[FIX] db dump: report errors due to missing password + pass PGPASSWORD even on Unix

Even on Unix systems the PGPASSWORD env var
is necessary when Postgres is configured to
deny unix socket connections or to require
a password anyway. This avoids asking admins
to manually create a ~/.pgpass file in order
to use the dump/restore tools.
Also did some cleanup to ensure the PGPASSWORD
var is removed from the environment as soon
as the operation is done.

lp bug: https://launchpad.net/bugs/790164 fixed
lp bug: https://launchpad.net/bugs/919100 fixed

bzr revid: odo@openerp.com-20120131110849-tji6ipjovxc9oi4v

openerp/service/web_services.py

@@ -192,20 +192,24 @@ class db(netsvc.ExportService):
             cr.close()
         return True
 
+
     def _set_pg_psw_env_var(self):
-        if os.name == 'nt' and not os.environ.get('PGPASSWORD', ''):
+        # see http://www.postgresql.org/docs/8.4/static/libpq-pgpass.html
+        # FIXME: This is not thread-safe, and should never be enabled for
+        # SaaS (giving SaaS users the super-admin password is not a good idea
+        # anyway)
+        if tools.config['db_password'] and not os.environ.get('PGPASSWORD', ''):
             os.environ['PGPASSWORD'] = tools.config['db_password']
             self._pg_psw_env_var_is_set = True
 
     def _unset_pg_psw_env_var(self):
-        if os.name == 'nt' and self._pg_psw_env_var_is_set:
+        if self._pg_psw_env_var_is_set:
             os.environ['PGPASSWORD'] = ''
 
     def exp_dump(self, db_name):
         logger = netsvc.Logger()
-
+        try:
             self._set_pg_psw_env_var()
-
             cmd = ['pg_dump', '--format=c', '--no-owner']
             if tools.config['db_user']:
                 cmd.append('--username=' + tools.config['db_user'])
@@ -219,20 +223,24 @@ class db(netsvc.ExportService):
             stdin.close()
             data = stdout.read()
             res = stdout.close()
-        if res:
+    
+            if not data or res:
                 logger.notifyChannel("web-services", netsvc.LOG_ERROR,
-                    'DUMP DB: %s failed\n%s' % (db_name, data))
+                        'DUMP DB: %s failed! Please verify the configuration of the database password on the server. '\
+                        'It should be provided as a -w <PASSWD> command-line option, or as `db_password` in the '\
+                        'server configuration file.\n %s'  % (db_name, data))
                 raise Exception, "Couldn't dump database"
             logger.notifyChannel("web-services", netsvc.LOG_INFO,
-                'DUMP DB: %s' % (db_name))
-
-        self._unset_pg_psw_env_var()
+                    'DUMP DB successful: %s' % (db_name))
     
             return base64.encodestring(data)
+        finally:
+            self._unset_pg_psw_env_var()
 
     def exp_restore(self, db_name, data):
         logger = netsvc.Logger()
 
+        try:
             self._set_pg_psw_env_var()
 
             if self.exp_db_exist(db_name):
@@ -269,9 +277,9 @@ class db(netsvc.ExportService):
             logger.notifyChannel("web-services", netsvc.LOG_INFO,
                     'RESTORE DB: %s' % (db_name))
 
-        self._unset_pg_psw_env_var()
-
             return True
+        finally:
+            self._unset_pg_psw_env_var()
 
     def exp_rename(self, old_name, new_name):
         openerp.modules.registry.RegistryManager.delete(old_name)