script to migrate south migrations to a custom auth user model (has already been…

script to migrate south migrations to a custom auth user model (has already been run on wiki.migrations)

custom_user_auth_south_refactor.py

+# -*- coding: utf-8 -*-
+"""Refactor South migrations to use settings.AUTH_USER_MODEL.
+Inserts a backwards-compatible code-snippet in all
+your schema migration files and uses a possibly customized user
+model as introduced in Django 1.5.
+
+Please note that this has nothing to do with changing
+settings.AUTH_USER_MODEL to a new model. If you do this, stuff
+will very likely break in reusable apps that have their own
+migration trees.
+
+Attributions:
+github "benjaoming" this script
+
+github "rockymeza" for this commit which held the ingredients:
+https://github.com/fusionbox/mezzanine/commit/a9ea14719ad70ef2c92b26162eb3ae90283dbea2
+
+Stackexchange Q&A:
+http://stackoverflow.com/questions/15472704/trouble-migrating-reusable-django-app-models-to-use-a-custom-user-model
+
+Usage:
+  custom_user_auth_south_refactor.py <migration-dir>
+  custom_user_auth_south_refactor.py (-h | --help)
+  custom_user_auth_south_refactor.py --version
+
+Options:
+  -h --help     Show this screen.
+  --version     Show version.
+
+"""
+from docopt import docopt
+import os
+import re
+
+RE_CLASS_NAME = re.compile(r'^()^(class\s+Migration\s*\(\s*(SchemaMigration|DataMigration)\s*\)\s*:)', 
+    re.MULTILINE)
+
+INSERT_AT_TOP_OF_MIGRATION = """try:
+    from django.contrib.auth import get_user_model
+except ImportError: # django < 1.5
+    from django.contrib.auth.models import User
+else:
+    User = get_user_model()
+
+user_orm_label = '%s.%s' % (User._meta.app_label, User._meta.object_name)
+user_model_label = '%s.%s' % (User._meta.app_label, User._meta.module_name) 
+
+
+"""
+RE_FK_LABEL = re.compile(r"to\=orm\[\'auth\.User\'\]")
+RE_FK_LABEL_TO = "to=orm[user_orm_label]"
+
+RE_FK_BACKWARDS = re.compile(r"'to':\s*\"orm\['auth\.User'\]\"")
+RE_FK_BACKWARDS_TO = "'to': \"orm['%s']\" % user_orm_label"
+
+RE_AUTH_MODEL = re.compile(r"'auth\.user'\:\s*\{")
+RE_AUTH_MODEL_TO = r"user_model_label: {"
+
+RE_META_STRING = re.compile(r"'Meta':\s*\{\s*'object_name'\s*:\s*'User'\s*\}")
+RE_META_TO = "'Meta': {'object_name': User.__name__, 'db_table': \"'%s'\" % User._meta.db_table}"
+
+RE_TEST_OK = re.compile(r"'auth.User'", re.IGNORECASE)
+
+RE_MIGRATION_FNAME = re.compile(r"^(\d{4}).+py$")
+
+if __name__ == '__main__':
+    arguments = docopt(__doc__, version='1.0')
+    migration_dir = arguments['<migration-dir>']
+    for fname in os.listdir(migration_dir):
+        if not RE_MIGRATION_FNAME.search(fname):
+            continue
+        full_path = os.path.join(migration_dir, fname)
+        f = open(full_path, 'r')
+        contents = f.read()
+        f.close()
+        if RE_FK_LABEL.search(contents) or RE_META_STRING.search(contents) or RE_AUTH_MODEL.search(contents) or RE_FK_LABEL.search(contents):
+            print "Refactoring {0}".format(fname)
+            f = open(full_path, 'w')
+            contents = RE_CLASS_NAME.sub(INSERT_AT_TOP_OF_MIGRATION + r"\2", 
+                contents)
+            contents = RE_AUTH_MODEL.sub(RE_AUTH_MODEL_TO, contents)
+            contents = RE_META_STRING.sub(RE_META_TO, contents)
+            contents = RE_FK_BACKWARDS.sub(RE_FK_BACKWARDS_TO, contents)
+            contents = RE_FK_LABEL.sub(RE_FK_LABEL_TO, contents)
+            f.write(contents)
+            f.close()
+        else:
+            print "Skipping {0}".format(fname)            
+        if RE_TEST_OK.search(contents):
+            print "    WARNING! Still found occurrences of auth.User. Fix manually!"