# OL means on line power. Anything else - OB (on battery), LB (low battery),
    # or no answer at all - is a failure worth waking up for, because the
    # hypervisor has a finite number of minutes left.
    local ups="{{ healthcheck_ups_name }}"
    local status charge runtime load

    status=$(upsc "${ups}@localhost" ups.status 2>/dev/null)
    if [ -z "$status" ]; then
        MESSAGE="cannot reach UPS ${ups} via upsd"
        return 1
    fi

    charge=$(upsc "${ups}@localhost" battery.charge 2>/dev/null)
    runtime=$(upsc "${ups}@localhost" battery.runtime 2>/dev/null)
    load=$(upsc "${ups}@localhost" ups.load 2>/dev/null)

    MESSAGE="status=${status} charge=${charge}% runtime=${runtime}s load=${load}%"
    [[ "$status" == *"OL"* ]]