In this article, we will explore some of the common causes for "empty" workers, with no associated Docker activity, and how to address them.
Common Causes
You may sometimes encounter a warning message stating "this worker was requested by the Testcontainers Cloud agent but seemingly didn’t run any containers." This warning indicates that the worker did not perform any expected work. This can happen when:
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Running Docker commands directly in the terminal. Typically, Testcontainers Cloud users rely on the Testcontainers open-source libraries to control the lifecycle of their containers. Executing raw Docker commands directly against the TCC Docker context is unsupported. For example, if you run Docker commands (e.g. `docker ps`) directly on your machine while the Testcontainers Cloud agent is active but no worker is currently connected, you might accidentally start a new worker.
- Starting the Testcontainers Cloud agent in CI pipelines without Testcontainers-based tests. When starting the Testcontainers Cloud agent in your CI/CD pipelines, it is important to ensure that your pipeline jobs actually include Testcontainers-based tests. If you start the agent in pipelines that don't run any Testcontainers-based tests, the worker will start and wait, without performing any useful activity.
Troubleshooting Steps
If you encounter the "no activity detected" warning, consider the following troubleshooting steps:
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Review CI pipeline configuration: inspect your CI/CD pipeline configuration and verify that the appropriate stages are set up to execute Testcontainers-based tests. Ensure that the pipeline triggers the execution of these tests.
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Avoid Docker command interference: ensure that you are not running any Docker commands directly on your desktop machine while the Testcontainers Cloud agent is active. These external commands can interfere with the agent's ability to control and manage containers.
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Validate Testcontainers integration: double-check the integration of Testcontainers within your test codebase. Ensure that the necessary dependencies and configurations are in place. Confirm that the tests correctly invoke Testcontainers APIs to create and manage containers.
Conclusion
The "No activity detected" warning in Testcontainers Cloud indicates that a worker did not run any containers as expected. By avoiding external Docker commands on the desktop and ensuring that CI pipelines execute Testcontainers-based tests, you can minimize "empty" workers and leverage the full capabilities of Testcontainers Cloud.
If the issue persists, consult the Testcontainers Cloud documentation or contact us to help further troubleshoot and resolve the problem.