Let us create the first alert. We'll update our go-demo_main service by adding a few labels:
docker service update \ --label-add com.df.alertName=mem \ --label-add com.df.alertIf='container_memory_usage_\bytes{container_label_com_docker_swarm_service_name=\"go-demo_main"} > 20000000' \ go-demo_main
The label com.df.alertName is the name of the alert. It will be prefixed with the name of the service stripped from underscores and dashes (godemomem). That way, a unique alert ...