From dde98c235c4438e2eef37263e446b14bc369efb5 Mon Sep 17 00:00:00 2001
From: Antoine Nguyen <tonio@ngyn.org>
Date: Thu, 29 Jan 2015 21:06:15 +0100
Subject: [PATCH] WIP: change the way extensions initial data is loaded.

---
 modoboa/core/__init__.py                      | 10 ++++
 modoboa/core/commands/deploy.py               | 13 ++---
 .../core/commands/templates/settings.py.tpl   |  4 --
 modoboa/core/extensions.py                    |  4 ++
 .../management/commands/load_initial_data.py  | 51 +++++++++++++++++++
 ..._extension.py => 0002_delete_extension.py} |  2 +-
 .../core/migrations/0002_load_initial_data.py | 26 ----------
 .../migrations/0002_load_initial_data.py      | 43 ----------------
 modoboa/extensions/admin/modo_extension.py    | 24 +++++++++
 .../extensions/limits/general_callbacks.py    | 20 ++++++++
 .../migrations/0002_load_initial_data.py      | 23 +--------
 modoboa/extensions/limits/modo_extension.py   |  8 +++
 .../general_callbacks.py                      | 27 +++++++++-
 .../migrations/0002_load_initial_data.py      | 23 ---------
 .../postfix_relay_domains/modo_extension.py   | 12 -----
 .../extensions/radicale/general_callbacks.py  | 20 ++++++++
 .../migrations/0002_load_initial_data.py      | 37 --------------
 modoboa/lib/migration_tools.py                | 18 -------
 modoboa/lib/permissions.py                    | 16 ++++++
 19 files changed, 186 insertions(+), 195 deletions(-)
 create mode 100644 modoboa/core/management/commands/load_initial_data.py
 rename modoboa/core/migrations/{0003_delete_extension.py => 0002_delete_extension.py} (86%)
 delete mode 100644 modoboa/core/migrations/0002_load_initial_data.py
 delete mode 100644 modoboa/extensions/admin/migrations/0002_load_initial_data.py
 delete mode 100644 modoboa/extensions/radicale/migrations/0002_load_initial_data.py
 delete mode 100644 modoboa/lib/migration_tools.py

diff --git a/modoboa/core/__init__.py b/modoboa/core/__init__.py
index 8a03f0e5d..e31c299f1 100644
--- a/modoboa/core/__init__.py
+++ b/modoboa/core/__init__.py
@@ -18,6 +18,7 @@ BASE_EVENTS = [
     "ExtraAccountActions",
     "RoleChanged",
     "GetExtraRoles",
+    "GetExtraRolePermissions",
     "PasswordChange",
     "UserCanSetRole",
 
@@ -41,6 +42,15 @@ BASE_EVENTS = [
     "SaveExtraFormFields",
 ]
 
+PERMISSIONS = {
+    "DomainAdmins": [
+        ["core", "user", "add_user"],
+        ["core", "user", "change_user"],
+        ["core", "user", "delete_user"],
+    ],
+    "SimpleUsers": []
+}
+
 
 def load_core_settings():
     """Load core settings.
diff --git a/modoboa/core/commands/deploy.py b/modoboa/core/commands/deploy.py
index 4e77afc5d..4bcbd7e9a 100644
--- a/modoboa/core/commands/deploy.py
+++ b/modoboa/core/commands/deploy.py
@@ -6,6 +6,7 @@ import sys
 
 import subprocess
 
+import django
 from django.core import management
 from django.template import Context, Template
 
