Adding a configuration

This site explains how to create a new configuration, both for the generic part and for the application.

The following illustration shows the structure of the project:

Application
 ├── src
 │   ├── __init__.py
 │   ├── db.py
 │   ├── configuration.py
 │   └── tetue_generic
 │       ├── __init__.py
 │       └── watcher.py
 ├── default.env
 └── main.py

Generic

Create a new module in the generic folder, e.g. gentester.py. If a configuration is required for the new generic parts, the following must be created.

1. Create a configuration class in gentester.py, customize delimiter and change the default value test_var

import environ

@environ.config(prefix="TEST_CONF")
class GenTestConfiguration:
    """
    Configuration settings for test example.
    """

    request_timeout = environ.var(
        "test_var", help="This variable is just for testing purposes"
    )

2. Import the new configuration class in src/configuration.py

from .tetue_generic.gentester import GenTestConfiguration

3. Add the new configuration variables to Configuration in src/configuration.py

@environ.config(prefix="TT")
class Configuration:
    """
    Configuration class for the entire application, grouping all sub-configurations.
    """
    gen_req = environ.group(GenReqConfiguration)
    watcher = environ.group(WatcherConfiguration)
    gentester = environ.group(GenTestConfiguration)

4. Add new configuration variables to .env with nested delimiter .. code-block:: rst

TT_TEST_CONF_TEST_VAR=example_value

Application

For the application, the configuration is created in the same way as for the generic part. For example, if a database configuration is required (for src/db.py), proceed the same ways as above.

Primary

If you need settings that are once again superordinate in the project, i.e. are not directly assigned to a module (user and name), these are specified and verified directly in the configuration class.

@environ.config(prefix="TT")
class Configuration:
    """
    Configuration class for the entire application, grouping all sub-configurations.
    """
    test_value = environ.var("value", help="This is a value.")
    gen_req = environ.group(GenReqConfiguration)
    watcher = environ.group(WatcherConfiguration)
    gentester = environ.group(GenTestConfiguration)

The new variable is then added to .env as follows:

TT_TEST_VALUE=example_value

Note

It is not necessary to write all the letters in uppercase. The library automatically converts it. However, it is recommended to use uppercase letters for better readability.

Validation

It is possible to validate configuration variables. The library environ supports this natively. For further information, refer to official documentation of environ.