theia: support moving file on different filesystem during resiliency export

Due to disk usage on my production server, I had to move the theia's
backup to a different file system. I bind mount this other fs on:

slappart0/srv/backup/theia

Mounting on "slappart0/srv/backup" would make logrogate
complain (logrotate is used in the "backup" cron, triggering the
resiliency process). So "slappart0/srv/backup/theia" was the 2nd best
idea. Unfortunately for my case, os.rename raises if the src and dest
filesystems are different, as it os.rename guarantees the atomicity of
the operation. As atomicity is not that important for copying the
signature file, it can be replaced by shutil.move.

software/theia/theia_export.py

@@ -2,6 +2,7 @@ import argparse
 import glob
 import itertools
 import os
+import shutil
 import sys
 import time
 import traceback
@@ -92,7 +93,7 @@ class TheiaExport(object):
     with open(tmpfile, 'w') as f:
       for s in signatures:
         f.write(s + '\n')
-    os.rename(tmpfile, signaturefile)
+    shutil.move(tmpfile, signaturefile)
 
   def sign_root(self):
     signaturefile = os.path.join(self.backup_dir, 'backup.signature')

[Romain Courteaud]

@Nicolas it seems you forgot to update one md5sum

[Nicolas Wavrant]

Thank you Romain ! I pushed a fixup:

00563b19