docker-minecraft-server/elasticsearch

This Docker image provides an easily configurable Elasticsearch node. Via port mappings, it is easy to create an arbitrarily sized cluster of nodes. As long as the versions match, you can mix-and-match "real" Elasticsearch nodes with container-ized ones.

Basic Usage

To start an Elasticsearch data node that listens on the standard ports on your host's network interface:

docker run -d -p 9200:9200 -p 9300:9300 itzg/elasticsearch

You'll then be able to connect to the Elasticsearch HTTP interface to confirm it's alive:

http://DOCKERHOST:9200/

{
  "status" : 200,
  "name" : "Charon",
  "version" : {
    "number" : "1.3.5",
    "build_hash" : "4a50e7df768fddd572f48830ae9c35e4ded86ac1",
    "build_timestamp" : "2014-11-05T15:21:28Z",
    "build_snapshot" : false,
    "lucene_version" : "4.9"
  },
  "tagline" : "You Know, for Search"
}

Where DOCKERHOST would be the actual hostname of your host running Docker.

Basic multi-node cluster

Running a multi-node cluster (3-node in this example) is almost as easy:

docker run -d -p 9200:9200 -p 9300:9300 itzg/elasticsearch
docker run -d -p 9201:9200 -p 9301:9300 itzg/elasticsearch
docker run -d -p 9202:9200 -p 9302:9300 itzg/elasticsearch

where the only difference was the host port binding of 9200:/9300:, 9201:/9301:, and 9202:/9302:. By default, Elasticsearch uses Zen Discovery, so the three nodes find each other and form a cluster. You can confirm that by checking the cluster health for the presence of three nodes (number_of_nodes):

http://DOCKERHOST:9200/_cluster/health?pretty

{
  "cluster_name" : "elasticsearch",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 3,
  "number_of_data_nodes" : 3,
  "active_primary_shards" : 0,
  "active_shards" : 0,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0
}

Configuration

The following configuration options are specified using docker run environment variables (-e) like

docker run ... -e NAME=VALUE ... itzg/elasticsearch

Since Docker's -e settings are baked into the container definition, this image provides an extra feature to change any of the settings below for an existing container. Either create/edit the file env in the /conf volume mapping or edit within the running container's context using:

docker exec -it CONTAINER_ID vi /conf/env

replacing CONTAINER_ID with the container's ID or name.

The contents of the /conf/env file are standard shell

NAME=VALUE

entries where NAME is one of the variables described below.

Cluster Name

If joining a pre-existing cluster, then you may need to specify a cluster name different than the default "elasticsearch":

-e CLUSTER=dockers

Zen Unicast Hosts

When joining a multi-physical-host cluster, multicast may not be supported on the physical network. In that case, your node can reference specific one or more hosts in the cluster via the Zen Unicast Hosts capability as a comma-separated list of HOST:PORT pairs:

-e UNICAST_HOSTS=HOST:PORT[,HOST:PORT]

such as

-e UNICAST_HOSTS=192.168.0.100:9300

Plugins

You can install one or more plugins before startup by passing a comma-separated list of plugins.

-e PLUGINS=ID[,ID]

In this example, it will install the Marvel plugin

-e PLUGINS=elasticsearch/marvel/latest

Many more plugins are available here.

Publish As

Since the container gives the Elasticsearch software an isolated perspective of its networking, it will most likely advertise its published address with a container-internal IP address. This can be overridden with a physical networking name and port using:

-e PUBLISH_AS=DOCKERHOST:9301

Author Note: I have yet to hit a case where this was actually necessary. Other than the cosmetic weirdness in the logs, Elasticsearch seems to be quite tolerant.

Node Name

Rather than use the randomly assigned node name, you can indicate a specific one using:

-e NODE_NAME=Docker