Platforms and Runner Images Affected

Oct 13, 2025 by wbrum.org 40 views

Description

As a maintainer of the small project TrafficJam, a firewall for Docker, I have been experiencing intermittent false CI failures on Ubuntu 24.04 related to Docker startup. The CI uses docker-in-docker containers to set up consistent test environments, relying on various Docker tasks and daemon startups. Unfortunately, the timeouts set throughout the CI scripts are being triggered randomly, indicating that the daemons are not starting up at all.

Understanding the Issue

The issue is not related to the daemons being slow to start, but rather, they are not starting up at all. This is evident from the logs, which show that the daemons are not responding within the set timeouts. The same code that runs successfully on my own Ubuntu 24.04 machine is failing on the CI, indicating that the issue is not related to the code itself.

Example Use Cases

To illustrate the issue, I have provided several examples of failed CI runs:

A PR that only changes the README file, but the CI fails: https://github.com/kaysond/trafficjam/actions/runs/13528945516/job/38684067298?pr=25
The same code that runs successfully on the PR is failing on the develop branch: https://github.com/kaysond/trafficjam/actions/runs/13488673721/job/37683334887

Platforms and Runner Images Affected

The issue is affecting the following platforms and runner images:

GitHub Actions - Standard Runners: The issue is affecting the standard runners on GitHub Actions.
Ubuntu 24.04: The issue is specifically related to the Ubuntu 24.04 runner image.
Other platforms and runner images: The issue is not affecting other platforms and runner images, such as Azure DevOps, macOS, and Windows Server.

Image Version and Build Link

The image version and build link are as follows:

Version: 20250209.1.0
Build link: https://github.com/kaysond/trafficjam/actions/runs/13488673721/job/37683334887

Is it a Regression?

The issue is unknown whether it is a regression or not.

Expected Behavior

The expected behavior is that the run should succeed.

Actual Behavior

The actual behavior is that the run fails.

Repro Steps

To reproduce the issue, please see the link above.

Possible Causes

There are several possible causes for this issue:

Runner overload: It is possible that the runners are heavily loaded, causing the daemons to not start up at all.
Runner configuration: The runner configuration may be causing the issue, such as incorrect settings or outdated versions.
Docker version: The Docker version may be causing the issue, such as compatibility issues or outdated versions.

Solutions

To solve this issue, the following solutions can be tried:

Increase runner resources: Increasing the runner resources, such as CPU and memory, may help to resolve the issue.
Update runner configuration: Updating the runner configuration to the latest version may help to resolve the issue.
Update Docker version: Updating the Docker version to the latest version may help to resolve the issue.

Conclusion

In conclusion, the intermittent false CI failures on Ubuntu 24.04 related to Docker startup are a complex issue that requires further investigation. The possible causes and solutions outlined above can be used as a starting point for troubleshooting and resolving the issue.

Future Work

Future work on this issue may include:

Investigating runner overload: Investigating whether the runners are heavily loaded and causing the issue.
Updating runner configuration: Updating the runner configuration to the latest version.
Updating Docker version: Updating the Docker version to the latest version.

References

TrafficJam
GitHub Actions
Docker
Intermittent False CI Failures on Ubuntu 24.04 Related to Docker Startup: Q&A ================================================================================

Q: What is the issue with the CI failures on Ubuntu 24.04?

A: The issue is that the CI is failing intermittently on Ubuntu 24.04 due to Docker startup failures. The daemons are not starting up at all, causing the timeouts to be triggered.

Q: What are the possible causes of this issue?

A: There are several possible causes for this issue, including:

Runner overload: The runners may be heavily loaded, causing the daemons to not start up at all.
Runner configuration: The runner configuration may be causing the issue, such as incorrect settings or outdated versions.
Docker version: The Docker version may be causing the issue, such as compatibility issues or outdated versions.

Q: How can I troubleshoot this issue?

A: To troubleshoot this issue, you can try the following:

Increase runner resources: Increase the runner resources, such as CPU and memory, to see if it resolves the issue.
Update runner configuration: Update the runner configuration to the latest version to see if it resolves the issue.
Update Docker version: Update the Docker version to the latest version to see if it resolves the issue.

Q: What are the expected behavior and actual behavior of the CI?

A: The expected behavior of the CI is that it should run successfully. The actual behavior is that it fails intermittently due to Docker startup failures.

Q: What are the repro steps for this issue?

A: To reproduce the issue, please see the link above.

Q: Is this issue related to the code or the environment?

A: This issue is not related to the code itself, but rather to the environment and the Docker version.

Q: Can I reproduce this issue on my local machine?

A: It is unlikely that you can reproduce this issue on your local machine, as the issue is specific to the CI environment and the Docker version.

Q: What are the possible solutions to this issue?

A: The possible solutions to this issue include:

Increasing runner resources: Increasing the runner resources, such as CPU and memory, to see if it resolves the issue.
Updating runner configuration: Updating the runner configuration to the latest version to see if it resolves the issue.
Updating Docker version: Updating the Docker version to the latest version to see if it resolves the issue.

Q: Can I get help with troubleshooting this issue?

A: Yes, you can get help with troubleshooting this issue by reaching out to the GitHub Actions support team or by posting a question on the GitHub Actions community forum.

Q: What are the next steps to resolve this issue?

A: The next steps to resolve this issue are to:

Investigate runner overload: Investigate whether the runners are heavily loaded and causing the issue.
Update runner configuration: Update the runner configuration to the latest version.
Update Docker version: Update the Docker version to the latest version.

Q: Can I get more information about this issue?

A: Yes, you can get more information about this issue by checking the GitHub Actions documentation and the GitHub Actions community forum.

Q: Is this issue specific to Ubuntu 24.04 or can it affect other platforms?

A: This issue is specific to Ubuntu 24.04, but it may affect other platforms if they are using the same Docker version and runner configuration.

Q: Can I get help with implementing the solutions to this issue?

A: Yes, you can get help with implementing the solutions to this issue by reaching out to the GitHub Actions support team or by posting a question on the GitHub Actions community forum.