FC8 FreeNX Issues - "Permission Denied".

[ScottishCaptain]

Okay.

Yes, I've searched the forum on this one to no avail.

I've got a new FC8 x86_64 installation running FreeNX 7.1 on it.

Everything is working- sort of. SSH connection is a go and works fine, but when I try to connect, I get:

NX> 203 NXSSH running with pid: 6365
NX> 285 Enabling check on switch command
NX> 285 Enabling skip of SSH config files
NX> 285 Setting the preferred NX options
NX> 200 Connected to address: 10.0.1.4 on port: 22
NX> 202 Authenticating user: nx
NX> 208 Using auth method: publickey
/usr/libexec/nx/nxserver: Permission denied
NX> 280 Exiting on signal: 15

Attempting to connect via the terminal (ssh nx@localhost) yields the same thing:

Last login: Tue Jan 1 18:31:52 2008 from mybox
/usr/libexec/nx/nxserver: Permission denied
Connection to localhost closed.

What does this mean? Permissions appear to be correct in /usr/libexec/nx. My secure log shows nothing other then the client connecting via SSH properly... So I'm not sure what's going on here. It appears like nxserver is supposed to be the shell for the NX connection, but that never launches and I just get the permission denied message.

Any ideas?

-SC

[scottro]

I've found freenx to be rather borked on Fedora. I have a page on using the nomachines.com one at http://home.nyc.rr.com/computertaijutsu/rhnx.html

That's my way of saying, "I dunno, try this instead."

[ScottishCaptain]

I'd use the Nomachine NX, but it's limited to 2 concurrent connections.

The machine itself is a terminal server, so that's obviously a bad thing...

-SC

[scottro]

Well, tell the users not to be greedy.

Yes, I know, that can be an issue. My page refers to a howto that works for CentOS. In that case, I found the important thing seemed to be to either import the key as described in that howto, or to be just enable everything in the node.conf, then see what you could disable and still have it work.

I assume you checked firewalls and all that good stuff. (Scrolls up to see if you mention it) Yes, you say you can connect via ssh.

You might have to do something like /usr/libexec/nx/nxserver (or whatever the path is) start. Honestly I don't know, just the whole thing on Fedora seemed to be more trouble than it was worth for me (but I didn't need more than one connection actually, it's for a developer who had been using VNC.)

I do remember googling at the time and finding out it was somewhat borked right now in Fedora--but I think that was something that was theoretically fixed. (I don't remember what the problem was or how long ago this happened.)

The only help I can give is to say try the CentOS wiki thing, adjusting paths and the like and be sure to import the key as specified.

It's unfortunate--it's a good product with horrible docs--they direct you to something written for Fedora 4. It's probably quite easy if someone would write a doc like the CentOS one.

If you do figure it out, please document it. I was going to play with it again, but work has been so busy that I haven't had a chance.

[ScottishCaptain]

Fixed it :P.

SE Linux was preventing SSHD from launching /usr/libexec/nx/nxserver as a shell. I completely forgot that I'd enabled SELinux for this install. I threw up a SELinux policy to let SSHD execute nxserver, and all is well.

-SC

[scottro]

Glad you got it working.
Would you be kind enough to go through the steps you took to set it up? (I'm going to add them to my page.)

I got this far
yum install freenx (which pulls in nx)
Found that there was no setup script, cursed the docs, googled, found the setup script in the docs section. Hrrm, I think I ran it.)
Actually, let me try setting it up again, hopefully tomorrow night, and I'll post where I ran into issues.

IIRC, I wasn't able to add it to startup services, but had to use rc.d/rc.local--there were a few other things too.

Sigh, it was awhile ago, I'll have to try it and then probably post my questions in a new thread. (I might put your name in the thread though, in the hope that you'll see it.)

[leadgolem]

scottro has pages? Where are scottro's pages?

[scottro]

http://home.nyc.rr.com/computertaijutsu/

There's a Fedora section mentioned in the index.

[leadgolem]

Thanks scottro.

[ScottishCaptain]

Eh...

I'm just moving my F8 box right now, so I'll post later about the details.

Off the top of my head, there are no startup scripts to deal with- at least not with FreeNX (though there are with NX Commercial).

FreeNX sets up an NX user account on your system for SSH use. You can ONLY connect to "nx" with the public key (/etc/nxserver/client*), since the account has NO password.

"nx" has the shell set as /usr/libexec/nx/nxserver. So when the NX client connects using the public key, nxserver is automatically launched as required, which does whatever voodoo it does and establishes the X connection (using the NX libraries somehow or other). I don't believe there's anything else to it then that, the nxserver script seems to be where the majority of the action happens.

The devil is in the details with FreeNX, and I'll post a howto soon. It's really simple to setup, but yes, there's no good documentation, which really makes the entire thing confusing as hell (took me 2 hours- shoulda been a 2 minute job).

-SC

[scottro]

Yup, that pretty much echoes my experience. As I said, (I think) I added a section on setting it up in Fedora, finally. As you said, it is about a 2-3 minute job that took two hours, most of it searching for documentation and files.

[Henry2630]

It's amazing. I seem to have problems with everything EXCEPT NX!

I have a Fedora 8 box, forget SELinux, I've had no end of problems with it.

I downloaded the RPM's with Firefox and it auto-inatalled then. Downloaded Node, Client Server.

Then I went to a workstation installed the Windows FreeNX Client, and it worked 100%. Never had a problem with it. 'Bout the only thing I HAVEN'T had a problem with!

[mcalautt]

so how did you set up a policy so selinux would allow
ssh to run /usr/libexec/nx/nxserver ??

I have the same prob..
just installed FC8

thanks
mike

[Henry2630]

I avoid selinux like the plague! We use a hardware Firewall now and before that I used Firestarter.

I had NO problems on Fedora to install NX. I install the node, the client and the server in that order.

Then download the NC Client for windows (or Linux) and it works out of the box.