serve per-instance static files at custom-static/

incorporealcms/__init__.py

@@ -40,8 +40,9 @@ def create_app(instance_path=None, test_config=None):
         logger.info("RESPONSE: %s %s: %s", request.method, request.path, response.status)
         return response
 
-    from . import error_pages, pages
+    from . import error_pages, pages, static
     app.register_blueprint(pages.bp)
+    app.register_blueprint(static.bp)
     app.register_error_handler(400, error_pages.bad_request)
     app.register_error_handler(404, error_pages.page_not_found)
     app.register_error_handler(500, error_pages.internal_server_error)

incorporealcms/static.py

@@ -0,0 +1,14 @@
+"""Serve static files from the instance directory."""
+import os
+
+from flask import Blueprint
+from flask import current_app as app
+from flask import send_from_directory
+
+bp = Blueprint('static', __name__, url_prefix='/custom-static')
+
+
+@bp.route('/<path:name>')
+def serve_instance_static_file(name):
+    """Serve a static file from the instance directory, used for customization."""
+    return send_from_directory(os.path.join(app.instance_path, 'custom-static'), name)