CUPS (ALPINE) - CUPS claiming print job completed despite printing nothing, How to debug the issue? (network printer, Alpine, Linux, Docker)

vinnu543 · 10-31-2018, 09:13 AM

CUPS version 2.2.6

I am using a Network printer, with
URI : socket://192.168.20.185
RAW protocol

--> Tried to print it through terminal, with no success.
ping 192.168.20.165 shows the network printer connection is open.

In addition I got the following errors:

lpr: Error - scheduler not responding

lpstat: Bad file descriptor

--> Tried to debug through view ErrorLog page, the page is Forbidden.

Here is my "cupsd.conf"

Code:

Listen 631
Listen /run/cups/cups.sock
Browsing On
BrowseLocalProtocols dnssd
DefaultAuthType Basic
WebInterface Yes
<Location />
  Allow All
  Order allow,deny
  Allow From 127.0.0.1
  Allow From 192.168.20.185
</Location>
<Location /admin>
  Allow All
  Require user @SYSTEM
  Order allow,deny
  Allow From 127.0.0.1
  Allow From 192.168.20.185  
</Location>
<Location /admin/conf>
  Allow All
  AuthType Default
  Require user @SYSTEM
  Order allow,deny
  Allow From 127.0.0.1
  Allow From 192.168.20.185
</Location>
<Location /admin/log>
  AuthType Default
  Require user @SYSTEM
  Order allow,deny
  Allow From 127.0.0.1
  Allow From 192.168.20.185
</Location>
<Policy default>
  JobPrivateAccess all
  JobPrivateValues none
  SubscriptionPrivateAccess default
  SubscriptionPrivateValues default
  <Limit Create-Job Print-Job Print-URI Validate-Job>
    Order deny,allow
  </Limit>
  <Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job Cancel-My-Jobs Close-Job CUPS-Move-Job CUPS-Get-Document>
    Require user @OWNER @SYSTEM
    Order deny,allow
  </Limit>
  <Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices>
    AuthType Default
    Require user @SYSTEM
    Order deny,allow
  </Limit>
  <Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
    AuthType Default
    Require user @SYSTEM
    Order deny,allow
  </Limit>
  <Limit Cancel-Job CUPS-Authenticate-Job>
    Require user @OWNER @SYSTEM
    Order deny,allow
  </Limit>
  <Limit All>
    Order deny,allow
  </Limit>
</Policy>
<Policy authenticated>
  JobPrivateAccess all
  JobPrivateValues none
  SubscriptionPrivateAccess default
  SubscriptionPrivateValues default
  <Limit Create-Job Print-Job Print-URI Validate-Job>
    AuthType Default
    Order deny,allow
  </Limit>
  <Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job Cancel-My-Jobs Close-Job CUPS-Move-Job CUPS-Get-Document>
    AuthType Default
    Require user @OWNER @SYSTEM
    Order deny,allow
  </Limit>
  <Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default>
    AuthType Default
    Require user @SYSTEM
    Order deny,allow
  </Limit>
  <Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
    AuthType Default
    Require user @SYSTEM
    Order deny,allow
  </Limit>
  <Limit Cancel-Job CUPS-Authenticate-Job>
    AuthType Default
    Require user @OWNER @SYSTEM
    Order deny,allow
  </Limit>
  <Limit All>
    Order deny,allow
  </Limit>
</Policy>
<Policy kerberos>
  JobPrivateAccess all
  JobPrivateValues none
  SubscriptionPrivateAccess default
  SubscriptionPrivateValues default
  <Limit Create-Job Print-Job Print-URI Validate-Job>
    AuthType Default
    Order deny,allow
  </Limit>
  <Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job Cancel-My-Jobs Close-Job CUPS-Move-Job CUPS-Get-Document>
    AuthType Default
    Require user @OWNER @SYSTEM
    Order deny,allow
  </Limit>
  <Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default>
    AuthType Default
    Require user @SYSTEM
    Order deny,allow
  </Limit>
  <Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
    AuthType Default
    Require user @SYSTEM
    Order deny,allow
  </Limit>
  <Limit Cancel-Job CUPS-Authenticate-Job>
    AuthType Default
    Require user @OWNER @SYSTEM
    Order deny,allow
  </Limit>
  <Limit All>
    Order deny,allow
  </Limit>
</Policy>
ServerAlias *
DefaultEncryption Never

How to debug this issue here?

MensaWater · 11-01-2018, 12:39 PM

Are you sure the IP in your socket is actually used by the printer you think it is? i.e. Is it possible it did send the print but to a different printer that has that IP?

What happens if you do "telnet 192.168.20.185" (or nc -C 192.168.20.185)?

What if you specify port 9100?

Mike_Walsh · 11-01-2018, 03:18 PM

As far as CUPS is concerned, once it's delivered the print job to the printer's memory buffer, its involvement in the process has finished. From that point on, it's down to the printer itself.

As with MensaWater, I agree the network printer 'socket' process is more likely to be the culprit. It's not always easy to get right. Even experienced Linux users aren't always successful.

If your printer drivers are properly installed & configured, then you won't get any warning from CUPS about that. With a 'socket' config in use, if CUPS has 'delivered' correctly, but the socket isn't set-up properly, then that print job just disappears into thin air.....

Mike.