# $Id$ PyKota - Print Quota for CUPS (c) 2003 Jerome Alet This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. ==================================================================== READ SPECIAL LICENSING AND REDISTRBUTION TERMS IN THE FILE 'LICENSE' ==================================================================== PyKota is a complete Print Quota system for the Common Unix Printing System (aka CUPS), which works by directly querying the printers for the number of pages they have printed. Actual working features : - Per printer user quotas. - Automated email warning of users above quota to the user himself and to the print quota administrator. - CUPS filter for quota accounting : pykota - Command line print quota editor : edpykota - Command line print quota report generator : repykota - Command line print quota automated warning sender : warnpykota - Command line tools mimic the disk quota utilities for easier mastering. - Centralized storage of quotas : you can manage quotas for different printers on different print servers and store them all on the same quota storage server. WARNING : actually all your printers must have an unique name, but this may change in a future version. - SNMP querying of any networked SNMP-enabled printer. - External command querying of any printer : you can use you own querying command, e.g. to query a printer via the serial port, sending it a special PJL job and reading the result. See the example scripts in the "untested" directory and try to adapt them to your configuration. - Special scripts included for a seamless integration of PyKota on Debian machines. - Complete job history is saved. This will allow more complex reports in the future. All the command line tools accept the -h | --help command line option which prints all the available options and show usage examples. Planned features are described in the TODO file. Actually only the lazy quota method is implemented. What do I call lazy method ? The lazy method consists in querying the printer (actually via SNMP) for its total pages counter, just before the beginning of a job, and use this to modify the *preceding* user's quota. So you're always late of one print job, but this is generally ok, especially because a check is also done to see if the current user is allowed or not to print. Problem may theorically arise in batches of successive print jobs by different users when there's no sleep time between two jobs : the used pages may theorically be attributed to an incorrect user in the case that the printer is asked for its page counter at the beginning of a new job and before the end of the previous job. This depends on the printer speed and time between jobs, but so far I've not seen any problem with moderately used printers. This also depends on CUPS internal behavior : if CUPS doesn't begin to send a job to a printer before the previous one is completely printed, then there's no problem. Other querying methods which won't suffer from this possible problem, but probably from other ones ;-) will be implemented in the future. PyKota is known to work fine with HP Laserjet 2100 and 2200 networked printers, and should work with any SNMP-enabled network printer capable of outputing its lifetime printed pages number. If your printers don't support SNMP, then making them work with PyKota is up to you. Some sample scripts which can query non-SNMP printers for their lifetime page counter are included in the ./untested directory. You'll have to test and adapt them though, and define them as external requesters in the PyKota configuration file. ============================================================ INSTALLATION: ============= WARNING : ========= If you run a PyKota version lower than 1.01, you definitely have to upgrade you Quota Storage Database. Please read the documentation included in the initscripts subdirectory first ! Prerequisite : -------------- You need to have the following tools installed on the CUPS Server : - CUPS - Python v2.1 or above - eGenix' mxDateTime Python extension - PostgreSQL's PygreSQL Python extension and the PostgreSQL client libraries. - SNMP tools (specifically the snmpget command) You need to have the following tools installed on the Quota Storage Server : - PostgreSQL PygreSQL and the PostgreSQL client libraries's versions on the CUPS Server must match the PostgreSQL version used on the Quota Storage Server. This list of prerequisite software may change in the future, when PyKota will support more functionnalities you will be given alternatives. Of course the CUPS Server and the Quota Storage Server can be the very same machine if you've got a tiny network, or you can have multiple CUPS Servers all storing their quotas on the same Quota Storage Server if you've got a bigger network. Then : ------ Download the latest PyKota version from the CVS tree on : http://savannah.nongnu.org/projects/pykota Just type : python setup.py install You may need to be logged in with sufficient privileges (e.g. root) The installation script will now automatically check if some software is missing and ask you if you still want to proceed with the installation or abort it completely. Go to the initscripts subdirectory of PyKota's sources, and choose the appropriate storage backend for your configuration. Read the associated README file and execute the initialization script to create an empty PyKota Storage. Upgrade scripts may be provided as well. Copy the conf/pykota.conf.sample sample configuration file to /etc/pykota.conf, and adapt this file to your own needs and configuration. Modify the PPD files for each printer on which you want to manage print quotas, for example /etc/cups/ppd/lp.ppd : --- Add the line below exactly as-is somewhere near the top --- *cupsFilter: "application/vnd.cups-postscript 0 /usr/bin/pykota" --- Add the line above exactly as-is somewhere near the top --- Modify the path to the pykota executable if needed, unfortunately you have to supply the correct absolute path here due to CUPS internals, or put the pykota executable into /usr/lib/cups/filter instead of into /usr/bin. Do this for each ppd file present in this directory if you want to enable quota on every printer. WARNING : In the case you've got a non-postscript printer, chances are that the *cupsFilter is already filled-in and points to cupsomatic or such a print filter. In this case please check if you can switch your printer to PostScript mode or if there's a way to make it accept PostScript jobs. If yes then ensure that your workstations uses a PostScript printer driver, and replace the *cupsFilter line with the one pointing to the pykota filter. This should work, but is currently untested. If your printer really needs the original *cupsFilter line then you may not be able to use PyKota easily for now. Add printers and users to the quota system and set their quota values : $ edpykota --add -P printer -S softlimit -H hardlimit user1 ... userN launching edpykota without any argument or with the --help command line option will show you all the possibilities. Restart CUPS, for example under Debian GNU/Linux systems : $ /etc/init.d/cupsys restart Your users now should be able to print but not exceed their printing quota. To see printer command usage, you can use : $ repykota --printer lp or : $ repykota which will print quota usage for all users on all printers, along with totals. WARNING : as of today, 2003-02-06, group quotas are not implemented. SECURITY : You should ensure that only the print quota administrator can run the warnpykota command, but this is actually not enforced in the program. Any user able to launch warnpykota could flood over-quota users' email boxes. You should ensure that only the print quota administrator can run the edpykota command, but this is actually not enforced in the program. Otherwise, any user could modify his/her or other people's print quota. launching : chmod 750 /usr/bin/warnpykota /usr/bin/edpykota should make you reasonably safe. ============================================================ Please e-mail bugs to: alet@librelogiciel.com (Jerome Alet)