Docker Swarm cluster missing nodes

While creating a Docker Swarm cluster; only one node would ever join. Looking at the logs of the Swarm manager revealed an error that each node had an ID that was already used by the node currently in the cluster. time="2015-05-05T11:39:33Z" level=error msg="ID duplicated. AGM4:Z2ZA:NQW3:ZQ9K:IX34:JQJ1:SCAO:ECQL:PY4W:JVC3:C1YB:RZT6 shared by 172.30.5.100 and 172.30.5.101" When Docker starts it creates a trust key, which is then used to get an ID for the Docker daemon. You can find yours with: $ docker info | grep ID The problem occured due to a cloned VM image (with Docker and Swarm already installed) being used for each node. »

Using docker-gen with a Swarm cluster

TL;DR Using the latest version of docker-gen; connect it to the Swarm master (don’t forget SSL) and then use {{ $container.Node.Address.IP }} in your template files. docker-gen & Docker Swarm We will set up a Swarm cluster; in which nginx will be used as a reverse proxy to containers serving web content. docker-gen will monitor the swarm for relevant container starts and stops and update nginx accorrdingly. This in essense provides zero downtime for all container related maintenance. »