Hung or stuck instances not torn down

[MaxDiOrio]

When a build fails and the EC2 instance doesn't run the shutdown script it seems that the EC2 instance is never cleaned up. The one below was a timeout waiting for the self-hosted runner to register.

Ec2 spot instance strategy is set to none
Starting instance with none strategy
AWS EC2 instance i-01967a62320981c42 is up and running
Waiting 30s before polling for runner
Polling for runner every 10s
Waiting...
Waiting...
...
Waiting...
Error: The operation was canceled.

And the instance remained up.

[mahdi-torabi]

 `echo "shutdown -P +1" > $CURRENT_PATH/shutdown_script.sh`,
      "chmod +x $CURRENT_PATH/shutdown_script.sh",
      `echo "./config.sh remove --token ${runnerRegistrationToken.token} || true" > $CURRENT_PATH/shutdown_now_script.sh`,
      `echo "shutdown -h now" > $CURRENT_PATH/shutdown_now_script.sh`,
      "chmod +x $CURRENT_PATH/shutdown_now_script.sh",
      "export ACTIONS_RUNNER_HOOK_JOB_COMPLETED=$CURRENT_PATH/shutdown_script.sh",

• The code above creates a shutdown script and then uses ACTIONS_RUNNER_HOOK_JOB_COMPLETED to make sure it is executed once a job finishes.
• We also have github_job_start_ttl_seconds which defines how long an instance is allowed to stay idle before a job is executed
• Finally we have the instance TTL which would execute if the two options above both fail for any reason.

I just tested with a job which had an error intentionally introduced to make it fail. Exactly 1 minute after failure the instance was terminated.

Do you have an example of a workflow which could trigger a different type of failure ?