('loopoptions', $def['options'], FALSE);
        }
        $rendered = $this->config->render($filename, file_get_contents($source));
        $extraOptions = $this->config->readValue($filename);
        if (!empty($def['add2yaml']) && $extraOptions !== NULL) {
          $yaml = Yaml::parse($rendered);
          /** @noinspection SlowArrayOperationsInLoopInspection */
          $yaml = array_merge_recursive($yaml, $extraOptions);
          $rendered = Yaml::dump($yaml, 9, 2);

          // Render the string again so that custom content can also use variables
          $rendered = $this->config->render($filename, $rendered);
        }
        elseif ($extraOptions !== NULL) {
          $rendered .= $extraOptions;
        }
        if ($fs->exists($file)) {
          if (md5_file($file) === md5($rendered)) {
            continue;
          }
          $orig_file = $file . '.orig';
          if ($fs->exists($orig_file)) {
            $fs->remove($orig_file);
          }
          $fs->rename($file, $orig_file);
          if (!$orig_ignored) {
            $this->gitIgnore('*.orig');
            $orig_ignored = TRUE;
          }
        }
        if (empty($def['add2git'])) {
          $this->gitIgnore($filename);
        }
        file_put_contents($file, $rendered);
      }
      if (isset($def['link']) && ($def['link'] !== $settingsPath)) {
        $link = $def['link'] . '/' . $filename;
        if (!$fs->exists($link)) {
          $rel = substr($fs->makePathRelative($file, $projectRoot . '/' . $link), 3, -1);
          $fs->symlink($rel, $link);
        }
      }
      $fs->chmod($file, $def['mode'] ?? 0664);
    }

    // Make sure that settings.docker.php gets called from settings.php.
    $settingsPhpFile = $settingsPath . '/settings.php';
    if ($fs->exists($settingsPhpFile)) {
      $settingsPhp = file_get_contents($settingsPhpFile);
      if (strpos($settingsPhp, 'settings.docker.php') === FALSE) {
        $settingsPhp .= "\n\nif (file_exists(__DIR__ . '/settings.docker.php')) {\n  include __DIR__ . '/settings.docker.php';\n}\n";
        file_put_contents($settingsPhpFile, $settingsPhp);
      }
    }

    // Setup BackstopJS.
    $this->gitIgnore('tests/backstop/backstop.json');
    $this->gitIgnore('tests/backstop/backstop-script-*');
    $this->gitIgnore('tests/backstop/backstop_data/bitmaps_test');
    $this->gitIgnore('tests/backstop/backstop_data/html_report');
    $this->gitLFS('tests/backstop/**/*.png');

    if (getenv('LAKEDROPS_BUILD_NG') !== 'yes') {
      $this->updateTraefik();
    }

    // Set permissions, see https://wodby.com/stacks/drupal/docs/local/permissions
    exec('setfacl -dR -m u:$(whoami):rwX -m u:82:rwX -m u:100:rX -m g::rwX ' . $projectRoot . ' >/dev/null 2>&1');
    exec('setfacl -R -m u:$(whoami):rwX -m u:82:rwX -m u:100:rX -m g::rwX ' . $projectRoot . ' >/dev/null 2>&1');
  }

  /**
   * Configure Traefik on the host for all projects.
   */
  public function configureTraefik(): void {
    if (!$this->isDevMode()) {
      return;
    }
    $this->init();
    $this->updateTraefik();
  }

  /**
   * Update Traefik.
   */
  private function updateTraefik(): void {
    $traefik = new Traefik(
      $this->config->readValue('projectname'),
      $this->config->readValue(['traefik', 'domain']),
      $this->config->readValue(['traefik', 'port']),
      $this->config->readValue(['traefik', 'ports']),
      $this->config->readValue(['traefik', 'cert']),
      $this->config->readValue(['traefik', 'key'])
    );
    if ($this->config->readValue(['traefik', 'portainer'])) {
      $traefik->setAddonPortainer(TRUE);
    }
    if ($hub_token = $this->config->readValue(['traefik', 'hub_token'])) {
      $traefik->setHubToken($hub_token);
    }
    $traefik->update();
  }

