Lifecycle Hooks

If you need to have some code that runs BEFORE the Q2 Webserver starts up or AFTER it stops to do some necessary setup/teardown for example then there are a convenient set of lifecycle hooks that you can utilize. These hooks will run with the q2 run entrypoint.

To get started, just run the command q2 create_lifecycle_scripts which will create the necessary files in a lifecycle directory at the root of your project.

Startup

This hook lives in the lifecycle/startup.py file and has one required function called handle(). This function takes one argument, and it is of the type StartupData. You can define whatever other functions or import any code in this file that you need. This hook is perfect for doing some extra setup that you may need before the webserver starts up. One simple example is if you are using the dotenv library to define some environment variables in a .env file.

Shutdown

This hook lives in the lifecycle/shutdown.py file and has one required function called handle(). This function takes one argument, and it is of the type ShutdownData. This hook behaves very similarly to startup except it runs AFTER the webserver has stopped. If you need anything to be cleaned up at this point then you can do that here.