Tutum use to offer a cute set of monitoring graphs on node instances directly within their web dashboard. The acquisition by Docker saw these options vanish with the release of DockerCloud. That left me searching for a convenient (and inexpensive) way of monitoring Docker Cloud nodes; utilisation, memory-consumption, file-system and so on.
Enter Datadog.
You’ll need to set up a trial account at https://www.datadoghq.com/ to get your API key. The service is free indefinitely for less than 5 nodes.
You can add a utility stack to your Docker Cloud set up that automatically deploys the monitoring agent as a container on every node. Not sure what the original tutum container offers beyond metadata so here is my stackfile for datadog using their agent container directly:
datadog:
image: 'datadog/docker-dd-agent:latest'
deployment_strategy: every_node
environment:
- API_KEY=YOURAPIKEYHERE
- HOSTNAME=$DOCKERCLOUD_NODE_HOSTNAME
privileged: true
restart: on-failure
volumes:
- '/var/run/docker.sock:/var/run/docker.sock'
- '/proc:/host/proc:ro'
- '/sys/fs/cgroup:/host/sys/fs/cgroup:ro'
Note the need to use $DOCKERCLOUD_NODE_HOSTNAME as the hostname. Unfortunately this now gives you an ‘orrible UUID as a node name.