Setting up a Swarm cluster

We'll continue using Docker Machine since it provides a very convenient way to simulate a cluster on a laptop. Three servers should be enough to demonstrate some of the key features of a Swarm cluster:

Note

All the commands from this chapter are available in the 02-docker-swarm.sh (https://gist.github.com/vfarcic/750fc4117bad9d8619004081af171896) Gist

for i in123; do
    docker-machine create -d virtualbox node-$i
done

At this moment, we have three nodes. Please note that those servers are not running anything but Docker Engine.

We can see the status of the nodes by executing the following ls command:

docker-machine ls

 

The output is as follows (ERROR column removed for brievity):

NAME   ACTIVE DRIVER  STATE   URL                        SWARM DOCKER
node-1 -  virtualbox  Running tcp://192.168.99.100:2376 v1.12.1
node-2 -  virtualbox  Running tcp://192.168.99.101:2376 v1.12.1
node-3 -  virtualbox  Running tcp://192.168.99.102:2376 v1.12.1

Figure 2-5: Machines running Docker...