@@ -138,6 +139,7 @@ class DeployCommand(Command):
         return info
 
     def handle(self, parsed_args):
+        django.setup()
         management.call_command(
             'startproject', parsed_args.name, verbosity=False
         )
@@ -215,17 +217,10 @@ class DeployCommand(Command):
         os.unlink("%s/settings.pyc" % path)
         if parsed_args.dbaction == "install":
             self._exec_django_command(
-                "syncdb", parsed_args.name, '--noinput'
-            )
-            exec_cmd('sed -ri "s|^#(\s+\'south)|\\1|" %s/settings.py' % path)
-            self._exec_django_command(
-                "syncdb", parsed_args.name,
+                "migrate", parsed_args.name, '--noinput'
             )
             self._exec_django_command(
-                'migrate', parsed_args.name, '--fake'
-            )
-            self._exec_django_command(
-                "loaddata", parsed_args.name, 'initial_users.json'
+                "load_initial_data", parsed_args.name
             )
         elif parsed_args.dbaction == "upgrade":
             exec_cmd('sed -ri "s|^#(\s+\'south)|\\1|" %s/settings.py' % path)
diff --git a/modoboa/core/commands/templates/settings.py.tpl b/modoboa/core/commands/templates/settings.py.tpl
index aaf648741..2ba6dc86b 100644
--- a/modoboa/core/commands/templates/settings.py.tpl
+++ b/modoboa/core/commands/templates/settings.py.tpl
@@ -46,7 +46,6 @@ INSTALLED_APPS = (
     'django.contrib.messages',
     'django.contrib.sites',
     'django.contrib.staticfiles',
-#    'south',
     'reversion',
 )
 
@@ -150,9 +149,6 @@ STATICFILES_DIRS = (
 MEDIA_URL = '/media/'
 MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
 
-# South settings
-SOUTH_TESTS_MIGRATE = False
-
 # Modoboa settings
 #MODOBOA_CUSTOM_LOGO = os.path.join(MEDIA_URL, "custom_logo.png")
 
diff --git a/modoboa/core/extensions.py b/modoboa/core/extensions.py
index a67e3c04d..82e5fd30e 100644
--- a/modoboa/core/extensions.py
+++ b/modoboa/core/extensions.py
@@ -29,6 +29,10 @@ class ModoExtension(object):
             always_active=self.always_active
         )
 
+    def load_initial_data(self):
+        """Declare extension data in this method."""
+        pass
+
     def load(self):
         pass
 
diff --git a/modoboa/core/management/commands/load_initial_data.py b/modoboa/core/management/commands/load_initial_data.py
new file mode 100644
index 000000000..a42a99ef3
--- /dev/null
+++ b/modoboa/core/management/commands/load_initial_data.py
@@ -0,0 +1,51 @@
+"""A management command to load Modoboa initial data:
+
+* Create a default super admin if none exists
+* Create groups and permissions
+
+"""
+
+from django.contrib.auth.models import Group
+from django.core.management.base import BaseCommand
+
+from modoboa.core import PERMISSIONS
+from modoboa.core.extensions import exts_pool
+from modoboa.core.models import User, ObjectAccess
+from modoboa.lib import events
+from modoboa.lib.permissions import add_permissions_to_group
+from . import CloseConnectionMixin
+
+
+class Command(BaseCommand, CloseConnectionMixin):
+
+    """Command defintion."""
+
+    help = "Load Modoboa initial data"
+
+    def handle(self, *args, **options):
+        """Command entry point."""
+
+        if not User.objects.filter(pk=1, username="admin").exists():
+            admin = User(username="admin", is_superuser=True)
+            admin.set_password("password")
+            admin.save()
+            ObjectAccess.objects.create(
+                user=admin, content_object=admin, is_owner=True)
+
+        groups = PERMISSIONS.keys() + [
+            role[0] for role in events.raiseQueryEvent("GetExtraRoles")
+        ]
+        for groupname in groups:
+            group, created = Group.objects.get_or_create(name=groupname)
+            permissions = (
+                PERMISSIONS.get(groupname, []) +
+                events.raiseQueryEvent("GetExtraRolePermissions", groupname)
+            )
+            if not permissions:
+                continue
+            add_permissions_to_group(group, permissions)
+
+        exts_pool.load_all()
+        for extname in exts_pool.extensions.keys():
+            extension = exts_pool.get_extension(extname)
+            extension.load_initial_data()
diff --git a/modoboa/core/migrations/0003_delete_extension.py b/modoboa/core/migrations/0002_delete_extension.py
similarity index 86%
rename from modoboa/core/migrations/0003_delete_extension.py
rename to modoboa/core/migrations/0002_delete_extension.py
index 3b4dc989e..073ef44bb 100644
--- a/modoboa/core/migrations/0003_delete_extension.py
+++ b/modoboa/core/migrations/0002_delete_extension.py
@@ -7,7 +7,7 @@ from django.db import models, migrations
 class Migration(migrations.Migration):
 
