Unable to install printer

[tatanas]

I Updated Fog to 1.5.9. The problem is still the same.

How Fog client checks if a printer is already installed ?

[Sebastian Roth]

@tatanas said in Unable to install printer:

How Fog client checks if a printer is already installed ?

Check out this part of the fog-client code: https://github.com/FOGProject/fog-client/blob/85da019cbd8a939e69fea42779f1bc53b06323cb/Modules/PrinterManager/PrinterManager.cs#L81

[Matthieu Jacquart]

@tatanas Hi, it looks like same problem I’m facing since few month too, no workaround for now…
https://forums.fogproject.org/topic/15185/problem-mapping-network-printer-after-upgrade-to-1-5-9-60?_=1631803438100
Matthieu

[tatanas]

@sebastian-roth
Don’t hesitate if you need help debugging.
I’m using the module a lot and this bug is very frustating…

@Matthieu-Jacquart
The bug was there in 1.5.8 too and I think it wasn’t before.

[tatanas]

So it seems the list “_configuredPrinters” contains the printer that I want to install.
Is it the host’s printers list configured through the fog server web ?
And the “installedPrinters” list will be the printers already installed on the host ?

[tatanas]

I can understand “…already exists” but what does “… already configured” mean ?

Here is a sample of the log when I try to install a printer which is not already installed on the host :

 22/09/2021 15:58 PrinterManager Adding printers
 22/09/2021 15:58 Printer Adding: B503-LASER (fog)
 22/09/2021 15:59 PrinterManager PrintUI return code = 0
 22/09/2021 15:59 PrinterManager Restarting spooler

...

 22/09/2021 16:02 PrinterManager Adding printers
 22/09/2021 16:02 PrinterManager B503-LASER (fog) has already been configured

...

 22/09/2021 16:04 PrinterManager Adding printers
 22/09/2021 16:04 PrinterManager B503-LASER (fog) has already been configured

I you want, I can give you a remote access to this computer.

[tatanas]

More details :
I tried adding 2 Fog managed printers and the ports are created (IP_X.X.X.X with the associated IP) but not the printers.
I would say the printui method (even if return code is 0) is not working properly.

[Sebastian Roth]

@tatanas Finally I found some time to look into this in more depth. Most of the fog-client code came from Joe who is not actively working on this project anymore. While I try to fix things in the fog-client as much as I can I don’t know it well.

As far as I understand things the problem might occour because _configuredPrinters is an internal list the fog-client keeps to know which printer was configured earlier already to skip that on the next loop. But obviously a situation can arise where the rundll32 PrintUI calls return but still the printer is not setup correctly. In that case the fog-client code add it to its internal list of _configuredPrinters and won’t try to configure it until you restart the fog-client service (FOGService in Windows service managment).

So what we need to find out is why this part is not working as it should: https://github.com/FOGProject/fog-client/blob/master/Modules/PrinterManager/Windows/WindowsPrinterManager.cs#L124

[tatanas]

@sebastian-roth We need detailed log of printui command result.
The command in the client code is the same I have used to test from command line (test was ok), so it’s strange it doesn’t work.

[Sebastian Roth]

@tatanas Maybe there is some message in the Windows event log? Just a quick idea from the top of my head. I will try to find some time to help you on getting fog-client compiled soon as well.

[tatanas]

@sebastian-roth I checked Windows event log (spooler log) and didn’t find anything regarding the printer installation.
Thanks for your time.

[tatanas]

Ok, thanks to you I can build the Fog Client (https://forums.fogproject.org/topic/15757/fog-client-build).
I would like to log the result of the printui command in WindowsPrinterManager.cs at line 41.
I added “> c:\printui.log” but it doesn’t work.

using (var proc = Process.Start("rundll32.exe", $" printui.dll,PrintUIEntry {cmdLine} > c:\\printui.log"))

I don’t know C# so I suppose I could use a method to get Standard Output ?

[Sebastian Roth]

@tatanas This answer on stackoverflow looks promising: https://stackoverflow.com/a/18529868

[tatanas]

@sebastian-roth Here are the changes I made in the WindowsPrinterManager.cs at line 41:

using (Process proc = new Process())
{
	proc.StartInfo.FileName = "rundll32.exe";
	proc.StartInfo.Arguments = $" printui.dll,PrintUIEntry {cmdLine}";
        proc.StartInfo.RedirectStandardOutput = true;
	proc.StartInfo.UseShellExecute = false;
	proc.Start();
	var output = proc.StandardOutput.ReadToEnd();
	proc.WaitForExit(30*1000);

        if (proc.HasExited)
        {
              Log.Entry(LogName, "PrintUI return code = " + proc.ExitCode);
	      Log.Entry(LogName, "PrintUI Output = " + output);
        }
        else
        {
              Log.Entry(LogName, "PrintUI has not finished in a timely fashion, abandoning process");
        }
}

replacing

using (var proc = Process.Start("rundll32.exe", $" printui.dll,PrintUIEntry {cmdLine}"))
{
...
}

Unfortunatly, printui does not return anything…

Logging the “cmdLine” variable returns this when the first installation attempts:

cmdLine = /if /b "B503-LASER (fog)" /f "\\@IP_NAS\applications\Imprimantes\HP_LJ_M401\hpcm401u.inf" /r "IP_X.X.X.X" /m "HP LaserJet 400 M401 PCL 6" /q

After that, cmdLine is not used anymore and we’ve got “already configured”.
I never pass in the procedure

public override void Configure(Printer printer, bool verbose = false)
{
...
}

[tatanas]

I made some tests. The same printui command in local works fine.
So if it’s working in local it should works with fog client which means the added printer is removed/deleted from the host as soon as it’s installed ? It could explain why we can’t see the printer in the host list and why fog client says it’s already configured.

[tatanas]

Last news :

• The script never goes in the “Remove” method, so my last suggestion is wrong.
• I made a mistake about the “Configure” method. It is going into this method but it passes into

if (string.IsNullOrEmpty(printer.ConfigFile)) return;

and never execute

PrintUI($"/Sr /n \"{printer.Name}\" /a \"{printer.ConfigFile}\" m f g p", verbose);

EDIT : it is the same behaviour on a computer without problem… I’m lost

[Sebastian Roth]

@tatanas said in Unable to install printer:

I never pass in the procedure
public override void Configure(Printer printer, bool verbose = false)

Can you please explain what you mean by that?

[tatanas]

@sebastian-roth Sorry I made a mistake, like I said in my previous post, the “Configure” method is called but does nothing (always enter the second “if”).

[tatanas]

This problem is very strange.
I was testing on a win7 computer which can’t install printers (fog client 0.12).
I push a old fog image on it and with the same 0.12 client, it now works.
It is not really up to date and the problem appears on win10 too (different version).

[Sebastian Roth]

@tatanas Maybe the changes that came when MS fixed the printer nightmare issue is causing the problem.