Option to Configure Umask in Config File

Why it matters

This feature was added to allow users to explicitly set the umask value for the ClickHouse process via configuration. It solves the problem of managing default file permission masks more conveniently and consistently without modifying startup scripts or environment settings. This helps ensure correct file permission settings for files created by ClickHouse, improving security and operability.

How to use it

To use this feature, add the option to the ClickHouse server configuration file under the main section. Specify the desired umask value as an octal string, for example:

<umask>022</umask>

Then restart the ClickHouse server for the change to take effect.