  /**
   * List of files and settings on how to handle them.
   *
   * @param string $projectRoot
   *   Name of the project's root directory.
   * @param string $webRoot
   *   Name of the web's root directory.
   * @param string $settingsPath
   *   Name of the settings directory.
   *
   * @return array
   *   List of files.
   */
  protected function getFiles(string $projectRoot, string $webRoot, string $settingsPath): array {
    $files = [
      'settings.docker.php' => [
        'dest' => $projectRoot . '/' . $settingsPath,
        'link' => $webRoot . '/sites/default',
      ],
      'docker-compose.yml' => [
        'dest' => $projectRoot,
        'add2yaml' => TRUE,
      ],
      'drushrc.php' => [
        'dest' => $projectRoot . '/drush',
      ],
      'default.site.yml' => [
        'dest' => $projectRoot . '/drush/sites',
        'add2yaml' => TRUE,
      ],
      'stage.site.yml' => [
        'dest' => $projectRoot . '/drush/sites',
        'add2yaml' => TRUE,
      ],
      'drush.yml' => [
        'dest' => $projectRoot . '/drush',
        'add2yaml' => TRUE,
      ],
      'wkhtmltox.sh' => [
        'dest' => $projectRoot . '/.docker-init',
      ],
      'backstop.json' => [
        'source' => 'tests/backstop/',
        'dest' => $projectRoot . '/tests/backstop',
        'add2yaml' => TRUE,
      ],
      'backstop-script-before' => [
        'source' => 'tests/backstop/',
        'dest' => $projectRoot . '/tests/backstop',
        'add2yaml' => TRUE,
        'mode' => 0775,
      ],
      'backstop-script-after' => [
        'source' => 'tests/backstop/',
        'dest' => $projectRoot . '/tests/backstop',
        'add2yaml' => TRUE,
        'mode' => 0775,
      ],
      'vhost.conf' => [
        'dest' => $projectRoot . '/apache',
        'condition' => $this->config->readValue(['webserver', 'overwriteconfig']),
      ],
      'mhout.json' => [
        'dest' => $projectRoot . '/tests',
      ],
    ];
    if (getenv('LAKEDROPS_BUILD_NG') === 'yes') {
      if ($this->config->readValue(['backup', 'enable'])) {
        $files['config.yaml'] = [
          'source' => 'backup/',
          'dest' => $projectRoot . '/backup',
        ];
        $files['crontab.txt'] = [
          'source' => 'backup/',
          'dest' => $projectRoot . '/backup',
        ];
      }

      // Manage crontabs and optionally add them to heathcheck-io.
      $hj_url = getenv('HEALTHCHECK_URL');
      $hj_api_key = getenv('HEALTHCHECK_API_KEY');
      $hj_api_channels = getenv('HEALTHCHECK_API_CHANNELS');
      $hj_project = $this->config->readValue('projectname');
      $hj_branch = getenv('CI_COMMIT_BRANCH');
      $hj_timezone = $this->env->receiveGlobal('HEALTHCHECK_API_TIMEZONE', '', 'Europe/Berlin');
      $hj_checks = [];
      $hj_manager = NULL;

      if (!empty($hj_url) && !empty($hj_api_key)) {
        $hj_manager = new HealthchecksManager($hj_api_key, $hj_url . '/api/v1/');
        try {
          $hj_checks = $hj_manager->listChecks();
        }
        catch (HealthchecksFailureException | HealthchecksUnauthorisedException $e) {
          // Ignoring this for now.
        }
      }
      $activeTasks = [];
      foreach ($this->config->readValue('crontabs') ?? [] as $user => $tasks) {
        if (!is_array($tasks)) {
          continue;
        }
        foreach ($tasks as $name => $task) {
          $disabled = !empty($task['disabled']);
          $command = $task['command'];
          $schedule = $task['schedule'];
          $ping_url = FALSE;
          $task['name'] = $name;
          if (isset($hj_manager)) {
            unset($task['disabled'], $task['command']);
            $task['channels'] = $hj_api_channels;
            $task['tags'] = implode(' ', ['d4d', $hj_project, $hj_branch]);
            $task['tz'] = $hj_timezone;
            if (count(explode(' ', $task['schedule'])) === 6) {
              // Schedule contains seconds, they need to be removed.
              $task['schedule'] = substr($task['schedule'], strpos($task['schedule'], ' ') + 1);
            }

