From cd1fa561260649de74fbd72a23d839509af3d9c4 Mon Sep 17 00:00:00 2001
From: Thomas NOEL <tnoel@entrouvert.com>
Date: Fri, 24 Oct 2014 16:36:00 +0200
Subject: [PATCH] add safemigrate_schemas command (#5791)

---
 .../commands/safemigrate_schemas.py           | 97 +++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 entrouvert/djommon/multitenant/management/commands/safemigrate_schemas.py

diff --git a/entrouvert/djommon/multitenant/management/commands/safemigrate_schemas.py b/entrouvert/djommon/multitenant/management/commands/safemigrate_schemas.py
new file mode 100644
index 0000000..0516111
--- /dev/null
+++ b/entrouvert/djommon/multitenant/management/commands/safemigrate_schemas.py
@@ -0,0 +1,97 @@
+# this file derive from django-tenant-schemas
+#   Author: Bernardo Pires Carneiro
+#   Email: carneiro.be@gmail.com
+#   License: MIT license
+#   Home-page: http://github.com/bcarneiro/django-tenant-schemas
+from django.conf import settings
+from django.db import connection
+from south import migration
+from south.migration.base import Migrations
+from entrouvert.djommon.multitenant.middleware import TenantMiddleware
+from entrouvert.djommon.multitenant.management.commands import SyncCommon
+from entrouvert.djommon.management.commands.safemigrate import Command as SafeMigrateCommand
+from entrouvert.djommon.multitenant.management.commands.sync_schemas import Command as MTSyncCommand
+from entrouvert.djommon.multitenant.management.commands.migrate_schemas import Command as MTMigrateCommand
+
+
+class Command(SyncCommon):
+    help = "Safely migrate schemas with South"
+    option_list = MTMigrateCommand.option_list
+
+    def handle(self, *args, **options):
+        super(Command, self).handle(*args, **options)
+
+        MTSyncCommand().execute(*args, **options)
+        connection.set_schema_to_public()
+        if self.sync_public:
+            self.fake_public_apps()
+        if self.sync_tenant:
+            self.fake_tenant_apps(self.domain)
+        connection.set_schema_to_public()
+        MTMigrateCommand().execute(*args, **options)
+
+    def _set_managed_apps(self, included_apps, excluded_apps):
+        """ while sync_schemas works by setting which apps are managed, on south we set which apps should be ignored """
+        ignored_apps = []
+        if excluded_apps:
+            for item in excluded_apps:
+                if item not in included_apps:
+                    ignored_apps.append(item)
+
+        for app in ignored_apps:
+            app_label = app.split('.')[-1]
+            settings.SOUTH_MIGRATION_MODULES[app_label] = 'ignore'
+
+    def _save_south_settings(self):
+        self._old_south_modules = None
+        if hasattr(settings, "SOUTH_MIGRATION_MODULES") and settings.SOUTH_MIGRATION_MODULES is not None:
+            self._old_south_modules = settings.SOUTH_MIGRATION_MODULES.copy()
+        else:
+            settings.SOUTH_MIGRATION_MODULES = dict()
+
+    def _restore_south_settings(self):
+        settings.SOUTH_MIGRATION_MODULES = self._old_south_modules
+
+    def _clear_south_cache(self):
+        for mig in list(migration.all_migrations()):
+            delattr(mig._application, "migrations")
+        Migrations._clear_cache()
+
+    def _fake_schema(self, tenant):
+        connection.set_tenant(tenant, include_public=False)
+        SafeMigrateCommand().fake_if_needed()
+
+    def fake_tenant_apps(self, schema_name=None):
+        self._save_south_settings()
+
+        apps = self.tenant_apps or self.installed_apps
+        self._set_managed_apps(included_apps=apps, excluded_apps=self.shared_apps)
+
+        if schema_name:
+            self._notice("=== Running fake_if_needed for schema: %s" % schema_name)
+            connection.set_schema_to_public()
+            tenant = TenantMiddleware.get_tenant_by_hostname(schema_name)
+            self._fake_schema(tenant)
+        else:
+            all_tenants = TenantMiddleware.get_tenants()
+            if not all_tenants:
+                self._notice("No tenants found")
+
+            for tenant in all_tenants:
+                Migrations._dependencies_done = False  # very important, the dependencies need to be purged from cache
+                self._notice("=== Running fake_if_needed for schema %s" % tenant.schema_name)
+                self._fake_schema(tenant)
+
+        self._restore_south_settings()
+
+    def fake_public_apps(self):
+        self._save_south_settings()
+
+        apps = self.shared_apps or self.installed_apps
+        self._set_managed_apps(included_apps=apps, excluded_apps=self.tenant_apps)
+
+        self._notice("=== Running fake_if_needed for schema public")
+        SafeMigrateCommand().fake_if_needed()
+
+        self._clear_south_cache()
+        self._restore_south_settings()