Script to bootstrap multihost swarm with Docker Machine (DIGITALOCEAN_ACCESS_TOKEN env var must be set, and experimental client binary available as dockerx locally)

bootstrap-multihost.sh

#!/bin/bash

set -e

# Create this many swarm workers
export N_WORKERS=1

# Coloring info
export bold=$(tput bold)
export normal=$(tput sgr0)

function neighbor_ip_option() {
    # Only set the neighbor IP for the nodes created after the first.
    if [[ "$1" != "swarm-0" ]]; then
        echo "--engine-label com.docker.network.driver.overlay.neighbor_ip=$(docker-machine ip swarm-0)"
    fi
}

# Bring up a machine using the overlay network for every container
function create_mcn_on_overlay() {
    docker-machine --debug create \
        -d digitalocean \
        --digitalocean-image ubuntu-14-10-x64 \
        --digitalocean-region sfo1 \
        --engine-install-url experimental.docker.com \
        --engine-opt kv-store=consul:$(docker-machine ip consul):8500 \
        --engine-opt default-network=overlay:multihost \
        --engine-label com.docker.network.driver.overlay.bind_interface=eth0 \
        $(neighbor_ip_option "$1") \
        "$1" | awk -v prefix="${bold}$1 => ${normal}" '{print prefix $0}'
}

# Join the created swarm with the machine of a given name
function mcn_join_swarm() {
    dockerx $(docker-machine config "$1") run -d \
        --restart always \
        --net bridge \
        swarm:latest join --addr $(docker-machine ip "$1"):2376 token://$SWARM_TOKEN
}

# Create droplet used to run Consul
docker-machine --debug create \
    -d digitalocean \
    --digitalocean-region sfo1 \
    --engine-install-url experimental.docker.com \
    consul

# Run Consul container used for service discovery
dockerx $(docker-machine config consul) run -d \
    -p 8500:8500 \
    -h consul \
    progrium/consul -server -bootstrap

# First create swarm master
create_mcn_on_overlay "swarm-0"

# Then create swarm workers
for i in $(seq 1 "$N_WORKERS"); do
    mcn_name="swarm-$i"
    create_mcn_on_overlay "$mcn_name" &
done

# Wait for creates to finish
wait

export SWARM_TOKEN=$(dockerx $(docker-machine config consul) run swarm create)

# Run Swarm master / manager container
dockerx $(docker-machine config swarm-0) run -d \
    --restart always \
    --net bridge \
    -p 3376:3376 \
    -v /etc/docker:/etc/docker \
    swarm:latest manage \
        --tlsverify \
        --tlscacert="/etc/docker/ca.pem" \
        --tlscert="/etc/docker/server.pem" \
        --tlskey="/etc/docker/server-key.pem" \
        -H "tcp://0.0.0.0:3376" \
        --strategy spread \
        "token://$SWARM_TOKEN"

for i in $(seq 0 "$N_WORKERS"); do
    mcn_name="swarm-$i"
    echo "Joining ${mcn_name} to the Swarm..."
    mcn_join_swarm ${mcn_name}
done