docker-zookeeper-cluster

A simple docker image to create a zookeeper cluster without much pain.

What is this used for?

There are several zookeeper docker images for creating standalone instances of zookeeper and running them. But there are no images that help in creating a zookeeper cluster across a single host or a multi-host environment. This image will help you to achieve the same.

Docker image

docker pull jeygeethan/zookeeper-cluster

Docker hub link

Looking for kafka cluster?

Go here : kafka-cluster

Zookeeper Cluster (multi-host)

Manual run of the cluster

Follow these steps:

1. Figure out if you will know the IP addresses/hosts of the hosts where you will be running the zookeepers containers.
2. UCP/Swarm - You can figure this out if you are using a constraint node (-e constraint:node==host_name) in your docker-compose.yml file
3. Disconnected hosts - You can figure this out by defining the set of hosts where you will deploy the container
4. Start running the containers in respective hosts or compile a sample docker-compose.yml as given below

Generic script to run the zookeeper container:

The example given below is for a three node cluster. Change the parameters to suit your needs. $ID means the id/number of the node (either 1,2,3 etc) you are currently trying to run.

docker run -d --restart=always \
      -p 2181:2181 \
      -p 2888:2888 \
      -p 3888:3888 \
      -v /var/lib/zookeeper:/var/lib/zookeeper \
      -v /var/log/zookeeper:/var/log/zookeeper  \
      jeygeethan/zookeeper-cluster zookeeper_1_ip_or_hostname,zookeeper_2_ip_or_hostname,zookeeper_3_ip_or_hostname $ID

Sample configuration for the three nodes:

Assume the three nodes are as follows:

1. docker_host_1
2. docker_host_2
3. docker_host_3

For first node (docker_host_1)

docker run -d --restart=always \
      -p 2181:2181 \
      -p 2888:2888 \
      -p 3888:3888 \
      -v /var/lib/zookeeper:/var/lib/zookeeper \
      -v /var/log/zookeeper:/var/log/zookeeper  \
      jeygeethan/zookeeper-cluster docker_host_1,docker_host_2,docker_host_3 1

For second node (docker_host_2)

docker run -d --restart=always \
      -p 2181:2181 \
      -p 2888:2888 \
      -p 3888:3888 \
      -v /var/lib/zookeeper:/var/lib/zookeeper \
      -v /var/log/zookeeper:/var/log/zookeeper  \
      jeygeethan/zookeeper-cluster docker_host_1,docker_host_2,docker_host_3 2

For third node (docker_host_3)

docker run -d --restart=always \
      -p 2181:2181 \
      -p 2888:2888 \
      -p 3888:3888 \
      -v /var/lib/zookeeper:/var/lib/zookeeper \
      -v /var/log/zookeeper:/var/log/zookeeper  \
      jeygeethan/zookeeper-cluster docker_host_1,docker_host_2,docker_host_3 3

Sample docker-compose.yml for the cluster creation

version: '2'
services:
  zk_1:
    image: jeygeethan/zookeeper-cluster
    container_name: zk_1
    ports:
      - '2181:2181'
      - '2888:2888'
      - '3888:3888'
    volumes:
      - /var/lib/zookeeper:/var/lib/zookeeper
      - /var/log/zookeeper:/var/log/zookeeper
    command: docker_host_1,docker_host_2,docker_host_3 1
    environment:
      - constraint:node==docker_host_1
    networks:
      - some_overlay_network
  zk_2:
    image: jeygeethan/zookeeper-cluster
    container_name: zk_2
    ports:
      - '2181:2181'
      - '2888:2888'
      - '3888:3888'
    volumes:
      - /var/lib/zookeeper:/var/lib/zookeeper
      - /var/log/zookeeper:/var/log/zookeeper
    command: docker_host_1,docker_host_2,docker_host_3 2
    environment:
      - constraint:node==docker_host_2
    networks:
      - some_overlay_network
  zk_3:
    image: jeygeethan/zookeeper-cluster
    container_name: zk_3
    ports:
      - '2181:2181'
      - '2888:2888'
      - '3888:3888'
    volumes:
      - /var/lib/zookeeper:/var/lib/zookeeper
      - /var/log/zookeeper:/var/log/zookeeper
    command: docker_host_1,docker_host_2,docker_host_3 3
    environment:
      - constraint:node==docker_host_3
    networks:
      - some_overlay_network
networks:
  some_overlay_network:
    external: true