Issue 1094 - Generate update manifests on the update server

modules/updateserver/templates/update_update_manifests.erb

Index: modules/updateserver/templates/update_update_manifests.erb
===================================================================
new file mode 100644
--- /dev/null
+++ b/modules/updateserver/templates/update_update_manifests.erb
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+run_file="/var/run/update_update_manifests"
+
+if [[ -f $run_file ]]; then
+    exit 0

[Wladimir Palant, 2014/07/25 09:50:11]

What if this script crashes and doesn't remove the file?

Please use a standard solution, e.g. the daemon package
(http://libslack.org/daemon/manpages/daemon.1.html).

[Felix Dahlke, 2014/07/25 10:31:15]

Using flock now, are you happy with that? It'll handle crashes.

[Wladimir Palant, 2014/07/25 11:11:02]

I'd really prefer a standardized solution that would keep the complexity out of
our code.

[Felix Dahlke, 2014/07/25 14:17:56]

I've looked into daemon, but I don't like the fact that we have to remember to
call the script with it (e.g. when regenerating update manifests manually). If
the script guarantees mutual exclusion itself, nothing can go wrong.

It seems that flock is the standarised solution for having a script run mutually
exclusive - it adds only 3 lines to the script and doesn't require additional
packages.

+fi
+
+echo "$$" >> "$run_file"
+
+<% repositories_to_sync.each do |repository| %>
+hg pull -q -u -R <%= base_dir %>/<%= repository %>

[Wladimir Palant, 2014/07/25 09:50:11]

Updating is unnecessary, the scripts work with the repository data directly
rather than the working directory. *If* you choose to update, you should do it
with -r default and --check, see filtermaster module.

[Felix Dahlke, 2014/07/25 10:31:15]

Done.

+<% end %>
+
+export PYTHONPATH=/opt/sitescripts
+python -m sitescripts.extensions.bin.updateUpdateManifests

[Wladimir Palant, 2014/07/25 09:50:11]

No need to export the variable if it is only used by a single command:

PYTHONPATH=/opt/sitescripts python -m ...

[Felix Dahlke, 2014/07/25 10:31:15]

It's shorter that way, I try to stick to 80 chars.

+
+rm -f "$run_file"