Merge lp:~oiteam/epoptes/auto-reconnect into lp:~epoptes/epoptes/exported-translations

[Laércio de Sousa]

Re-proposing this merge after some rework following Alkis advices (via IRC).

[lp:~oiteam/epoptes/auto-reconnect]

391. By Laércio de Sousa on 2015-10-06

Rename variables to avoid potential conflicts with ones set by socat itself.

392. By Laércio de Sousa on 2015-10-23

Reintroduce asking to systemd-logind if current session is closing, as epoptes-client may not receive a SIGTERM from session manager on logout.

[Alkis Georgopoulos (alkisg)]

Hi Laércio,

thanks for the patch, but it was rather harder than a loop, so I'll close this branch.

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.

Please comment on if the above commits work for you!

review: Disapprove

Unmerged revisions

392. By Laércio de Sousa on 2015-10-23

Reintroduce asking to systemd-logind if current session is closing, as epoptes-client may not receive a SIGTERM from session manager on logout.

391. By Laércio de Sousa on 2015-10-06

Rename variables to avoid potential conflicts with ones set by socat itself.

390. By Laércio de Sousa on 2015-10-05

Merge with trunk

389. By Laércio de Sousa on 2015-10-05

Update auto-reconnect heuristic to terminate gracefully when logind session terminates, but also deal with non-systemd contexts.

388. By Laércio de Sousa on 2015-10-02

Revert revision 387. We'll follow another systemd-independent approach.

387. By Laércio de Sousa on 2013-12-19

Stop trying to reconnect if systemd-logind session is closing

386. By Laércio de Sousa on 2013-03-22

Keep reconnecting even if socat ends unexpectedly (exit code != 0).

385. By Laércio de Sousa on 2013-03-14

Add a "sleep 1" inside while loops, just for precaution.

384. By Laércio de Sousa on 2013-03-13

Restore original behaviour (no auto-reconnect) for thin/fat clients only.

383. By Laércio de Sousa on 2013-03-08

Fix coding style consistency

=== modified file 'epoptes-client/epoptes-client'
--- epoptes-client/epoptes-client	2015-10-06 19:14:31 +0000
+++ epoptes-client/epoptes-client	2015-10-23 18:07:51 +0000
@@ -230,15 +230,52 @@
     cert_param="verify=0"
 fi
 
-# Connect to the server, or keep retrying until the server gets online
-# (for standalone workstations booted before the server).
 if [ -s /etc/epoptes/server.crt ] || [ "$cert_param" = "verify=0" ]; then
-    exec socat openssl-connect:$SERVER:$PORT,$cert_param,interval=60,forever EXEC:"$cmdline"
+    socat_prefix="openssl-connect"
+    socat_cert=",$cert_param"
+    socat_suffix=""
 elif [ -f /etc/epoptes/server.crt ]; then
-   exec socat tcp:$SERVER:$PORT,interval=60,forever EXEC:"$cmdline",nofork
+    socat_prefix="tcp"
+    socat_cert=""
+    socat_suffix=",nofork"
 else
     die "
 The epoptes certificate file, /etc/epoptes/server.crt, doesn't exist.
 You can fetch the server certificate by running:
 $0 -c"
+    exit 1
+fi
+
+# Connect to the server, or keep retrying until the server gets online
+# (for standalone workstations booted before the server).
+# Uses SIGTERM-propagation scheme as proposed in
+# http://veithen.github.io/2014/11/16/sigterm-propagation.html
+if [ "$TYPE" = "standalone" ]; then
+    trap 'kill -TERM $socat_pid; KEEP_ALIVE=false' TERM INT
+    KEEP_ALIVE=true
+
+    while $KEEP_ALIVE; do
+        socat ${socat_prefix}:${SERVER}:${PORT}${socat_cert},interval=60,forever EXEC:"$cmdline"${socat_suffix} &
+        socat_pid=$!
+        wait $socat_pid
+        trap - TERM INT
+        wait $socat_pid
+        socat_ret=$?
+
+        # Just in case we don't receive a SIGTERM
+        # from session manager on logout,
+        # ask systemd-logind (if available)
+        # if we can quit safely.
+        [ "$(loginctl show-session -p State $XDG_SESSION_ID | cut -d= -f2)" = "closing" ] && KEEP_ALIVE=false
+
+        if [ $socat_ret -eq 0 ]; then
+            socat_message="Connection lost"
+        else
+            socat_message="WARNING: socat exited with unexpected code $socat_ret"
+        fi
+
+        $KEEP_ALIVE && log_begin_msg "${socat_message}. Epoptes-client reconnecting to $SERVER:$PORT..."
+    done
+else
+    exec socat ${socat_prefix}:${SERVER}:${PORT}${socat_cert},interval=60,forever EXEC:"$cmdline"${socat_suffix}
 fi