# Make a connection to the Swarm manager's API.  (Assumes port 2375 exposed for API)
master_connection = Docker::Swarm::Connection.new('http://10.20.30.1:2375')

# If swarm on the swarm master and using socket:
master_connection = Docker::Swarm::Connection.new('unix:///var/run/docker.sock')

 # Manager node intializes swarm
swarm_init_options = { "ListenAddr" => "0.0.0.0:2377" }
swarm = Docker::Swarm::Swarm.init(swarm_init_options, master_connection)

 # Gather all nodes available to swarm (overlay and bridges)
nodes = swarm.nodes()
expect(nodes.length).to eq 1

 # Worker joins swarm
worker_connection = Docker::Swarm::Connection.new('http://10.20.30.2:2375')
swarm.join_worker(worker_connection)

# Worker joins without master api connection
swarm_options = { "manager_ip" => "10.20.30.1", "node_ip" => "10.20.30.2", "JoinTokens" => {"Worker" => "FooBar" }}
swarm = Docker::Swarm::Swarm.new(swarm_options)
local_connection = Docker::Swarm::Connection.new('unix:///var/run/docker.sock')
swarm.join_worker(local_connection)

 # Join another manager to the swarm
manager_2_connection = Docker::Swarm::Connection.new('http://10.20.30.3:2375')
swarm.join_manager(manager_2_connection)

# Manager joins without master api connection
swarm_options = { "manager_ip" => "10.20.30.1", "node_ip" => "10.20.30.2", "JoinTokens" => {"Master" => "FooBar" }}
swarm = Docker::Swarm::Swarm.new(swarm_options)
local_connection = Docker::Swarm::Connection.new('unix:///var/run/docker.sock')
swarm.join_manager(local_connection)

 # Gather all nodes of swarm
nodes = swarm.nodes()

 # Create a network which connect services
network = swarm.create_overlay_network(network_name)

 # Find all networks in swarm cluster
networks = swarm.networks()

 # Create a service with 5 replicas
service_create_options = {"Name"=>"nginx",
 "TaskTemplate" =>
  {"ContainerSpec" =>
    {"Networks" => [], "Image" => "nginx:1.11.7", "Mounts" => [], "User" => "root"},
   "Env" => ["TEST_ENV=test"],
   "LogDriver" => {"Name"=>"json-file", "Options"=>{"max-file"=>"3", "max-size"=>"10M"}},
   "Placement" => {},
   "Resources" => {"Limits"=>{"MemoryBytes"=>104857600}, "Reservations"=>{}},
   "RestartPolicy" => {"Condition"=>"on-failure", "Delay"=>1, "MaxAttempts"=>3}},
 "Mode"=>{"Replicated" => {"Replicas" => 5}},
 "UpdateConfig" => {"Delay" => 2, "Parallelism" => 2, "FailureAction" => "pause"},
 "EndpointSpec"=>
  {"Ports" => [{"Protocol"=>"tcp", "PublishedPort" => 8181, "TargetPort" => 80}]},
 "Labels" => {"layer" => "database"},
 "Networks" => [{"Target" => "my-network"}]
}
service = swarm.create_service(service_create_options)

 # Retrieve all manager nodes of swarm
manager_nodes = swarm.manager_nodes()

 # Retrieve all worker nodes (that aren't managers)
worker_nodes = swarm.worker_nodes()

 # Drain a worker node - stop hosting tasks/containers of services
worker_node = worker_nodes.first
worker_node.drain()

 # Gather all tasks (containers for service) being hosted by the swarm cluster
tasks = swarm.tasks()

 # Scale up or down the number of replicas on a service
service.scale(20)

 # Worker leaves the swarm - no forcing
swarm.leave(worker_node, node)

 # Manager leaves the swarm - forced because last manager needs to use 'force' to leave the issue.
swarm.leave(manager_node, true)