An error occurred while connecting: 2: File o directory non esistente.

Hello,

This seems like an issue with the epoptes service. Could you please provide
us with your /var/log/epoptes.log?

Thanks!

2014-08-09 23:16 GMT+03:00 franziski <email address hidden>:

> Question #252869 on Epoptes changed:
> https://answers.launchpad.net/epoptes/+question/252869
>
> Summary changed to:
> An error occurred while connecting: 2: File o directory non esistente.
>
> Description changed to:
> Epoptes works great, but some time, randomly, it does't start (error:
> file or directory not existing, but don't say which one) so I have to
> restart epoptes service to run it. Is it a bug or misconfiguration? I
> used group "teachers" as group of user authorized to launch epoptes. The
> group "teachers" is LDAP not in /etc/groups. Thanks for the help.
>
> The following output of command strace -e trace=file epoptes
>
> open("/skole/tjener/home0/franz/.config/epoptes/groups.json", O_RDONLY) = 8
> Connection with epoptes failed:
> An error occurred while connecting: 2: File o directory non esistente.
>
> --
> You received this question notification because you are a member of
> Epoptes Developers, which is an answer contact for Epoptes.
>
> --
> Mailing list: https://launchpad.net/~epoptes
> Post to : <email address hidden>
> Unsubscribe : https://launchpad.net/~epoptes
> More help : https://help.launchpad.net/ListHelp
>

Marking as Needs information.

franz@tjener:~$ cat /var/log/epoptes.log

2014-08-07 08:49:34+0200 [-] Log opened.
2014-08-07 08:49:34+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-07 08:49:34+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-07 08:49:34+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-07 08:49:34+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x295e368>
2014-08-07 08:49:34+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-07 08:49:34+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x295e488>
2014-08-07 11:07:13+0200 [-] Received SIGTERM, shutting down.
2014-08-07 11:07:13+0200 [-] (UNIX Port '/var/run/epoptes/epoptes.socket' Closed)
2014-08-07 11:07:13+0200 [-] Stopping factory <epoptes.daemon.guiplex.GUIFactory instance at 0x295e488>
2014-08-07 11:07:13+0200 [-] (TLS Port 789 Closed)
2014-08-07 11:07:13+0200 [-] Stopping factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x295e368>
2014-08-07 11:07:13+0200 [-] Main loop terminated.
2014-08-07 11:07:13+0200 [-] Server Shut Down.
2014-08-07 11:07:15+0200 [-] Log opened.
2014-08-07 11:07:15+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-07 11:07:15+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-07 11:07:15+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-07 11:07:15+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x1a6e2d8>
2014-08-07 11:07:15+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-07 11:07:15+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x1a6e3f8>
2014-08-07 11:07:22+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:07:24+0200 [GUI,0,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:08:03+0200 [-] Received SIGTERM, shutting down.
2014-08-07 11:08:03+0200 [-] (UNIX Port '/var/run/epoptes/epoptes.socket' Closed)
2014-08-07 11:08:03+0200 [-] Stopping factory <epoptes.daemon.guiplex.GUIFactory instance at 0x1a6e3f8>
2014-08-07 11:08:03+0200 [-] (TLS Port 789 Closed)
2014-08-07 11:08:03+0200 [-] Stopping factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x1a6e2d8>
2014-08-07 11:08:03+0200 [-] Main loop terminated.
2014-08-07 11:08:03+0200 [-] Server Shut Down.
2014-08-07 11:08:05+0200 [-] Log opened.
2014-08-07 11:08:05+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-07 11:08:05+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-07 11:08:05+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-07 11:08:05+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x17722d8>
2014-08-07 11:08:05+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-07 11:08:05+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x17723f8>
2014-08-07 11:08:08+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:12:49+0200 [GUI,0,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:12:51+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:12:54+0200 [GUI,1,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:17:42+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:17:57+0200 [GUI,2,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:20:29+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:21:11+0200 [GUI,3,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:27:24+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 11:27:59+0200 [GUI,4,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 14:38:12+0200 [-] Log opened.
2014-08-07 14:38:12+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-07 14:38:12+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-07 14:38:12+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-07 14:38:12+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x22fa2d8>
2014-08-07 14:38:12+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-07 14:38:12+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x22fa3f8>
2014-08-07 14:38:14+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 14:53:07+0200 [-] Ping timeout!
2014-08-07 14:53:07+0200 [-] Ping timeout!
2014-08-07 15:48:27+0200 [-] Ping timeout!
2014-08-07 15:48:31+0200 [-] Ping timeout!
2014-08-07 15:54:25+0200 [GUI,0,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 16:02:36+0200 [-] Ping timeout!
2014-08-07 16:02:43+0200 [-] Ping timeout!
2014-08-07 16:11:40+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 16:27:56+0200 [-] Ping timeout!
2014-08-07 16:27:56+0200 [-] Ping timeout!
2014-08-07 16:32:25+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 16:36:20+0200 [GUI,2,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 16:36:44+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 16:40:13+0200 [GUI,1,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 16:40:13+0200 [GUI,1,] Unhandled error in Deferred:
2014-08-07 16:40:13+0200 [GUI,1,] Unhandled Error
 Traceback (most recent call last):
 Failure: twisted.internet.error.ConnectionLost: Connection to the other side was lost in a non-clean fashion.