            $check = NULL;
            foreach ($hj_checks as $existing) {
              $tags = explode(' ', $existing['tags']);
              if ($task['name'] === $existing['name'] && in_array('d4d', $tags, TRUE) && in_array($hj_project, $tags, TRUE) && in_array($hj_branch, $tags, TRUE)) {
                $check = $existing;
                break;
              }
            }
            if (!$check) {
              if ($disabled) {
                // This task is disabled as it doesn't exist yet, nothing to do.
                continue;
              }
              try {
                $check = $hj_manager->createCheck($task);
                $parts = explode('/', $check['ping_url']);
                $uuid = array_pop($parts);
                $hj_check = new Healthchecks($uuid, $hj_url . '/ping/');
                $hj_check->success();
              }
              catch (HealthchecksFailureException | HealthchecksUuidNotFoundException | HealthchecksAccountLimitReachedException | HealthchecksUnauthorisedException $e) {
                // Ignoring this for now.
              }
            }
            else {
              $changed = FALSE;
              foreach ($task as $key => $value) {
                if (!isset($check[$key]) || $check[$key] !== $value) {
                  $changed = TRUE;
                }
              }
              if ($changed) {
                $parts = explode('/', $check['ping_url']);
                $uuid = array_pop($parts);
                try {
                  $check = $hj_manager->updateCheck($uuid, $task);
                }
                catch (HealthchecksFailureException | HealthchecksUuidNotFoundException | HealthchecksAccountLimitReachedException | HealthchecksUnauthorisedException $e) {
                  // Ignoring this for now.
                }
              }
            }
            if ($check) {
              $ping_url = $check['ping_url'];
            }
          }
          if (!$disabled) {
            if (count(explode(' ', $schedule)) === 5) {
              // Add leading "0" for seconds.
              $schedule = '0 ' . $schedule;
            }
            if ($user === 'borgmatic') {
              $backup = $this->config->readValue('backup');
              $backup['healthckeck_url'][$command] = $ping_url;
              $this->config->setValue('backup', $backup, FALSE);
            }
            else {
              $activeTasks[] = [
                'name' => $task['name'],
                'schedule' => $schedule,
                'command' => $command,
                'ping_url' => $ping_url,
                'user' => $user,
              ];
            }
          }
        }
        if (!empty($activeTasks)) {
          $files['jobs.ini'] = [
            'source' => 'crontabs/template.twig',
            'dest' => $projectRoot . '/crontabs',
            'options' => $activeTasks,
          ];
        }
      }
    }
    return $files;
  }

  /**
   * Determine local ipv4 address.
   *
   * @param string|null $interface
   *   The name of the interface for which to determine the ipv4 address.
   *
   * @return string|array
   *   The ipv4 address(es).
   */
  private function getLocalIpv4(string $interface = NULL) {
    $out = explode(PHP_EOL, shell_exec('LC_ALL=C /sbin/ifconfig'));
    $local_addrs = array();
    $ifname = 'unknown';
    foreach ($out as $str) {
      $matches = array();
      if (preg_match('/^([a-z0-9]+)(:\d{1,2})?(\s)+Link/', $str, $matches)) {
        $ifname = $matches[1];
        if ($matches[2] !== '') {
          $ifname .= $matches[2];
        }
      }
      elseif (preg_match('/inet addr:((?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:[.](?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3})\s/', $str, $matches)) {
        $local_addrs[$ifname] = $matches[1];
      }
    }

    if (!isset($interface)) {
      return $local_addrs;
    }
    return $local_addrs[$interface] ?? '127.0.0.1';
  }

  /**
   * @return string
   */
  private function getDockerGateway(): string {
    $container = $this->readContainerConfig();
    return $container['NetworkSettings']['Gateway'];
  }

  /**
   * @return string
   */
  private function getDockerProxy(): string {
    foreach ($this->readNetworkConfig()['Containers'] as $container) {
      if (isset($container['Name']) && in_array($container['Name'], ['traefik', 'traefik_traefik_1', 'traefik-traefik-1'])) {
        return explode('/', $container['IPv4Address'])[0];
      }
    }
    return '127.0.0.1';
  }

  /**
   * @param $projectRoot
   *
   * @return string
   */
  private function getDockerMountSource($projectRoot): string {
    $currentDir = getcwd();
    $container = $this->readContainerConfig();
    foreach ($container['Mounts'] as $mount) {
      if (empty($projectRoot)) {
        if ($currentDir === $mount['Destination']) {
          return $mount['Source'];
        }
      }
      else if (strpos($projectRoot, $mount['Destination']) === 0) {
        return $mount['Source'] . substr($projectRoot, strlen($mount['Destination']));
      }
    }
    return getcwd();
  }

  /**
   * @return array
   */
  private function readContainerConfig(): array {
    try {
      $output = [];
      exec('basename "$(cat /proc/1/cpuset)"', $output);
      $id = reset($output);
      if ($id === '/') {
        $id = getenv('COMPOSE_PROJECT_NAME') . '_l3d';
      }
      $output = [];
      exec('docker container inspect ' . $id, $output);
      return json_decode(implode('', $output), TRUE)[0];
    }
    catch (\Exception $ex) {
      // Ignore.
    }
    return [
      'NetworkSettings' => [
        'Gateway' => '127.0.0.1',
      ],
      'Mounts' => [],
    ];
  }

  /**
   * @return array
   */
  private function readNetworkConfig(): array {
    try {
      $output = [];
      exec('docker network inspect traefik-public', $output);
      return json_decode(implode('', $output), TRUE)[0];
    }
    catch (\Exception $ex) {
      // Ignore.
    }
    return [
      'Containers' => [],
    ];
  }

  /**
   * @return array
   */
  private function backstopDefaults(): array {
    return [
      'id' => 'drupal',
      'd4dscripts' => [
        'before' => [],
        'after' => [],
      ],
      'viewports' => [
        'desktop' => [
          'width' => 1960,
          'height' => 1280,
        ],
      ],
      'scenarios' => [
        'frontpage' => [
          'path' => '/',
        ],
      ],
    ];
  }

}