Create and manage virtual docker swarm clusters in VirtualBox

Juan Gutiérrez-Aguado

• Preconditions
• Sample usage

This script uses docker-machine to provision a local virtual cluster in VirtualBox, starts docker swarm in the cluster, and installs the stack Portainer (http://portainer.io).

Besides, it creates a set of scripts to manage the created swarm cluster.

Preconditions

Linux host, docker, docker-machine and docker-machine-ipconfig (https://github.com/fivestars/docker-machine-ipconfig) to assign static IP addresses to the virtual machines.

Sample usage

# Cluster name
cluster="demo"

# Number of manager nodes in the swarm cluster
managers=1

# Number of worker nodes in the swarm cluster
workers=2

# Host only network in VirtualBox to connect the VMs
net="192.168.100.1/24"

# Directory to store generated cluster scripts
export CLUSTER_SCRIPTS_DIR=~/.docker/swarm

# Directory where required scripts can be found:
#
#  create_swarm_cluster.sh
#  docker-machine-ipconfig
BIN=~/bin/swarm
export PATH=$PATH:$BIN

# Memory to assign to manager VMs
export MANAGER_MEMORY=1024

# Memory to assign to worker VMs
export WORKER_MEMORY=1024

# Create the swarm cluster using VirtualBox
create_swarm_cluster $cluster $managers $workers $net

# List clusters
list_clusters

When the cluster is created and started, a directory ${CLUSTER_SCRIPTS_DIR}/${cluster} is created and contains the following scripts to manage the cluster:

• stop_cluster.sh to stop the cluster
• start_cluster.sh to start the cluster
• status_cluster.sh to check the status of the cluster
• add_worker.sh to create and add a new worker node to the cluster
• rm_worker.sh to delete a worker node from the cluster (this deletes the VM)
• rm_cluster.sh to delete the whole cluster (deleting all the VMs)

The following image shows a screenshoot of Portainer deployed in the cluster: