On Fri 14 Jun 2019 at 23:32:50 -0400, Gary Dale wrote:
> I thought I'd figured it out - that the network printer shouldn't be
> installed locally, because it's automagically discovered. I tested this by
As we have seen, it is the way you installed the queue on the client
(with a Samsung driver) that is the problem; a local driverless or
everywhere queue is no problem. But, as you say, why bother to do even
that if cups-browsed can do it for you. It's a user's choice.
> deleting the local install of the network printer and, while it disappears
> from the CUPS web interface, it still shows up in the list of printers when
> I try to print a PDF from Okular. This seems somewhat reasonable...
Having this deleted queue show in Okular's dialog doesn't seem at all
reasonable to me.
> Unfortunately, printing to it does nothing. The output disappears into the
> ether(net).
The queue has been deleted. The job has nowhere to go!
> To be clear, the printer network connection is there. CUPs lists it multiple
> times with its network address when I use the web interface to find new
> printers. And I can ping its IP address.
>
> I then fired up a Stretch VM and tried the same things. Under Stretch, the
> printer doesn't show up except as the USB-shared printer from the server.
> However, after installing the Samsung driver, it did show up when I tried to
> find new printers from the CUPS web interface. I installed it using the
> SEC30CDA71CB48A "address" and the normal C410 driver and was able to print
> successfully.
>
> CUPS is apparently working differently in Buster than in Stretch in its
> handling of network-attached printers.
A little differently when the driverless aspect is factored in. But,
basically, the framework is still the same. CUPS/cups-filters has
changed because printers have changed.
> Anyway, here's my current diagnostic output:
>
> $ lpstat -l -e
> Samsung_C410_Series_SEC30CDA71CB48A_ network none
> ipp://Samsung%20C410%20Series%20(SEC30CDA71CB48A)._ipp._tcp.local/
I think that is the printer. We need avahi-browse to tell us more.
> Samsung_C410_Series_TheLibrarian network none
> ipps://Samsung%20C410%20Series%20%40%20TheLibrarian._ipps._tcp.local/cups
That's the queue set up automatically by cups-browsed using its
driverless utility.
> $ lpoptions -p Samsung_C410_Series_SEC30CDA71CB48A_
> device-uri=ipp://Samsung%20C410%20Series%20(SEC30CDA71CB48A)._ipp._tcp.local/
> printer-info='Samsung C410 Series (SEC30CDA71CB48A)' printer-location
> printer-make-and-model='Samsung C410 Series' printer-type=16810060
Ok.
> $ lpoptions -p Samsung_C410_Series_TheLibrarian
> device-uri=ipps://Samsung%20C410%20Series%20%40%20TheLibrarian._ipps._tcp.local/cups
> printer-info='Samsung C410 Series @ TheLibrarian' printer-location='family
> room' printer-make-and-model=ColorLaserPrinter printer-type=16781390
Ok.
> # cupsfilter -p /etc/cups/ppd/Samsung_C410_Series_TheLibrarian_ppd -m
> printer/foo -e --list-filters /etc/nsswitch.conf
> cupsfilter: Unable to open PPD file: Unable to open PPD file on line 0.
> Segmentation fault
>
> # ls -l /etc/cups/ppd/
> total 476
> -rw-r----- 1 root lp 192111 Jun 14 21:01
> EPSON_Stylus_Photo_R300_TheLibrarian.ppd
> -rw-r----- 1 root lp 78398 Dec 9 2018 EPSON_XP-820_Series.ppd
> -rw-r----- 1 root lp 78390 Nov 5 2018 EPSON_XP-820_Series.ppd.O
> -rw-r----- 1 root lp 43299 Jun 14 21:01
> HP_Color_LaserJet_CP1215_TheLibrarian.ppd
> -rw-r----- 1 root lp 21016 Jun 14 21:01 PDF_TheLibrarian.ppd
> -rw-r----- 1 root lp 32048 Jun 14 21:01
> Samsung_C410_Series_TheLibrarian.ppd
> -rw-r----- 1 root lp 27498 Jun 14 21:07 Samsung_ML_1210_TheLibrarian.ppd
>
> Changing the _ppd to .ppd removes the error messages. Instead I get no
> output.
There is no output because no processing through filters takes place on
the client now you are not using the Samsung driver.
Have a go at this:
1. Check that you can print the file /etc/nsswitch.conf from the server:
lp -d Samsung_C410_Series /etc/nsswitch.conf
2. Stop cups-browsed on the client:
systemctl stop cups-browsed
3. Check destinations:
lpstat -l -e
4. Print the same file as before:
lp -d Samsung_C410_Series_TheLibrarian /etc/nsswitch.conf
--
Brian.
