Acquia cloud hook function to clear varnish cache.

clear_varnish.sh

#!/bin/bash

varnish_purge() {
  echo "@INFO: Clear varnish cache starting"

  for domain in `$drush_cmd ac-domain-list --format=print_r`; do
    echo "@INFO: Clearing varnish cache for $domain"
    $drush_cmd ac-domain-purge $domain
  done

  if [ $? -ne 0 ]; then
    echo "@INFO: Clear varnish cache errored"
    status=1
  else
    echo "@INFO: Clear varnish cache complete"
  fi
}