2014-08-07 16:40:13+0200 [GUI,1,] Unhandled error in Deferred:
2014-08-07 16:40:13+0200 [GUI,1,] Unhandled Error
 Traceback (most recent call last):
 Failure: twisted.internet.error.ConnectionLost: Connection to the other side was lost in a non-clean fashion.

2014-08-07 16:46:30+0200 [GUI,3,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 16:46:39+0200 [-] Ping timeout!
2014-08-07 16:46:42+0200 [-] Ping timeout!
2014-08-07 16:47:15+0200 [-] Ping timeout!
2014-08-07 16:47:24+0200 [-] Ping timeout!
2014-08-07 16:48:14+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 17:06:16+0200 [GUI,4,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-07 17:24:02+0200 [-] Ping timeout!
2014-08-07 17:24:02+0200 [-] Ping timeout!
2014-08-07 17:24:03+0200 [-] Ping timeout!
2014-08-07 17:24:05+0200 [-] Ping timeout!
2014-08-07 17:28:50+0200 [-] Ping timeout!
2014-08-07 17:28:50+0200 [-] Ping timeout!
2014-08-07 17:30:08+0200 [-] Ping timeout!
2014-08-07 17:30:08+0200 [-] Ping timeout!
2014-08-07 18:32:33+0200 [-] Ping timeout!
2014-08-08 11:43:55+0200 [-] Log opened.
2014-08-08 11:43:55+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-08 11:43:55+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-08 11:43:55+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-08 11:43:55+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x11632d8>
2014-08-08 11:43:55+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-08 11:43:55+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x11633f8>
2014-08-08 11:44:00+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-08 11:44:02+0200 [GUI,0,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-08 11:50:45+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-08 11:51:28+0200 [GUI,1,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-09 15:37:53+0200 [-] Log opened.
2014-08-09 15:37:53+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-09 15:37:53+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-09 15:37:53+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-09 15:37:53+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x1f5b2d8>
2014-08-09 15:37:53+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-09 15:37:53+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x1f5b3f8>
2014-08-09 15:37:57+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-09 15:38:00+0200 [GUI,0,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-09 15:38:06+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-09 15:38:11+0200 [GUI,1,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-09 15:39:08+0200 [-] Ping timeout!
2014-08-09 22:25:08+0200 [-] Log opened.
2014-08-09 22:25:08+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-09 22:25:08+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-09 22:25:08+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-09 22:25:08+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x25692d8>
2014-08-09 22:25:08+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-09 22:25:08+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x25693f8>
2014-08-09 22:26:39+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-09 22:28:55+0200 [GUI,0,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-09 22:52:38+0200 [-] Ping timeout!
2014-08-09 22:52:45+0200 [-] Ping timeout!

Which epoptes version?
Versions <= 0.5.6 have a known ...issue with LDAP (it's actually an LDAP issue, but we worked around it in epoptes), in that the LDAP groups sometimes are not available when other services start.

Relevant question: https://answers.launchpad.net/epoptes/+question/208472
Relevant commit: http://bazaar.launchpad.net/~epoptes/epoptes/trunk/revision/340

Steps to work around the issue for versions <= 0.5.6:
sudo update-rc.d -f epoptes remove
sudo update-rc.d epoptes default 30 70

Now it starts ok, but I can't see thumbnails of clients.

You were seeing thumbnails before,
and now with that change, you don't?

If so, that doesn't make sense... do provide detailed information about your setup.

I tried to force install 0.5.7 but something was wrong so I rolled back,
installed 0.5.6 (the version available through apt-get) and now all works
fine. Excellent.

Thanks a lot for great support

2014-08-10 14:51 GMT+02:00 Alkis Georgopoulos <
<email address hidden>>:

> Your question #252869 on Epoptes changed:
> https://answers.launchpad.net/epoptes/+question/252869
>
> Alkis Georgopoulos requested more information:
> You were seeing thumbnails before,
> and now with that change, you don't?
>
> If so, that doesn't make sense... do provide detailed information about
> your setup.
>
> --
> To answer this request for more information, you can either reply to
> this email or enter your reply at the following page:
> https://answers.launchpad.net/epoptes/+question/252869
>
> You received this question notification because you asked the question.
>

The problem is solved.