     dependencies = [
-        ('core', '0002_load_initial_data'),
+        ('core', '0001_initial'),
     ]
 
     operations = [
diff --git a/modoboa/core/migrations/0002_load_initial_data.py b/modoboa/core/migrations/0002_load_initial_data.py
deleted file mode 100644
index 67be945f2..000000000
--- a/modoboa/core/migrations/0002_load_initial_data.py
+++ /dev/null
@@ -1,26 +0,0 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
-
-
-def load_initial_data(apps, schema_editor):
-    """Load initial data."""
-    User = apps.get_model("core", "User")
-    user = User(username="admin", is_superuser=True)
-    user.set_password("password")
-    user.save()
-
-    ObjectAccess = apps.get_model("core", "ObjectAccess")
-    ObjectAccess.objects.create(user=user, content_object=user, is_owner=True)
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('core', '0001_initial'),
-    ]
-
-    operations = [
-        migrations.RunPython(load_initial_data)
-    ]
diff --git a/modoboa/extensions/admin/migrations/0002_load_initial_data.py b/modoboa/extensions/admin/migrations/0002_load_initial_data.py
deleted file mode 100644
index 1f08a43c9..000000000
--- a/modoboa/extensions/admin/migrations/0002_load_initial_data.py
+++ /dev/null
@@ -1,43 +0,0 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
-
-from modoboa.lib.migration_tools import add_permissions_to_group
-
-PERMISSIONS = [
-    ["core", "user", "add_user"],
-    ["core", "user", "change_user"],
-    ["core", "user", "delete_user"],
-    ["admin", "domain", "view_domain"],
-    ["admin", "mailbox", "add_mailbox"],
-    ["admin", "mailbox", "change_mailbox"],
-    ["admin", "mailbox", "delete_mailbox"],
-    ["admin", "alias", "add_alias"],
-    ["admin", "alias", "change_alias"],
-    ["admin", "alias", "delete_alias"],
-    ["admin", "mailbox", "view_mailboxes"],
-    ["admin", "alias", "view_aliases"],
-    ["admin", "domainalias", "view_domainaliases"],
-    ["admin", "domainalias", "add_domainalias"],
-    ["admin", "domainalias", "change_domainalias"],
-    ["admin", "domainalias", "delete_domainalias"]
-]
-
-def load_initial_data(apps, schema_editor):
-    """Load initial data."""
-    Group = apps.get_model("auth", "Group")
-    dadmins = Group.objects.create(name="DomainAdmins")
-    add_permissions_to_group(apps, dadmins, PERMISSIONS)
-    Group.objects.create(name="SimpleUsers")
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('admin', '0001_initial'),
-    ]
-
-    operations = [
-        migrations.RunPython(load_initial_data)
-    ]
diff --git a/modoboa/extensions/admin/modo_extension.py b/modoboa/extensions/admin/modo_extension.py
index fdbd41c80..0b5687508 100644
--- a/modoboa/extensions/admin/modo_extension.py
+++ b/modoboa/extensions/admin/modo_extension.py
@@ -45,6 +45,24 @@ ADMIN_EVENTS = [
     "ImportObject"
 ]
 
