Deployer script for locally-built composer-based Drupal 8 deployment. Drush heavily used, including sql-dump for backup.

deploy.php

<?php

/**
 * @file
 * Deployment script for composer-based Drupal 8 installations using Deployer.
 */

namespace Deployer;

use Deployer\Support\Unix;

require 'recipe/common.php';

// Project name.
set('application', 'your_project_name');

// Project repository.
set('repository', 'file://' . __DIR__ . '/.git');

// Local build path.
set('local_build_path', Unix::parseHomeDir('~') . "/.deployer/build/{{application}}");

set('writable_mode', 'chmod');

// Releases to keep.
set('keep_releases', 3);

set('allow_anonymous_stats', FALSE);

// Hosts.
host('example.com')
  ->user('your_user')
  ->port(2220)
  ->identityFile('~/.ssh/your_identity_file')
  ->forwardAgent(TRUE)
  ->multiplexing(TRUE)
  ->set('deploy_path', '~/httpdocs');

// Drupal settings.
// Set drupal site. Change if you use different site.
set('drupal_site', 'default');
// Drupal 8 shared dirs.
set('shared_dirs', [
  'web/sites/{{drupal_site}}/files',
  'web/sites/{{drupal_site}}/private',
  'web/libraries',
]);
// Drupal 8 shared files.
set('shared_files', [
  'web/sites/{{drupal_site}}/settings.local.php',
  'web/sites/{{drupal_site}}/settings.php',
  'web/sites/{{drupal_site}}/services.yml',
]);
// Drupal 8 Writable dirs.
set('writable_dirs', [
  'web/sites/{{drupal_site}}/files',
]);

// Build the code locally.
task('build', function () {
  set('deploy_path', "{{local_build_path}}");
  invoke('deploy:prepare');
  invoke('deploy:release');
  invoke('deploy:update_code');
  invoke('deploy:vendors');
  invoke('deploy:symlink');
})->local();

// Upload the code with rsync (built-in Deployer upload function).
task('upload', function () {
  upload("{{local_build_path}}/current/", '{{release_path}}', [
    'options' => [
      "--exclude '.git'",
    ],
  ]);
});

// Drush commands to finalize the deployment.
set('php_bin_path', '/usr/bin/env php');
set('drush_bin_path', '{{deploy_path}}/current/vendor/bin/drush');
set('drush_command', '{{php_bin_path}} -d memory_limit=512M {{drush_bin_path}}');
set('drush_sql_dump_args', 'sql-dump --gzip --result-file={{application}}-sql-dump.sql');
if (has('previous_release')) {
  set('drush_sql_dump_args', 'sql-dump --gzip --result-file={{previous_release}}/{{application}}-sql-dump.sql');
}
task('drush:prepare', function () {
  run('{{drush_command}} cc drush');
  run('{{drush_command}} cr');
  run('{{drush_command}} {{drush_sql_dump_args}}');
});
task('drush:update', function () {
  run('{{drush_command}} sset system.maintenance_mode 1');
  run('{{drush_command}} updatedb -y');
  run('{{drush_command}} config-import -y');
  run('{{drush_command}} updatedb -y');
  run('{{drush_command}} cr');
  run('{{drush_command}} sset system.maintenance_mode 0');
});

// The deploy task. Based on the built-in drupal8 recipe.
// @see recipe/drupal8.php
task('deploy', [
  'build',
  'deploy:info',
  'deploy:prepare',
  'deploy:lock',
  'deploy:release',
  'upload',
  'drush:prepare',
  'deploy:shared',
  'deploy:writable',
  'deploy:symlink',
  'drush:update',
  'deploy:unlock',
  'cleanup',
]);

task('drush:maintenance:disable', function () {
  run('{{drush_command}} sset system.maintenance_mode 0');
});

// [Optional] if deploy fails automatically unlock.
after('deploy:failed', 'deploy:unlock');
after('deploy:failed', 'drush:maintenance:disable');

after('deploy', 'success');