Runner nodes are terminated immediately after startup

[philvarner]

Just reporting this here in case anyone else encounters it. Last week (July 10, 2025), our runners suddenly stopped working. New EC2 instances are created, but are immediately terminated by the Monitor after startup. We were unable to determine why this is happening, and instead of continuing to debug, have decided to move away from using this project to another solution.

[philvarner]

This comment on the terraform-aws-gitlab-runner may indicate the problem -- cattle-ops/terraform-aws-gitlab-runner#1291 (comment)

we discovered that the ami version we were using was EOL and updates were no longer supported by Ubuntu. We changed the runner_worker_docker_machine_ami_filter to use a supported version 24.04 from 20.04, which resolved our issue.