+PERMISSIONS = {
+    "DomainAdmins": [
+        ["admin", "domain", "view_domain"],
+        ["admin", "mailbox", "add_mailbox"],
+        ["admin", "mailbox", "change_mailbox"],
+        ["admin", "mailbox", "delete_mailbox"],
+        ["admin", "alias", "add_alias"],
+        ["admin", "alias", "change_alias"],
+        ["admin", "alias", "delete_alias"],
+        ["admin", "mailbox", "view_mailboxes"],
+        ["admin", "alias", "view_aliases"],
+        ["admin", "domainalias", "view_domainaliases"],
+        ["admin", "domainalias", "add_domainalias"],
+        ["admin", "domainalias", "change_domainalias"],
+        ["admin", "domainalias", "delete_domainalias"]
+    ]
+}
+
 
 class AdminConsole(ModoExtension):
     name = "admin"
@@ -64,6 +82,12 @@ class AdminConsole(ModoExtension):
 exts_pool.register_extension(AdminConsole)
 
 
+@events.observe("GetExtraRolePermissions")
+def extra_permissions(rolename):
+    """Return extra permissions for :kw:`rolename`."""
+    return PERMISSIONS.get(rolename, [])
+
+
 @events.observe("ExtraUprefsRoutes")
 def extra_routes():
     from django.conf.urls import url
diff --git a/modoboa/extensions/limits/general_callbacks.py b/modoboa/extensions/limits/general_callbacks.py
index 66561368d..3f207eebc 100644
--- a/modoboa/extensions/limits/general_callbacks.py
+++ b/modoboa/extensions/limits/general_callbacks.py
@@ -2,11 +2,25 @@
 
 from django.utils.translation import ugettext as _
 
+from modoboa.core import PERMISSIONS as CORE_PERMS
+from modoboa.extensions.admin.modo_extension import PERMISSIONS as ADMIN_PERMS
 from modoboa.extensions.limits.forms import ResourcePoolForm
 from modoboa.extensions.limits.models import LimitTemplates
 from modoboa.lib import events
 
 
+PERMISSIONS = {
+    "Resellers": (
+        CORE_PERMS.get("DomainAdmins") +
+        ADMIN_PERMS.get("DomainAdmins") +
+        [["admin", "domain", "view_domains"],
+         ["admin", "domain", "add_domain"],
+         ["admin", "domain", "change_domain"],
+         ["admin", "domain", "delete_domain"]]
+    )
+}
+
+
 @events.observe("GetExtraRoles")
 def get_extra_roles(user):
     if user.is_superuser:
@@ -14,6 +28,12 @@ def get_extra_roles(user):
     return []
 
 
+@events.observe("GetExtraRolePermissions")
+def extra_permissions(rolename):
+    """Return extra permissions for Resellers."""
+    return PERMISSIONS.get(rolename, [])
+
+
 @events.observe("ExtraAdminContent")
 def display_pool_usage(user, target, currentpage):
     from django.template.loader import render_to_string
diff --git a/modoboa/extensions/limits/migrations/0002_load_initial_data.py b/modoboa/extensions/limits/migrations/0002_load_initial_data.py
index ef293c25b..eb51dcd1d 100644
--- a/modoboa/extensions/limits/migrations/0002_load_initial_data.py
+++ b/modoboa/extensions/limits/migrations/0002_load_initial_data.py
@@ -3,37 +3,18 @@ from __future__ import unicode_literals
 
 from django.db import models, migrations
 
-from modoboa.core.extensions import exts_pool
-from modoboa.lib.migration_tools import add_permissions_to_group
-from modoboa.extensions.limits.midels import LimitTemplates
+from modoboa.extensions.limits.models import LimitTemplates
 
 
 def load_initial_data(apps, schema_editor):
     """Load initial data."""
-    Group = apps.get_model("auth", "Group")
     User = apps.get_model("core", "User")
     LimitsPool = apps.get_model("limits", "LimitsPool")
     Limit = apps.get_model("limits", "Limit")
 
