How to Resolve the "NoRegionError: You Must Specify a Region" Error in Panther
This error typically occurs when the Python code used for the detection logic tries to interact with AWS services, such as DynamoDB, without specifying the necessary AWS environment variables.
The NoRegionError usually arises in scenarios where you are:
Running the Panther Analysis Tool in a local environment.
Running the Panther Analysis Tool in automated CI/CD workflows such as GitHub Actions.
This behavior occurs because the detection code is trying to make AWS API calls.
To resolve this, you can:
Update the unit tests of the detection so they only test code paths that do not make API calls.
Alternatively, you can update the unit tests so that any functions/python code making API calls will be mocked, preventing these calls from being made. You can use Panther's mocking features to accomplish this.
Please note, that you will not receive the same behavior when running the same actions in your Panther Console. When your detection rules are running in the Panther backend, they execute on Panther's Lambda functions. These functions have all the necessary environment variables and permissions configured, allowing them to interact with the AWS services seamlessly.