How to maintain Audit Logs

Question

I am storing user data in MongoDB and want to maintain activity logs for each user. eg:

1. Who logged in and when?
2. Which user perform certain and when they did

Also, Admin can query over these logs to search

I have certain approach where people suggested that these logs should be stored on persistent disk(log files) and then writing a script to update database from these log files.

I want to know what is a good practice to maintain audit logs. Also, using MongoDB to store all these events will fine?