Editing USB Printing in VE

This howto tries to cover the "device" configuration for printing with a USB printer in a Container.
Please refer to your specific distro for required printing packages.
Please note that ownership/permission/devices are referred to my system and you have to adapt to YOUR configuration: they are reported only as an EXAMPLE.

* Install '''usbutils''' in both HN and VE. 
* In a shell on HN type '''lsusb''' and you'll get the list fo the usb devices on your system:
  Bus 002 Device 006: ID 0dda:2026 Integrated Circuit Solution, Inc. USB2.0 Card Reader
  Bus 002 Device 005: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
  Bus 002 Device 003: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
  Bus 002 Device 001: ID 1d6b:0002  
  Bus 008 Device 005: ID 04b8:0005 Seiko Epson Corp. Stylus Printer
  Bus 008 Device 001: ID 1d6b:0001  
  Bus 007 Device 002: ID 046d:c044 Logitech, Inc. 
  Bus 007 Device 001: ID 1d6b:0001  
  Bus 006 Device 002: ID 051d:0002 American Power Conversion Uninterruptible Power Supply 
  Bus 006 Device 001: ID 1d6b:0001  
  Bus 001 Device 001: ID 1d6b:0002  
  Bus 005 Device 001: ID 1d6b:0001  
  Bus 004 Device 001: ID 1d6b:0001  
  Bus 003 Device 001: ID 1d6b:0001 
* Now examine the output of your command and you'll see two important lines: one for your printer and one for the usb port at which is attached, in my case:
  Bus 008 Device 005: ID 04b8:0005 Seiko Epson Corp. Stylus Printer
  Bus 008 Device 001: ID 1d6b:0001
* In '''/dev''' directory in HN you should have:
** a '''symlink''' to your usb printer: <code>lrwxrwxrwx 1 root root 7 Nov 28 14:14 usblp0 -> usb/lp0</code>
** a '''usb''' directory
** a '''printer inside''' the /dev/usb directory: <code>crw-rw---- 1 root lp 180, 0 Nov 28 14:14 lp0</code>
** a '''bus/usb''' directory
** '''many directories''' in bus/usb: named with the bus numer that you got with the first lsusb command. In this example the relevant one is '''008'''
** in the numbered subdirectory '''1 file for every usb device attached to this bus''', the first one is the usb port:
***<code>crw-rw-r--  1 root usb  189, 896 Nov 24 16:16 001</code>
***<code>crw-rw-r--  1 root usb  189, 900 Nov 28 14:14 005</code>
* Now that you have an idea of the general structure of your usb devices you have to replicate them on your VE.
** enter your VE: <code>vzctl enter VE_NUMBER</code>
** create in /dev (if not present) the usb directory
** create in /dev/usb the printer device typing: <code>mknod lp0 c 180 0</code>
*** give the correct ownership/permission to the new created device typing:
**** <code>chown root:lp lp0</code>
**** <code>chmod 660 lp0 </code>
**** check with <code>ls -l lp0</code> if the new device is '''IDENTICAL''' to the one in HN --> <code>crw-rw---- 1 root lp 180, 0 Nov 27 13:51 lp0</code>
** go back to /dev and create a symlink to the printer device: <code>ln -s /dev/usb/lp0 /dev/usblp0</code>
** create all the needed directories:
*** <code>mkdir /dev/bus</code>
*** <code>mkdir /dev/bus/usb</code>
*** <code>mkdir /dev/bus/usb/008</code>
** switch to /dev/bus/usb/008 directory and create there the needed devices: one for the usb port and one for the printer
*** <code>mknod 001 c 189 896</code>
*** <code>mknod 005 c 189 900</code>
** assign ownership/permissions:
*** <code>chown root:usb *</code>
*** <code>chmod 664 * </code>
*** check everything: <code>ls -l</code> should give the same results as in HN:
***<code>crw-rw-r--  1 root usb  189, 896 Nov 27 13:29 001</code>
***<code>crw-rw-r--  1 root usb  189, 900 Nov 27 13:30 005</code>
* '''Doublecheck everything!'''
* Now edit your VE_NUMBER.conf adding this line: <code>DEVICES="c:180:0:rw c:189:896:rw c:189:900:rw"</code>
** These are the devices replicated in the VE with mknod.
* Almost there: restart your VE and enter it.
* In VE type: <code>lsusb</code> and you should see the two devices created before:
  Bus 008 Device 005: ID 04b8:0005 Seiko Epson Corp. Stylus Printer
  Bus 008 Device 001: ID 1d6b:0001
* If not '''RECHECK''' everything.
* Start cups and access it via your browser
* You should be able to see the printer attached to the usb port

== Sample bash shell script for compute vzctl command for dynamically assigning some devices to one VZ ==
Be care, the command <code>vzctl set xxx --devices "dddd" --devnodes "nnnn" --save</code> will reassign
the entire list of devices shared to one VZ, even suppressing some already presents.
<code>
  #!/bin/bash
  VZ=1234
  DEVICES="[bB]luetooth|[pP]rinter"
  
  VZDEV=""
  VZNOD=""
  
  while read A B C D E;do
    if [[ "$E" =~ (${DEVICES}) ]] ;then
        BUS=${B#0} DEV=${D%:}
        BUS=${B#0} DEV=${DEV#0}
        DEV=${DEV#0}
        VZDEV="$VZDEV c:189:$(((BUS-1)*128+DEV-1)):rw"
        VZNOD="$VZNOD bus/usb/$B/${D}rw"
        fi
    done < <(lsusb)
  
  printf "DEVICES=\"%s\"\n" "${VZDEV# }"
  printf "DEVNODES=\"%s\"\n" "${VZNOD# }"
  printf "vzctl set %d --devices '%s' --devnodes '%s' --save\n" $VZ "${VZDEV# }" "${VZNOD# }"
</code>

[[Category:HOWTO]]