问题
As title says, I have small web app, without using database and models.
I'd like interface to change some of Flask own config parameters, and thought that flask-admin may bring me there quickly. Is this easily possible?
回答1:
You can't generally change configuration after starting the application without restarting the server.
- The application (at least in production) will be served with multiple processes, possibly even on multiple servers. Changes to the configuration will only effect the process that handled the request, until the other processes are reaped and re-start. Even then, they may fork from a time after the configuration was read.
- Extensions are not consistent about how they read configuration. Some read the configuration from
current_appevery request. Some only read it duringinit_appand store their own copy, so changing the configuration wouldn't change their copy. - Even if the configuration is read each time, some configuration just can't be changed, or requires other steps as well. For example, if you change databases, you should probably make sure you also close all connections to the old database, which the config knows nothing about. Another example, you could change debug mode but it won't do anything, because most of the logging is set up ahead of time.
The web app might not be the only thing relying on the configuration, so even if you could restart it automatically when configuration changed, you'd also need to restart dependent services such as Celery. And those services also might be on completely different machines or as different users.
Configuration is typically stored in Python files, so you'd need to create a serializer that can dump valid Python code, or write a config loader for a different format.
Flask-Admin might be able to be used to create a user interface for editing the configuration, but it wouldn't otherwise help with any of these issues.
It's not really worth it to try and change Flask.config after starting the application. It's just not designed for that. Design a config system specifically for the config you need if that's something you need, but don't expect to be able to generally change Flask.config.
来源：https://stackoverflow.com/questions/39318487/use-flask-admin-to-set-config-parameters