Configuration

The test system supports multiple ways of configuration and comes with default values as a solid starting point for a functioning system. Environment variables and a JSON config file are available to customize the test system.

Note

JSON config has the highest priority, followed by environment variables. A property set in the config file overrides an environment variable if present and the default values.

Noteworthy properties

Some of the most essential parameters for operational use are the following:

exercise_nr The exercise number up to which testing is done.
group_ids A list of group ids participating in the course.
term The current term.
tu_connections Defines which connections must exist between a MSP430 and a PicoScope to form a Test Unit.

For a comprehensive list of available settings, look at the Config class.

Environment Variables

Configuration via environment variables can be used to customize the test system on startup. Environment variables are instrumental when the system runs as a docker image or as part of docker-compose. The naming convention for environment variables is UPPER_CASE with underscores and prefixed with ATTEST_ .

Note

To set a list parameter with an environment variable, concatenate the values with ;.

To change the parameter run_hello_testsystem, which starts the hello world equivalent for the test system, you would set the following environment variable:

ATTEST_RUN_HELLO_TESTSYSTEM=True

Config File

The config file enables dynamic configuration changes without restarting the test system. Keep in mind that some settings won’t take effect when set for a running instance, for example, the database type is only used during startup. But in general, assigning a value in the JSON config will take effect the next time the test system requests the parameter. The file has a flat hierarchy with coherent camelCase or PascalCase property names.

The JSON config to change the parameter run_hello_testsystem would look like one of the following examples:

{
    "runHelloTestsystem": true
}

{
    "RunHelloTestsystem": true
}

Notice that changing this setting after startup will not affect the system because run_hello_testsystem is only used during startup.

Note

The default config file path is ./config.json relative to the test system root directory. To change the path take a look at the conf_file property.

Default Configuration

The default configuration serves as a starting point to spin up a functioning instance of the test system. These parameters are set in Config and should usually not be changed. Changes in default parameters would be subject to source code and implementation changes. The default values should guarantee that the current implementation runs without further configuration.

How to use and extend Config

If you need an additional configuration parameter for further extension of the test system, add a member to the Config class with a short description of its functionality as a comment. To access the configuration in code use the get_config() function as followed:

from testsystem.config import get_config

config = get_config()