Airflow CI Test Failure: InvalidToken In Test_connection.py

Nov 8, 2025 by Admin 60 views

Hey everyone! We've got a critical issue to discuss: a CI test failure popping up in the test_connection.py file within the Apache Airflow project. Specifically, it's throwing a cryptography.fernet.InvalidToken error. This needs our immediate attention to ensure the stability and reliability of Airflow.

The Problem: cryptography.fernet.InvalidToken

Let's dive deeper into the error. The cryptography.fernet.InvalidToken error generally indicates that a token used for encryption or decryption is either invalid, expired, or has been tampered with. In the context of Airflow, this likely points to an issue with how connection details are being encrypted and decrypted, especially when dealing with sensitive information like passwords and API keys.

The error is manifesting in the following tests:

FAILED airflow-core/tests/unit/models/test_connection.py::TestConnection::test_get_uri[***host:100/schema?param1=val1&param2=val2] - cryptography.fernet.InvalidToken
FAILED airflow-core/tests/unit/models/test_connection.py::TestConnection::test_get_uri[connection1-type://protocol://host:100/schema?param1=val1&param2=val2] - cryptography.fernet.InvalidToken
FAILED airflow-core/tests/unit/models/test_connection.py::TestConnection::test_get_uri[connection2-type://***host:100/schema?param1=val1&param2=val2] - cryptography.fernet.InvalidToken

These tests are part of the TestConnection class in test_connection.py, and they specifically focus on the test_get_uri method, which is responsible for constructing the URI (Uniform Resource Identifier) for a connection. The failure suggests that the process of retrieving or constructing the URI is encountering issues with token validation.

This error is observed in the CI (Continuous Integration) environment, as seen in the provided links:

These links point to specific jobs within GitHub Actions, indicating that the error is reproducible in the CI pipeline.

Why This Matters

This isn't just a minor blip, guys. A failure in connection URI generation can have serious implications:

Broken DAGs: If Airflow can't properly connect to external systems (databases, APIs, etc.), your DAGs will fail.
Security Risks: Issues with token validation can potentially expose sensitive connection information.
Deployment Blockers: CI failures prevent merging code and releasing new versions of Airflow.

In short, we need to get this fixed ASAP to keep Airflow running smoothly and securely.

Potential Causes

So, what could be causing this InvalidToken error? Here are some likely culprits:

Fernet Key Issues: The Fernet key is crucial for encrypting and decrypting connection details. If the key is incorrect, has been rotated improperly, or is not being accessed correctly in the test environment, it can lead to this error. This is the most common suspect in InvalidToken errors.
Encryption/Decryption Mismatch: There might be a mismatch between the encryption and decryption processes. For example, if something is encrypted with one Fernet key and attempts to decrypt it with another, the token will be invalid.
Token Expiration: Fernet tokens can have an expiration time. If a token is being used after it has expired, this error will occur. While less likely in this specific scenario, it's still worth considering.
Data Corruption: In rare cases, the encrypted data itself might be corrupted, leading to decryption failures.
Environment Configuration: Differences in environment configurations between the local development environment and the CI environment can sometimes cause unexpected behavior. This could include missing environment variables or incorrect settings.
Code Changes: Recent code changes related to connection handling, encryption, or Fernet key management are potential sources of the issue. It's crucial to review recent commits to identify any possible regressions.

Steps to Reproduce

To effectively troubleshoot, we need to be able to reproduce the error consistently. The reporter has already pointed out the easiest way: run the CI tests. This is excellent because it means we can leverage the existing CI environment to investigate.

However, to make the process even more efficient, consider these additional steps:

Isolate the Test: Try running the specific tests that are failing (test_get_uri within TestConnection) locally. This will help narrow down the scope of the problem.
Debug Locally: Set up a local development environment that closely mirrors the CI environment. This includes using the same Python version, Airflow version, and environment variables. Then, run the tests in debug mode to inspect the values and execution flow.
Check Fernet Key: Verify that the Fernet key being used in the test environment is correct and accessible. You might need to print the key in the test to confirm its value.

Proposed Solutions and Next Steps

Alright, guys, let's talk solutions. Here's a breakdown of potential fixes and how we should proceed:

Investigate Fernet Key Setup:
- Verify Key Generation: Ensure the Fernet key is being generated correctly and consistently across environments. This often involves checking how the secrets.token_urlsafe function is used or if there's a custom key generation process.
- Check Key Storage: Confirm that the key is stored securely and is being retrieved correctly in the test environment. Common storage methods include environment variables, configuration files, or dedicated secrets management systems.
- Key Rotation: If key rotation is in place, verify that the rotation process is functioning as expected and that old keys are being handled correctly. Incorrect key rotation can lead to InvalidToken errors when decrypting data encrypted with an older key.
Review Encryption/Decryption Logic:
- Code Inspection: Carefully review the code responsible for encrypting and decrypting connection details. Pay close attention to how the Fernet key is being used and if there are any potential mismatches.
- Test Cases: Add more test cases to cover different scenarios, including edge cases and error conditions. This will help ensure the encryption and decryption logic is robust.
Examine Environment Configuration:
- Environment Variables: Double-check that all required environment variables are set correctly in the CI environment. Missing or incorrect environment variables can lead to unexpected behavior.
- Configuration Files: Verify that any configuration files used by Airflow are correctly configured in the test environment. This includes settings related to database connections, security, and other dependencies.
Analyze Recent Code Changes:
- Git History: Use git blame and git log to identify recent changes related to connection handling, encryption, or Fernet key management. This will help pinpoint potential regressions introduced by recent commits.
- Code Review: Conduct a thorough code review of the relevant changes to identify any potential issues.
Implement Logging and Debugging:
- Detailed Logs: Add more detailed logging to the encryption and decryption processes. This will provide valuable insights into the values being used and the execution flow.
- Debug Statements: Use debug statements to inspect the Fernet key, the encrypted data, and the decrypted data. This can help identify the point at which the InvalidToken error occurs.

Immediate Next Steps:

Reproduce Locally: Attempt to reproduce the error locally using the steps outlined above.
Inspect Fernet Key: Verify the Fernet key being used in the test environment.
Review Recent Changes: Analyze recent code changes related to connection handling and encryption.

I'm on it! (and you can be too!)

The reporter has bravely volunteered to submit a PR, which is fantastic! This proactive approach is exactly what we need to resolve this issue quickly. If you're keen to help, here's how you can contribute:

Review the PR: Once the PR is submitted, give it a thorough review. Pay close attention to the changes made and how they address the root cause of the error.
Test the Fix: If possible, test the fix locally to ensure it resolves the issue and doesn't introduce any new problems.
Share Your Insights: If you have any insights or suggestions, don't hesitate to share them in the discussion.

Let's work together to squash this bug and keep Airflow flying high! We will update this thread as we make progress.