Sorry, but the problem appeared again: same error message as answer. It happened after a normal apt-get update/upgrade of system. Then I make a apt-get purge epoptes and a new fresh installation (always 0.5.6): now the program starts, but I can't view thumbs of connected client.

Following, the current log:

2014-08-10 21:03:13+0200 [-] Log opened.
2014-08-10 21:03:13+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-10 21:03:13+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-10 21:03:13+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-10 21:03:13+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x2c79368>
2014-08-10 21:03:13+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-10 21:03:13+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x2c79488>
2014-08-10 21:03:57+0200 [-] Received SIGTERM, shutting down.
2014-08-10 21:03:57+0200 [-] (UNIX Port '/var/run/epoptes/epoptes.socket' Closed)
2014-08-10 21:03:57+0200 [-] Stopping factory <epoptes.daemon.guiplex.GUIFactory instance at 0x2c79488>
2014-08-10 21:03:57+0200 [-] (TLS Port 789 Closed)
2014-08-10 21:03:57+0200 [-] Stopping factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x2c79368>
2014-08-10 21:03:57+0200 [-] Main loop terminated.
2014-08-10 21:03:57+0200 [-] Server Shut Down.
2014-08-10 21:03:59+0200 [-] Log opened.
2014-08-10 21:03:59+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-10 21:03:59+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-10 21:03:59+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-10 21:03:59+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x168c2d8>
2014-08-10 21:03:59+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-10 21:03:59+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x168c3f8>
2014-08-10 21:04:08+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-10 21:27:28+0200 [GUI,0,] GUI connection lost (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))
2014-08-10 21:39:29+0200 [-] Ping timeout!
2014-08-10 21:39:37+0200 [-] Ping timeout!
2014-08-11 08:41:05+0200 [-] Log opened.
2014-08-11 08:41:05+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-11 08:41:05+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-11 08:41:05+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-11 08:41:05+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x1c8f368>
2014-08-11 08:41:05+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-11 08:41:05+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x1c8f488>
2014-08-11 08:41:11+0200 [-] Received SIGTERM, shutting down.
2014-08-11 08:41:11+0200 [-] (UNIX Port '/var/run/epoptes/epoptes.socket' Closed)
2014-08-11 08:41:11+0200 [-] Stopping factory <epoptes.daemon.guiplex.GUIFactory instance at 0x1c8f488>
2014-08-11 08:41:11+0200 [-] (TLS Port 789 Closed)
2014-08-11 08:41:11+0200 [-] Stopping factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x1c8f368>
2014-08-11 08:41:11+0200 [-] Main loop terminated.
2014-08-11 08:41:11+0200 [-] Server Shut Down.
2014-08-11 08:41:13+0200 [-] Log opened.
2014-08-11 08:41:13+0200 [-] twistd 12.0.0 (/usr/bin/python 2.7.3) starting up.
2014-08-11 08:41:13+0200 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2014-08-11 08:41:13+0200 [-] DelimitedBashReceiverFactory (TLS) starting on 789
2014-08-11 08:41:13+0200 [-] Starting factory <epoptes.daemon.bashplex.DelimitedBashReceiverFactory instance at 0x2ab72d8>
2014-08-11 08:41:13+0200 [-] GUIFactory starting on '/var/run/epoptes/epoptes.socket'
2014-08-11 08:41:13+0200 [-] Starting factory <epoptes.daemon.guiplex.GUIFactory instance at 0x2ab73f8>
2014-08-11 08:41:22+0200 [epoptes.daemon.guiplex.GUIFactory] GUI connection established (HOST:UNIXAddress('/var/run/epoptes/epoptes.socket') PEER:UNIXAddress(''))

Launching a "service epoptes restart" doesn't resolve the problem (can't view thumbs)

New installation => new epoptes key.
Did you transfer the new key to the clients?
http://www.epoptes.org/installation

~$ sudo ltsp-chroot -m epoptes-client -c
connect: Connection refused
connect:errno=111
epoptes-client ERROR: Failed to fetch certificate from localhost:789

Anyway, after purge, I use the following bash script to automate installation/configuration; perhaps is it wrong?

sudo apt-get install epoptes
sudo ltsp-chroot -m apt-get install epoptes-client
sudo ltsp-chroot -m epoptes-client -c
sudo update-rc.d -f epoptes remove
sudo update-rc.d epoptes default 30 70
echo 'SOCKET_GROUP=teachers' | sudo tee --append /etc/default/epoptes
sudo service epoptes restart

Following it is the output of above script:

