Metric of "lost communication with the server" error

[int128]

Problems to solve

Eventually a self-hosted runner is killed by OOM or some issue. It is called "lost communication with the server" error.

• Ephemeral (single use) runner registrations actions/runner#510
• Dealing with jobs failing with "lost communication with the server" errors actions/actions-runner-controller#466

When the error occurred, GitHub Actions adds an annotation with the following message:

The self-hosted runner: POD_NAME lost communication with the server. Verify the machine is running and has a healthy network connection. Anything in your workflow that terminates the runner process, starves it for CPU/Memory, or blocks its network access can cause this error.

Currently, we send the annotation message to Slack by this action:
https://github.com/int128/workflow-run-summary-action/blob/216f94dd10d099652cfb393e598c2a8f604c3bd0/src/run.ts#L60

How to solve

It would be nice to monitor the count of "lost communication with the server" errors for fact-based decision.