Hi Ted,

On Mo 08 Aug 2011 18:04:18 CEST Ted Barnes wrote:

We are experimenting with X2go (very cool), but having a devil of a
time getting printing to work. This request for help is keying off
of posts by John Sullivan and Mario Oroz (thanks so much for those,
guys, e.g., see tread
http://www.mail-archive.com/x2go-user@lists.berlios.de/msg00104.html
and
http://www.mail-archive.com/x2go-user@lists.berlios.de/msg00115.html). We
are having pretty much the same problem as described there. We are
assuming that X2go printing in general can be made "to work" and
that this is a matter of something we are doing wrong (maybe
starting with the install?), some necessary "tweaks", etc.

To make sure you use latest software, please use these sources for
installation of the server-side of X2go:

Debian+Ubuntu: http://wiki.x2go.org/nightly-built_packages_debian_ubuntu

Furtheron for initial debugging, please use x2goclient on Debian or
Ubuntu to eradicate some not-so-generic Windows problems.

Please install the x2goclient from our nightly builds as well.

Nightly builds are for debugging+testing, not for production setups, though!

We'd like to post this on the developer's list too to see if that's helpful.

We're hoping to get a number of questions answered, and have
provided what may be "too much" description below:

Questions:

Q: Did we miss something during the setup and installation process?

I will comment your description about setup and installation below, so
please read the answers to this question there.

The latest general infos are found in our wiki:

http://wiki.x2go.org

Q: Our server does not have a /root/.x2go/ssh/.x2oprint/id_dsa"
directory or id_dsa file - do these need to get created by hand? In
fact, our server does not have an "id_dsa" file anywhere on the
machine. If we need to add this, how does one do so (i.e., using
the normal ssh key creation process)? We have some other dsa files,
but not one with the specific name id_dsa (i.e., can we use one of
the existing ones in /etc/ssh?).

These RSA/DSA files are part of SSH pub/priv authentication and can be
created with the ssh-keygen tool. Refer to its man page for further
info.

Q: We assume X2goprint and cups-x2go perl scripts are part of this
picture. We don't believe they are being called by the printing
process - how would we tell? If they are necessary but not getting
called, thoughts as to why they are not getting invoked when we
print and how to fix this?

If you refer to x2goprint as separate X2go package then you are
definitely using (very) old code.

Unfortunately, the www.x2go.org site and our wiki.x2go.org pages to
give ambiguous info, this should be fixed and brought in sync ASAP
(ping@Heinz!!!).

The x2goprint script has become part of the x2goserver package and has
undergone some changes since then. Please make sure you use the
nightly build packages for testing+debugging for now (this is a
recommendation that is valid today, in the future we will bump
sub-releases in shorter intervals, the x2goserver esp. is very due for
such a nano release... Sorry for delays on this).

Q: In testing (where we simulate what we imagine the printing
process to be by doing each step manually) when we issue the .ready
command, why does that only seems to work sometimes as judged by the
x2go print client popping on the XP side? Does that tell us
something?

Good question. If the latest code does not solve your issues, please
send the .ready file's content.

Q: Should printing be putting jobs in "/" (is that normal)? Does

NO! You use old server-side packages. Upgrade to the nighly builds.

the x2goprint script know what to grab based on job#s? We assume
this all should work with multiple users and the x2goscript
identifies which jobs to grab and put them individual user spool
queues.

Yes, this does work with latest code.

Q: To work, should x2goprinting pass the print file from the server
through the ssh connection to the client? Is this in part an "ssh
passing the file" problem? We can connect through putty from the
client to the server, and assume we have the keys correct because we
can connect from XP to the Ubuntu server via x2go in the first
place. Back to the lack of an id_dsa file? Again, we're not sure
that printing is invoking the right scripts to begin with.

The print job files are stored on the client via SSHFS. The SSHFS file
sharing uses a temporary pub/priv key pair, so for this mechanism it
is not relevant if you can SSH to and from the server. The SSHFS mount
is issued by the server and connects to the client (via a SSH tunnel).

Q: Assuming we get this working, we also assume that on the
Ghostview/Ghostscript side we shouldn't be having to put the name of
the file in the command line, nor actually having to use the command
line. I.e., there is an option there to print that refers to
whatever default printer we have set on the XP machine, but
currently nothing happens if we use that particular option instead
of the command line.