$ sh epoptes.sh
Lettura elenco dei pacchetti... Fatto
Generazione albero delle dipendenze
Lettura informazioni sullo stato... Fatto
I seguenti pacchetti NUOVI saranno installati:
  epoptes
0 aggiornati, 1 installati, 0 da rimuovere e 0 non aggiornati.
È necessario scaricare 0 B/254 kB di archivi.
Dopo quest'operazione, verranno occupati 1521 kB di spazio su disco.
Selezionato il pacchetto epoptes non precedentemente selezionato.
(Lettura del database... 248923 file e directory attualmente installati.)
Estrazione di epoptes (da .../epoptes_0.5.6-1_all.deb)...
Elaborazione dei trigger per python-twisted-core...
Elaborazione dei trigger per man-db...
Elaborazione dei trigger per hicolor-icon-theme...
Elaborazione dei trigger per desktop-file-utils...
Elaborazione dei trigger per gnome-menus...
Elaborazione dei trigger per readahead-fedora...
Configurazione di epoptes (0.5.6-1)...
Aggiunta del gruppo «epoptes» (GID 137) ...
Fatto.
Generating a 1024 bit RSA private key
.........++++++
....++++++
writing new private key to '/etc/epoptes/server.key'
-----

A new OpenSSL certificate has been generated for epoptes.
Please ensure that you transfer /etc/epoptes/server.crt
to your clients by issuing `epoptes-client -c` from your
regular workstations or from your LTSP chroots.
[ ok ] Starting the epoptes daemon:.
Elaborazione dei trigger per python-twisted-core...
Elaborazione dei trigger per readahead-fedora...
[master 7ee8a67] committing changes in /etc after apt run
 Author: frank <email address hidden>
 16 files changed, 109 insertions(+), 2 deletions(-)
 create mode 100644 default/epoptes
 create mode 100644 epoptes/server.crt
 create mode 100644 epoptes/server.key
 create mode 100755 init.d/epoptes
 create mode 120000 rc0.d/K01epoptes
 create mode 120000 rc1.d/K01epoptes
 create mode 120000 rc2.d/S02epoptes
 create mode 120000 rc3.d/S02epoptes
 create mode 120000 rc4.d/S02epoptes
 create mode 120000 rc5.d/S02epoptes
 create mode 120000 rc6.d/K01epoptes
Lettura elenco dei pacchetti... Fatto
Generazione albero delle dipendenze
Lettura informazioni sullo stato... Fatto
epoptes-client è già alla versione più recente.
0 aggiornati, 0 installati, 0 da rimuovere e 0 non aggiornati.
depth=0 C = AU, ST = Some-State, O = Internet Widgits Pty Ltd
verify error:num=18:self signed certificate
verify return:1
depth=0 C = AU, ST = Some-State, O = Internet Widgits Pty Ltd
verify return:1
DONE
Successfully fetched certificate from localhost:789
update-rc.d: using dependency based boot sequencing
update-rc.d: using dependency based boot sequencing
usage: update-rc.d [-n] [-f] <basename> remove
       update-rc.d [-n] <basename> defaults [NN | SS KK]
       update-rc.d [-n] <basename> start|stop NN runlvl [runlvl] [...] .
       update-rc.d [-n] <basename> disable|enable [S|2|3|4|5]
  -n: not really
  -f: force

The disable|enable API is not stable and might change in the future.
SOCKET_GROUP=teachers
[ ok ] Stopping the epoptes daemon:.
[ ok ] Starting the epoptes daemon:.

In comment #12, you're mentioning:
 connect: Connection refused

In comment #14, you're mentioning:
 Successfully fetched certificate from localhost:789

Those don't match.

After comment #14, did you run ltsp-update-image, and did you reboot the clients?
You can also try IRC for real-time support:
http://webchat.freenode.net/?nick=epoptes_user.&channels=ltsp&prompt=1

With a fresh installation (default wheezy rep: 0.5.6) and workaround:

sudo update-rc.d -f epoptes remove
sudo update-rc.d epoptes default 30 70

seems to work fine so far

epoptes 0.5.6-1
debian-edu 7.6 (LDAP users)
----
Also after a fresh installation, randomly, epopses refuses to work. Same error:

Connection with epoptes failed:
An error occurred while connecting: 2: File o directory non esistente.

I installed it as follows:

sudo apt-get install -y epoptes
sudo ltsp-chroot -m apt-get install -y epoptes-client
sudo ltsp-chroot -m epoptes-client -c
sudo update-rc.d -f epoptes remove
sudo update-rc.d epoptes defaults 30 70
echo 'SOCKET_GROUP=teachers' | sudo tee --append /etc/default/epoptes
sudo service epoptes restart

If I launch a service restart, then it starts but I can't view thumbs of connected clients.

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