automatic reconnect of client if server went away

When epoptes was first developed, it targeted LTSP netbooted computer labs, where the clients would crash anyway if the network connection was ever lost. So the reconnection feature was skipped in order to minimize RAM usage for thin clients.

It will be implemented in a future version, since now epoptes also targets non LTSP installations as well.

Is there some script I can place on the clients that will check to see if epoptes is connected, and then reconnect if it is not?

We want to solve this in a good way that's why we're postponing it until the networking backend is redesigned.

In the meantime, you could try editing /usr/sbin/epoptes-client,
and replacing:
    exec socat openssl-connect:$SERVER:$PORT,$cert_param,interval=60,forever EXEC:"$cmdline"
with:
   while ! socat openssl-connect:$SERVER:$PORT,$cert_param,interval=60,forever EXEC:"$cmdline"; do sleep 1; done

and:
    exec socat tcp:$SERVER:$PORT,interval=60,forever EXEC:"$cmdline",nofork
with:
    while ! socat tcp:$SERVER:$PORT,interval=60,forever EXEC:"$cmdline",nofork; do sleep 1; done

That might work but I haven't tested it.

Alkis,

In my tests (server running Ubuntu 12.04;, clients running Ubuntu 10.04), your solution didn't work.

Fortunately, I rapidly realized that socat exits with code 0 when I disconnect the server, thus I removed the "!"s in while clauses. Now the automatic reconnection works.

Thanks a lot!

I've just uploaded a new branch with this solution, for anyone interested.

lp:~oiteam/epoptes/auto-reconnect

I'm testing auto-reconnect branch in three different situations:

- server reboots
- server disconnects (loses IP)
- client disconnects

In all cases, I get auto reconnection in almost all tries. In some tries, however, a given client reconnects, but does not show thumbnails (in other words, EM_SYSTEM reconnects, but EM_SESSION doesn't).

Still working on it...

Good work, guys...keep it up.

I'm working with a couple of mobile labs full of laptops. This is my biggest problem. Whenever students close the laptop the connection is lost and does not re-establish automatically. I've also experienced cases where it seems like the connection just fails for other reasons. I am really looking forward to having the reconnect work well.

What are the chances this will land in Epoptes for 12.04?

Dave,

If you wanna try, you can download the epoptes-client script from auto-reconnect branch and put it in folder /usr/sbin in your clients.

http://bazaar.launchpad.net/~oiteam/epoptes/auto-reconnect/view/head:/epoptes-client/epoptes-client

I maintain a PPA with daily updates of Epoptes code, plus some branches I maintain for multiseat purposes (intended for use in computers of project ProInfo, Brazil). The auto-reconnect branch is also included in this PPA.

This PPA contains packages for all supported Ubuntu releases (lucid, precise, quantal, raring).

ppa:oiteam/epoptes-daily

Should't this branch be merged to epoptes trunk? I have also tested it and works just fine. it is far better now with the reconnection of the clients (when the server looses connection to the network or just reboots)

hello I'm in trouble with auto -reconnect customers 'm trying to put the link of the script :

http://bazaar.launchpad.net/~oiteam/epoptes/auto-reconnect/annotate/head:/epoptes-client/epoptes-client

crontab but it is not working because the script needs of the active terminal session would help me because I am new to linux environment.

Sorry for the English because it was translated with google translator

Hi there!

Instead of hacking /usr/sbin/epoptes-client, I've written a wrapper script to be executed instead in /etc/xdg/autostart/epoptes-client.desktop. Here's the code (tested on Xubuntu 15.04):

#!/bin/sh

old_hostname=$(hostname)

[ -x /usr/bin/nm-online ] && nm-online --timeout=600

until [ "$State" = "closing" ]
do
    new_hostname=$(hostname)

    if [ "${new_hostname}" != "${old_hostname}" ]
    then
        cookie=$(xauth list ${old_hostname}/unix${DISPLAY} | cut -f5 -d' ')
        xauth add "${new_hostname}/unix${DISPLAY}" "MIT-MAGIC-COOKIE-1" ${cookie}
        old_hostname=${new_hostname}
    fi

    epoptes-client
    eval $(loginctl show-session ${XDG_SESSION_ID} | grep "State")
done

Laércio de Sousa (lbssousa) how did you run the script? Where did you put it?

I have the same problem using 32 pc using linux mint xfce 17.2 in a lab, the clients disconects...

Hi guys,

Reconnections were implemented in:
http://bazaar.launchpad.net/~epoptes/epoptes/trunk/revision/458

Keeping the connections were implemented in:
http://bazaar.launchpad.net/~epoptes/epoptes/trunk/revision/457

And there will be another commit for reconnecting the GUI to the epoptes service.

There are builds available in the epoptes daily builds ppa.

Please comment on if the above commits work for you!

I installed from epoptes daily builds ppa, (epoptes_0.5.8+bzr461+oi3+201511230531~ubuntu14.04.1_all.deb) in the server and the client and the reconnection works very well.

But when I click on the information button, this does not work and the terminal shows me this error:

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/epoptes/ui/gui.py", line 474, in on_tb_client_properties_clicked
    dlg = ClientInformation(self.getSelectedClients(), self.daemon.command)
  File "/usr/lib/python2.7/dist-packages/epoptes/ui/client_information.py", line 60, in __init__
    uname, realname = inst.users[client[C_SESSION_HANDLE]].values()
ValueError: too many values to unpack

I assume that is because in the source code there are pieces of code for multiseat environments, for example I found it in /usr/lib/python2.7/dist-packages/epoptes/core/structs.py:

   def add_user(self, username, realname, seat, handle):
        self.users[handle] = {'uname' : username, 'rname' : realname, 'seat' : seat}

@ippsatsi, the package version number suggests that you used this PPA:
https://launchpad.net/~oiteam/+archive/ubuntu/epoptes

AFAIK this is Laércio's PPA, it's not the "official" one where the epoptes developers publish our proposed versions:
https://code.launchpad.net/~epoptes/+archive/ubuntu/proposed

Remove it from your sources (sudo rm /etc/apt/sources.list.d/epoptes*), and try this instead:
sudo add-apt-repository ppa:epoptes/proposed
sudo apt-get update
sudo apt-get dist-upgrade

In the end, verify that you have this version installed:
0.5.8-1+r462~ubuntu14.04.1

Thanks, i'll try.

Fix released in epoptes 0.5.9.