Add a Django command to fully rebuild the LDAP

CHANGELOG.md

@@ -103,14 +103,7 @@ After this modification you need to:
 * Double-check your defined groups' unix-name only contain small letters 
 * Run the following commands to rebuild your ldap's groups:
   ```shell
-  # In the LDAP shell :
-  ou=groups,ou=posix > rm *
-  ```
-  ```python
-  # In the Django shell
-  >>> from users.model import ListRight
-  >>> for lr in ListRight.objects.all():
-  ...     lr.ldap_sync()
+  python3 manage.py ldap_rebuild
   ```
 
 * You may need to force your nslcd cache to be reloaded on some servers (else you will have to wait for the cache to be refreshed):

users/management/commands/ldap_rebuild.py

@@ -0,0 +1,98 @@
+# Copyright © 2018 Maël Kervella
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+import subprocess
+from base64 import decodebytes
+
+from django.core.management.base import BaseCommand, CommandError
+from django.conf import settings
+
+from users.models import User, ListRight
+
+
+def flush_ldap(binddn, bindpass, server, usersdn, groupsdn):
+    """
+    Perform the python (and more understandable) equivalent of the following commands:
+
+    ldapsearch -A -s one -D $binddn -w $bindpass -H $server -b $usersdn dn \
+            | grep "dn: " | sed -e 's/dn: //g' \
+            | ldapdelete -v -D $binddn -w $bindpass -H $server --
+    ldapsearch -A -s one -D $binddn -w $bindpass -H $server -b $usersdn dn \
+            | grep "dn:: " | sed -e 's/dn:: //g' \
+            | while read x; do echo "$x" | base64 -d; echo ""; done \
+            | ldapdelete -v -D $binddn -w $bindpass -H $server --
+    ldapsearch -A -s one -D $binddn -w $bindpass -H $server -b $groupsdn dn \
+            | grep "dn: " | sed -e 's/dn: //g' \
+            | ldapdelete -v -D $binddn -w $bindpass -H $server --
+    ldapsearch -A -s one -D $binddn -w $bindpass -H $server -b $groupsdn dn \
+            | grep "dn:: " | sed -e 's/dn:: //g' \
+            | while read x; do echo "$x" | base64 -d; echo ""; done \
+            | ldapdelete -v -D $binddn -w $bindpass -H $server --
+    """
+
+    to_remove = []
+
+    for lookup in (usersdn, groupsdn):
+        search_cmd = [
+            'ldapsearch',
+            '-A',
+            '-s', 'one',
+            '-D', binddn,
+            '-w', bindpass,
+            '-H', server,
+            '-b', lookup,
+            'dn'
+        ]
+        for line in subprocess.check_output(search_cmd).split(b'\n'):
+            if line.startswith(b'dn: '):
+                to_remove.append(line[len(b'dn: '):])
+            elif line.startswith(b'dn:: '):
+                # Non ASCII value ares are base64-encoded
+                to_remove.append(decodebytes(line[len(b'dn:: '):]))
+
+    delete_cmd = [
+        'ldapdelete',
+        '-D', binddn,
+        '-w', bindpass,
+        '-H', server
+    ] + to_remove
+    subprocess.check_call(delete_cmd)
+
+
+def sync_ldap():
+    """Syncrhonize the whole LDAP with the DB."""
+    for u in User.objects.all():
+        u.ldap_sync()
+    for lr in ListRight.objects.all():
+        lr.ldap_sync()
+
+
+class Command(BaseCommand):
+    help = ('Destroy the current LDAP data and rebuild it from the DB data. '
+            'Use with caution.')
+
+    def handle(self, *args, **options):
+
+        usersdn = settings.LDAP['base_user_dn']
+        groupsdn = settings.LDAP['base_usergroup_dn']
+        binddn = settings.DATABASES['ldap']['USER']
+        bindpass = settings.DATABASES['ldap']['PASSWORD']
+        server = settings.DATABASES['ldap']['NAME']
+
+        flush_ldap(binddn, bindpass, server, usersdn, groupsdn)
+        self.stdout.write("LDAP emptied")
+        sync_ldap()
+        self.stdout.write("LDAP rebuilt")