[utils/ldapcertfs] Fonction wrappant les appels à ldap

Cache + gestion d'exception

utils/ldapcertfs.py

@@ -44,6 +44,7 @@ import os
 import sys
 import ssl
 import stat
+import ldap
 import time
 import fuse
 import errno
@@ -59,7 +60,7 @@ fuse.fuse_python_api = (0, 2)
 
 import logging
 LOG_FILENAME = 'ldapcertfs.log'
-logging.basicConfig(filename=LOG_FILENAME,level=logging.DEBUG)
+logging.basicConfig(filename=LOG_FILENAME,level=logging.WARNING)
 
 
 CACHE = {}
@@ -81,7 +82,7 @@ def get_from_cache(key, now=None, expire=CACHE_TIMEOUT):
         now = time.time()
     if key in CACHE:
         (ts, v) = CACHE[key]
-        if now - ts < expire:
+        if now - ts < expire or expire < 0:
             return v
         else:
             raise ValueError("Expired")
@@ -172,13 +173,39 @@ class LdapCertFS(fuse.Fuse):
         self._storage = {}
         self.passphrase = {}
 
-    def search_cache(self, filter, **kwargs):
+    def _func_cache(self, func, *args, **kwargs):
+        rec = kwargs.pop('rec', False)
+        kwargs_l = ["%s=%s" % kv for kv in kwargs.items()]
+        kwargs_l.sort()
+        serial = "%s(%s,%s)" % (func.__name__, ", ".join(args), ", ".join(kwargs_l))
         try:
-            return get_from_cache(filter)
+            return get_from_cache(serial)
         except ValueError:
-            objects = self.conn.search(filter, **kwargs)
-            set_to_cache(filter, objects)
-            return objects
+            try:
+                objects = func(*args, **kwargs)
+                set_to_cache(serial, objects)
+                return objects
+            except ldap.SERVER_DOWN:
+                try:
+                    self.conn = lc_ldap.shortcuts.lc_ldap_readonly()
+                    if not rec:
+                        logger.warning("[ldapcertfs] ldap down, retrying")
+                        kwargs['rec'] = rec
+                        self.func_cache(func, *args, **kwargs)
+                except Exception as e:
+                    logger.error("[ldapcertfs] uncaught exception %r" % e)
+                # Si le serveur est down on essaye de fournir un ancienne valeur du cache
+                try:
+                    return get_from_cache(serial, expire=-1)
+                except ValueError:
+                    logger.critical("[ldapcertfs] fail to return a valid result, I will probably crash next to this")
+                    return []
+
+    def search_cache(self, filter, **kwargs):
+        return self._func_cache(self.conn.search, filter, **kwargs)
+
+    def get_local_machines(self):
+        return self._func_cache(self.conn.get_local_machines)
 
     def make_root(self):
         self._storage['/'] = Item(0755 | stat.S_IFDIR, self.uid, self.gid)
@@ -187,7 +214,7 @@ class LdapCertFS(fuse.Fuse):
         elif self.ldap_filter:
             machines = self.search_cache("(&(%s)(mid=*))" % self.ldap_filter, sizelimit=8000)
         else:
-            machines = self.conn.get_local_machines()
+            machines = self.get_local_machines()
         for machine in machines:
             if not machine.certificats():
                 continue