-    dagrp = Group.objects.get(name="DomainAdmins")
-    grp = Group(name="Resellers")
-    grp.save()
-    grp.permissions.add(*dagrp.permissions.all())
-    add_permissions_to_group(
-        apps, grp, [("admin", "domain", "view_domains"),
-                    ("admin", "domain", "add_domain"),
-                    ("admin", "domain", "change_domain"),
-                    ("admin", "domain", "delete_domain")]
-    )
-    if exts_pool.is_extension_installed(
-            "modoboa.extensions.postfix_relay_domains"):
-        from modoboa.extensions.postfix_relay_domains.modo_extension \
-            import RESELLERS_PERMISSIONS
-        add_permissions_to_group(apps, grp, RESELLERS_PERMISSIONS)
-
     for user in User.objects.filter(groups__name="DomainAdmins"):
         pool, created = LimitsPool.objects.get_or_create(user=user)
-        for tpl in LimitTemplates().templates():
+        for tpl in LimitTemplates().templates:
             Limit.objects.create(name=tpl[0], pool=pool, maxvalue=0)
 
 
diff --git a/modoboa/extensions/limits/modo_extension.py b/modoboa/extensions/limits/modo_extension.py
index f98433e30..2f1253ee2 100644
--- a/modoboa/extensions/limits/modo_extension.py
+++ b/modoboa/extensions/limits/modo_extension.py
@@ -8,6 +8,7 @@ from django.utils.translation import ugettext_lazy
 
 from modoboa.core.extensions import ModoExtension, exts_pool
 from modoboa.lib import events, parameters
+from .models import LimitsPool, Limit
 
 
 EVENTS = [
@@ -32,4 +33,11 @@ class Limits(ModoExtension):
         events.declare(EVENTS)
         from modoboa.extensions.limits import general_callbacks
 
+    def load_initial_data(self):
+        """Complete existing pools with new limits."""
+        new_limits = ["relay_domains_limit", "relay_domain_aliases_limit"]
+        for pool in LimitsPool.objects.all():
+            for lname in new_limits:
+                Limit.objects.get_or_create(name=lname, pool=pool, maxvalue=0)
+
 exts_pool.register_extension(Limits)
diff --git a/modoboa/extensions/postfix_relay_domains/general_callbacks.py b/modoboa/extensions/postfix_relay_domains/general_callbacks.py
index 404a4013b..34422c156 100644
--- a/modoboa/extensions/postfix_relay_domains/general_callbacks.py
+++ b/modoboa/extensions/postfix_relay_domains/general_callbacks.py
@@ -6,8 +6,33 @@ from django.db.models import Q
 from django.template import Template, Context
 from django.utils.translation import ugettext_lazy
 
-from .models import RelayDomain, RelayDomainAlias
+from modoboa.core.extensions import exts_pool
 from modoboa.lib import events
+from .models import RelayDomain, RelayDomainAlias
+
+PERMISSIONS = {
+    "Resellers": [
+        ("postfix_relay_domains", "relaydomain", "add_relaydomain"),
+        ("postfix_relay_domains", "relaydomain", "change_relaydomain"),
+        ("postfix_relay_domains", "relaydomain", "delete_relaydomain"),
+        ("postfix_relay_domains", "relaydomainalias", "add_relaydomainalias"),
+        ("postfix_relay_domains", "relaydomainalias",
+         "change_relaydomainalias"),
+        ("postfix_relay_domains", "relaydomainalias",
+         "delete_relaydomainalias"),
+        ("postfix_relay_domains", "service", "add_service"),
+        ("postfix_relay_domains", "service", "change_service"),
+        ("postfix_relay_domains", "service", "delete_service")
+    ]
+}
+
+
+@events.observe("GetExtraRolePermissions")
+def extra_permissions(rolename):
+    """Return extra permissions for Resellers."""
+    if not exts_pool.is_extension_installed("modoboa.extensions.limit"):
+        return []
+    return PERMISSIONS.get(rolename, [])
 
