drush_deploy.sh

# Completely flush redis, old stuff is no longer relevant and wastes space, avoids any 
# old state to influence update functions.
./vendor/bin/drush ev "\Drupal::service('redis.factory')->getClient()->flushAll()"
# Check if there are any updates to run.
if [ -n "$(./vendor/bin/drush updbst --format=list 2>/dev/null)" ]; then
  # If so, then drush updb includes a drush cr, but separately clear css/js cache
  # because due to memory cache backend during updates, it does not invalidate things properly.
  ./vendor/bin/drush updb -y
  ./vendor/bin/drush cc css-js
else
  # If not then just rebuild specific things that are not in redis like routes and aggregated files.
  ./vendor/bin/drush cc router
  ./vendor/bin/drush cc render
  ./vendor/bin/drush cc css-js
fi