The existing code does not offer support for custom networks in google cloud. In case, custom networks are provided, new agents fail to spawn. Please look into it
I am not aware of any issues with custom networks, however, we often see firewall rules that prevent inbound traffic to the instance at port 2376, or firewall rules that prevent outbound traffic to dockerhub or to the drone server, which prevents the autoscaler from provisioning instances.
In order to help you further debug we need the following information:
- autoscaler configuration
- autoscaler logs with debug and trace enabled
- cloud-init logs from the remote server that failed to spawn
- docker daemon logs from the remote server
- docker logs for the agent from the remote server
Once we have the above information we can recommend next steps.