Yes, this should be so. Please test this with a Linux x2goclient
first. If this works then check with the Windows x2goclient and report
experienced differences.

Q: Should we be using Posgress instead of SQLite? We are assuming
that SQLite is fine until we want to deal with load balancing.

If you want to use:

o many X2go servers (clustering) o restrictive X2go server access based on posix accounts/groups -> PostgreSQL

o one X2go server o access for any non-system posix User (everyone who can use SSH) -> SQLite

DESCRIPTION

We are connecting from XP machines using x2goclient to Ubuntu Server
9.10 (connecting is pretty consistent, a few issues now and then but

For testing, please use a Linux client. The latest X2go code is only
available for Ubuntu >=10.04. For older Ubuntu versions you should be
able to either

o backport X2go from X2go Git o use the server-side packages for Debian lenny (no nightly builds, though): http://wiki.x2go.org/adding_the_x2go_repository_debian

all in all it works well) over Comcast or Fios connection (DSL too
slow). We are using the X2go with SQLite, cups-x2togo and
x2goprint; we have not installed any of the optional "bindings"
packages. We used visudo to add the line "x2goprint All=(ALL)
NOPASSWD: /usr/bin/x2goprint", and added an "x2goprinter" user by
hand (that action also created an "x2goprinter" group to which we
added our test user accounts).

user=groupname='x2goprint', not 'x2goprinter'!!!

We have tried uncommenting the settings to activate them in
"/etc/cups/cups-x2go.conf" (even though we understand these settings
to be used only for a separate cups server) with no change. As
noted above, our server does not have an id_dsa file and while we
suspect that as being part of the problem we would have assumed that
file would be created as part of the install pocess.

With latest X2go code, printing works out of the box (to my experience).

On the server, we have a minimal "Ubuntu Desktop" installed so we
can use Firefox to browse from the server.

We have GSview 4.9 and Ghostscript 9.02 installed on the XP clients.

Is this needed for x2goclient??? I do not think so... The Ghostscript
stuff is needed on the client side... However, a PDF viewer will be
helpful on the Windows client. For testing though: use a Linux machine
as a client.

We are trying to print to an older HP Laserjet 4000 shared out on
local XP machine (this 2nd machine is not one connecting to the
Ubuntu server, no X2go on it, no Ghostview or Ghostscript) and
another HP color laser that is a network device. All printing
behavior is the same regardless of which printer we try.

Should work.

We are hoping outlining the following will help describe what we
think is going on, and possible not working:

1. On the 9.10 Ubunu server, we installed X2go printing. If we go
   to System->Administration->Printing, we can see a
   "Generic-Cups-X2go-Printer" and it is active. Its properties
   include a URI of "cups-x2go:/". On the same Printer Configuration
   window, if we press Server->Connect the resulting Cups server is
   "/var/run/cups/cups.sock". We are using a 64 bit machine, and can
   find two instances of the "cups-x2go" and maybe this is part of the
   problem (one is is /usr/lib64/cups/backend, the other in
   usr/lib/cups/backend)?

AFAIK /usr/lib64 is a symlink to /usr/lib. So no worries necessary
about this. The only thing you should make sure is to have these
permissions set on the cups-x2go backend:

-rwx------ root root /usr/lib/cups/backend/cups-x2go

This permission setting marks the backend in a way that CUPS knows it
has to start it with root privileges. Otherwise it is started with
user privileges and that will fail in this context.

2. If we print from the server, we briefly see a job get created
   both on the top (right) panel and if we are watching in the Print
   Configuration window. Jobs are stored in "/" and stay there until
   we delete or move them with names that follow the syntax
   "jobname-username-cupsjob#". Their permissions are root as owner,
   lp as group, and no access for users.

-> An old version of x2goprint did this...

For each print file, there is another cups file of some sort stored
in "var/spool/cups" with names like "c00052". This describes what
occurs consistently. The jobs get "printed" but nothing happens on
the windows client side or on the printer.

-> Upgrade the server-side to x2goserver from nightly builds (on an
Ubuntu >=10.04 machine).

3. [...]

Looking forward to your follow up after you have upgraded X2go (and
reported as the new versions you use for testing).

Greets, Mike

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