Create an Elasticsearch cluster with one exposed node (with a Kopf panel installed) that acts as the "master" and a variable amount of "slave" (though they are eligible as masters, too) nodes.

docker-elasticsearch-cluster.sh

###
# Create an ElasticSearch cluster
###
ES_NODES_COUNT=4
HOSTS=es_master
for (( i=1; i<=$ES_NODES_COUNT; i++ )); do HOSTS=${HOSTS},es_node0$i; done
echo ${HOSTS}

# Create the first ES machine
docker run -d --name es_master \
    --net overlay \
    -v "es_master:/usr/share/elasticsearch/data" \
    -p "9200:9200" -p "9300:9300" \
    --env="constraint:node==swarm-master" \
    chialab/elasticsearch:manager \
        --node.name "Manager" \
        --discovery.zen.ping.multicast.enabled=false \
        --discovery.zen.ping.unicast.hosts=${HOSTS}

# Create the other nodes
for (( i=1; i<=$ES_NODES_COUNT; i++ )); do
    docker run -d --name es_node0$i \
        --net overlay \
        -v "es_node0$i:/usr/share/elasticsearch/data" \
        chialab/elasticsearch \
            --node.name "Node 0$i" \
            --discovery.zen.ping.multicast.enabled=false \
            --discovery.zen.ping.unicast.hosts=${HOSTS}
done