Getting your local build policy into code.

Example Build Script

#!/usr/bin/env bash

# Pass all arguments to drush
while [ $# -gt 0 ]; do
  drush_flags="$drush_flags $1"
  shift
done

drush="drush $drush_flags"

build_path=$(dirname "$0")
drupal_path="/var/drupals/SITENAME/www"
file_lock_path="$drupal_path/.file_lock"

$drush sql-drop -y &&
$drush sqlc < $build_path/ref_db/SITE_db.sql -y
cd ~
$drush dl registry_rebuild -y
cd $drupal_path
$drush rr
echo "updatedb";
$drush updatedb -y
echo "clear cache";
$drush cc all
echo "Turn off caching";
$drush vset -y preprocess_css 0 &&
$drush vset -y preprocess_js 0 &&
echo "Enable Modules" &&
$drush en $(cat $build_path/mods_enabled | tr '\n' ' ') -y &&
echo "Disable Modules" &&
$drush dis $(cat $build_path/mods_purge | tr '\n' ' ') -y &&
echo "Uninstall Modules" &&
$drush pm-uninstall $(cat $build_path/mods_purge | tr '\n' ' ') -y &&
$drush cc all
$drush updatedb -y
$drush cc all
if test ! -e $file_lock_path && ! grep "~/.drush/aliases.drushrc.php" $file_lock_path && ! grep "~/.ssh/id_rsa" $file_lock_path; then
  if [[ ! -d ~/.drush ]]; then
    mkdir ~/.drush
  fi
  cp "$build_path/aliases.drushrc.php" ~/.drush &&
  cp "$build_path/id_rsa" ~/.ssh/id_rsa &&
  chmod 600 ~/.ssh/id_rsa &&
  echo "~/.drush/aliases.drushrc.php" >> $file_lock_path &&
  echo "~/.ssh/id_rsa" >> $file_lock_path
fi

if (test ! -e $file_lock_path && ! grep "$drupal_path/sites/default/files" $file_lock_path) || (test -e $file_lock_path && ! grep "$drupal_path/sites/default/files" $file_lock_path); then
  rm -rf $drupal_path/sites/default/files &&
  mkdir $drupal_path/sites/default/files &&
  chmod -R 775 $drupal_path/sites/default/files &&
  $drush rsync @SITE.prod:%files/ @self:$drupal_path/sites/default/files --delete &&
  echo "$drupal_path/sites/default/files" >> $file_lock_path
fi
echo "Revert Features" &&
$drush fra -y &&
$drush cc all
drush fra -y &&
$drush cc all