Fixed bug that caused apache2+wsgi deployment to break (#1030)

* Create a `flask_migrate.stamp()` wrapper in `CTFd.utils.migrations` that always references the migrations folder regardless of how CTFd is run or deployed.
* Closes #257 properly

CTFd/utils/exports/__init__.py

@@ -1,11 +1,11 @@
 from CTFd.utils import get_app_config, set_config
-from CTFd.utils.migrations import get_current_revision, create_database, drop_database
+from CTFd.utils.migrations import get_current_revision, create_database, drop_database, stamp_latest_revision
 from CTFd.utils.uploads import get_uploader
 from CTFd.models import db
 from CTFd.cache import cache
 from datafreeze.format import SERIALIZERS
 from flask import current_app as app
-from flask_migrate import upgrade, stamp
+from flask_migrate import upgrade
 from datafreeze.format.fjson import JSONSerializer, JSONEncoder
 from sqlalchemy.exc import OperationalError, ProgrammingError
 from alembic.util import CommandError
@@ -278,7 +278,7 @@ def import_ctf(backup, erase=True):
         upgrade(revision="head")
     except (CommandError, RuntimeError, SystemExit):
         app.db.create_all()
-        stamp()
+        stamp_latest_revision()
 
     # Invalidate all cached data
     cache.clear()

CTFd/utils/migrations/__init__.py

@@ -1,5 +1,5 @@
 from flask import current_app as app
-from flask_migrate import Migrate
+from flask_migrate import Migrate, stamp
 from alembic.migration import MigrationContext
 from sqlalchemy import create_engine
 from sqlalchemy.engine.url import make_url
@@ -8,6 +8,7 @@ from sqlalchemy_utils import (
     create_database as create_database_util,
     drop_database as drop_database_util,
 )
+import os
 
 migrations = Migrate()
 
@@ -42,3 +43,9 @@ def get_current_revision():
     context = MigrationContext.configure(conn)
     current_rev = context.get_current_revision()
     return current_rev
+
+
+def stamp_latest_revision():
+    # Get proper migrations directory regardless of cwd
+    directory = os.path.join(os.path.dirname(app.root_path), 'migrations')
+    stamp(directory=directory)