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OpenPrinting / ipp-usb

ipp-usb -- HTTP reverse proxy, backed by IPP-over-USB connection to device
BSD 2-Clause "Simplified" License
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systemd service: should start verbose in foreground #10

Closed OdyX closed 3 years ago

OdyX commented 3 years ago

When run in systemd service, ipp-usb udev forks in background, systemd is configured to try catching up with it by gessing it's main PID, and the type is set to forking: https://github.com/OpenPrinting/ipp-usb/blob/af7189461a8f742a830e41e4b29c225ead4b5144/systemd-udev/ipp-usb.service#L7-L9

This seems overly complicated while a simple oneshot service would achieve pretty much the same effect, with additional journal support:

 Type=oneshot
 ExecStart=/sbin/ipp-usb udev

?

alexpevzner commented 3 years ago

Well, I'm not udev expert :-)

Is my understanding correct, you suggest to replace the entire content of [Service] section with the following:

[Service]
Type=oneshot
ExecStart=/sbin/ipp-usb udev
OdyX commented 3 years ago

I think the following full-file should work (note I've added the Documentation line):

[Unit]
Description=Daemon for IPP over USB printer support
Documentation=man:ipp-usb(8)
After=cups.service avahi-daemon.service
Wants=avahi-daemon.service

[Service]
Type=oneshot
ExecStart=/sbin/ipp-usb udev

The only printer I have a USB connection on is an HP LaserJet Professional P1102W, which doesn't seem to do anything with ipp-usb, so you might want to test this.

alexpevzner commented 3 years ago

I'm currently on my countryside home, while my 25 kg weigh printer is not, so I can test on a real hardware only at the end of next week.

@tangyanli, could you please help us with testing? If yes, please replace the content of the /lib/systemd/system/ipp-usb.servicefile with the content included into the previous message, and verify that ipp-usb successfully starts when printer is connected and finishes when printer is disconnected.

This effort is a part of ipp-usb integration into the official Debian distro.

Thanks in advance!

tangyanli commented 3 years ago

@alexpevzner I am glad to do it. I will commit test result here next monday (the printers are not around at the weekend)

tangyanli commented 3 years ago

[Test distro]: Debian10 & Fedora32 [Test Printer]: Canon MF745C, Canon MF643C [Test Result]:   Plug and Unplug one USB printer: OK   Plug and unplug two USB printers: OK

alexpevzner commented 3 years ago

Thank a lot, Tess!

@OdyX, I've updated the file

alexpevzner commented 3 years ago

Closed - fixed