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dockerdocker-machinedocker-swarm

Difference between docker machine with swarm options and running docker swarm init and join

I was trying to set up a cluster with docker swarm. However, I am a bit confused about how is docker-machine with swarm options different from initialising a swarm manager on one host and joining as workers from other hosts.

Here is an example for my question:

docker-machine with swarm options

docker-machine create --driver virtualbox --swarm --swarm-master --virtualbox-hostonly-cidr "10.0.0.1/24" node1
docker-machine create --driver virtualbox --swarm --swarm-discovery "token://..." --virtualbox-hostonly-cidr "10.0.0.1/24" node2
docker-machine create --driver virtualbox --swarm --swarm-discovery "token://..." --virtualbox-hostonly-cidr "10.0.0.1/24" node3

join a manager node as worker nodes

docker-machine create --driver virtualbox --virtualbox-hostonly-cidr "10.0.0.1/24" node1
docker-machine create --driver virtualbox --virtualbox-hostonly-cidr "10.0.0.1/24" node2
docker-machine create --driver virtualbox --virtualbox-hostonly-cidr "10.0.0.1/24" node3

eval $(docker-machine env node1)
docker swarm init

eval $(docker-machine env node2)
docker swarm join --token <token> <node1_IP>

eval $(docker-machine env node3)
docker swarm join --token <token> <node1_IP>
Solution

  • The first method you used is from old docker version when SWARM need to have a discovery key/value store setup

    docker-machine create --driver virtualbox --swarm --swarm-master --virtualbox-hostonly-cidr "10.0.0.1/24" node1
docker-machine create --driver virtualbox --swarm --swarm-discovery "token://..." --virtualbox-hostonly-cidr "10.0.0.1/24" node2
docker-machine create --driver virtualbox --swarm --swarm-discovery "token://..." --virtualbox-hostonly-cidr "10.0.0.1/24" node3

    The second method you had used is the Swarm mode

    To use Docker in swarm mode, install Docker 1.12.0 or later

    This was introduced in Docker 1.12.0. This is the method you should be using now as all new commands like docker service, docker stack require swarm mode. They won't work on the old one