 
 @events.observe('GetStaticContent')
diff --git a/modoboa/extensions/postfix_relay_domains/migrations/0002_load_initial_data.py b/modoboa/extensions/postfix_relay_domains/migrations/0002_load_initial_data.py
index 4be3e1d02..cec56af50 100644
--- a/modoboa/extensions/postfix_relay_domains/migrations/0002_load_initial_data.py
+++ b/modoboa/extensions/postfix_relay_domains/migrations/0002_load_initial_data.py
@@ -3,11 +3,6 @@ from __future__ import unicode_literals
 
 from django.db import models, migrations
 
-from modoboa.core.extensions import exts_pool
-from modoboa.lib.migration_tools import add_permissions_to_group
-
-from ..modo_extension import RESELLERS_PERMISSIONS
-
 
 def load_initial_data(apps, schema_editor):
     """Load initial data."""
@@ -15,24 +10,6 @@ def load_initial_data(apps, schema_editor):
     for service_name in ['relay', 'smtp']:
         Service.objects.get_or_create(name=service_name)
 
-    if not exts_pool.is_extension_installed("modoboa.extensions.limits"):
-        return
-
-    Group = apps.get_model("auth", "Group")
-    LimitsPool = apps.get_model("limits", "LimitsPool")
-    Limit = apps.get_model("limits", "Limit")
-
-    # Add new limits to existing pools. Set maxvalue to 0 because we
-    # don't want to load the parameters module here...
-    new_limits = ["relay_domains_limit", "relay_domain_aliases_limit"]
-    for pool in LimitsPool.objects.all():
-        for lname in new_limits:
-            Limit.objects.create(name=lname, pool=pool, maxvalue=0)
-
-    # Add new permissions to the Resellers group.
-    grp = Group.objects.get(name='Resellers')
-    add_permissions_to_group(apps, grp, RESELLERS_PERMISSIONS)
-
 
 class Migration(migrations.Migration):
 
diff --git a/modoboa/extensions/postfix_relay_domains/modo_extension.py b/modoboa/extensions/postfix_relay_domains/modo_extension.py
index ed212771f..2fe412608 100644
--- a/modoboa/extensions/postfix_relay_domains/modo_extension.py
+++ b/modoboa/extensions/postfix_relay_domains/modo_extension.py
@@ -18,18 +18,6 @@ EXTENSION_EVENTS = [
     "FillRelayDomainInstances"
 ]
 
-RESELLERS_PERMISSIONS = [
-    ("postfix_relay_domains", "relaydomain", "add_relaydomain"),
-    ("postfix_relay_domains", "relaydomain", "change_relaydomain"),
-    ("postfix_relay_domains", "relaydomain", "delete_relaydomain"),
-    ("postfix_relay_domains", "relaydomainalias", "add_relaydomainalias"),
-    ("postfix_relay_domains", "relaydomainalias", "change_relaydomainalias"),
-    ("postfix_relay_domains", "relaydomainalias", "delete_relaydomainalias"),
-    ("postfix_relay_domains", "service", "add_service"),
-    ("postfix_relay_domains", "service", "change_service"),
-    ("postfix_relay_domains", "service", "delete_service")
-]
-
 
 class PostfixRelayDomains(ModoExtension):
 
diff --git a/modoboa/extensions/radicale/general_callbacks.py b/modoboa/extensions/radicale/general_callbacks.py
index 4688f748a..9cfb78938 100644
--- a/modoboa/extensions/radicale/general_callbacks.py
+++ b/modoboa/extensions/radicale/general_callbacks.py
@@ -6,6 +6,26 @@ from django.core.urlresolvers import reverse
 from django.utils.translation import ugettext as _
 from modoboa.lib import events
 
