Configuration

Configuration via Environment Variables

The application can be configured through several environment variables. Below is a description of some key variables and their usage:

1. PROMPTLY_MAINTENANCE_MODE

   This variable is used to toggle maintenance mode for the application. When maintenance mode is active, the application will respond with a “503 Service Unavailable” status for every request. To activate maintenance mode, set the variable to a truthy value (e.g., “True” or “1”). The variable can be unset or set to a falsy value (e.g., “False” or “0”) to deactivate maintenance mode.

   Example usage:

   $ export PROMPTLY_MAINTENANCE_MODE=True
   $ flask --app runner:app run
   

2. PROMPTLY_SETTINGS

   This variable points to a configuration file that can hold additional configuration settings for the application. The configuration file should be a Python file, and only variables defined in uppercase will be read and applied.

   Example usage:

   $ export PROMPTLY_SETTINGS="/path/to/settings.cfg"
   $ flask --app runner:app run
   

3. PROMPTLY_CONFIG

   This variable defines the startup mode of the application. Valid values include “development”, “testing”, “production”, and “default” (which is an alias for “development”). This variable influences how the application is initialized, but it is separate from the --debug flag used with the Flask script.

   Example usage:

   $ export PROMPTLY_CONFIG=production
   $ flask --app runner:app run
   

4. PROMPTLY_THREAD_TIMEOUT

   This variable defines the maximum amount of time, in seconds, that the threaded_execute() function will wait for the completion of the function it is executing in a separate thread. If the function does not complete within this time, a TimeoutError will be thrown, logged, and the function will be invoked again with the same arguments.

   The default value is 60 seconds, but you can adjust this according to the specific requirements of your environment by setting a different value for PROMPTLY_THREAD_TIMEOUT in this configuration file. This timeout setting helps in ensuring that the function does not hang indefinitely and consumes resources, while providing a mechanism to handle scenarios where the function takes longer than expected to execute.

   It’s essential to set a reasonable timeout value to balance between giving the function enough time to complete its execution and preventing resource exhaustion in case of functions that might hang or take an excessive amount of time to finish.

   Example usage:

   $ export PROMPTLY_THREAD_TIMEOUT=120  # Sets the timeout to 120 seconds.
   $ flask --app runner:app run
   

These environment variables provide a flexible way to configure the application’s behavior without changing the code. They can be set in the shell before starting the server or provided through other means depending on the deployment environment.