+PERMISSIONS = [
+    ("radicale", "usercalendar", "add_usercalendar"),
+    ("radicale", "usercalendar", "change_usercalendar"),
+    ("radicale", "usercalendar", "delete_usercalendar"),
+    ("radicale", "sharedcalendar", "add_sharedcalendar"),
+    ("radicale", "sharedcalendar", "change_sharedcalendar"),
+    ("radicale", "sharedcalendar", "delete_sharedcalendar")
+]
+
+ROLES_PERMISSIONS = {
+    "DomainAdmins": PERMISSIONS,
+    "Resellers": PERMISSIONS
+}
+
+
+@events.observe("GetExtraRolePermissions")
+def extra_permissions(rolename):
+    """Extra permissions."""
+    return ROLES_PERMISSIONS.get(rolename, [])
+
 
 @events.observe("UserMenuDisplay")
 def top_menu(target, user):
diff --git a/modoboa/extensions/radicale/migrations/0002_load_initial_data.py b/modoboa/extensions/radicale/migrations/0002_load_initial_data.py
deleted file mode 100644
index b21ff3896..000000000
--- a/modoboa/extensions/radicale/migrations/0002_load_initial_data.py
+++ /dev/null
@@ -1,37 +0,0 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
-
-from modoboa.core.extensions import exts_pool
-from modoboa.lib.migration_tools import add_permissions_to_group
-
-
-def load_initial_data(apps, schema_editor):
-    """Load initial data."""
-
-    permissions = [
-        ("radicale", "usercalendar", "add_usercalendar"),
-        ("radicale", "usercalendar", "change_usercalendar"),
-        ("radicale", "usercalendar", "delete_usercalendar"),
-        ("radicale", "sharedcalendar", "add_sharedcalendar"),
-        ("radicale", "sharedcalendar", "change_sharedcalendar"),
-        ("radicale", "sharedcalendar", "delete_sharedcalendar")
-    ]
-
-    add_permissions_to_group(apps, "DomainAdmins", permissions)
-    if not exts_pool.is_extension_installed(
-            "modoboa.extensions.limits"):
-        return
-    add_permissions_to_group(apps, "Resellers", permissions)
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('radicale', '0001_initial'),
-    ]
-
-    operations = [
-        migrations.RunPython(load_initial_data)
-    ]
diff --git a/modoboa/lib/migration_tools.py b/modoboa/lib/migration_tools.py
deleted file mode 100644
index 307acad6f..000000000
--- a/modoboa/lib/migration_tools.py
+++ /dev/null
@@ -1,18 +0,0 @@
-"""Additional functions available for migration scripts."""
-
-
-def add_permissions_to_group(apps, group, permissions):
-    """Add the specified permissions to a django group."""
-    Permission = apps.get_model("auth", "Permission")
-    ContentType = apps.get_model("contenttypes", "ContentType")
-
-    if isinstance(group, basestring):
-        Group = apps.get_model("auth", "Group")
-        group = Group.objects.get(name=group)
-
-    for appname, modelname, permname in permissions:
-        ct = ContentType.objects.get_by_natural_key(
-            appname, modelname)
-        group.permissions.add(
-            Permission.objects.get(content_type=ct, codename=permname)
-        )
diff --git a/modoboa/lib/permissions.py b/modoboa/lib/permissions.py
index 5558bc3e6..661db46fb 100644
--- a/modoboa/lib/permissions.py
+++ b/modoboa/lib/permissions.py
@@ -1,5 +1,6 @@
 # coding: utf-8
 
+from django.contrib.auth.models import Group, Permission
 from django.contrib.contenttypes.models import ContentType
 from django.db import IntegrityError
 from django.utils.translation import ugettext as _
@@ -147,3 +148,18 @@ def get_object_owner(obj):
     except ObjectAccess.DoesNotExist:
         return None
     return entry.user
+
+
+def add_permissions_to_group(group, permissions):
+    """Add the specified permissions to a django group."""
+    if isinstance(group, basestring):
+        group = Group.objects.get(name=group)
+
+    for appname, modelname, permname in permissions:
+        ct = ContentType.objects.get_by_natural_key(appname, modelname)
+        if group.permissions.filter(
+                content_type=ct, codename=permname).exists():
+            continue
+        group.permissions.add(
+            Permission.objects.get(content_type=ct, codename=permname)
+        )