Zookeeper

This is an image for apache zookeeper based on ubuntu:trusty docker image

Supported tags and respective Dockerfile links:

• 3.4.7, latest, circleci (Dockerfile)

Usage

The container has default environment variables that shouldn't be touched:

Environment Variable	Description	Value
ZOOKEEPER_HOME	home directory where zookeeper is installed	/opt/zookeeper/
ZOOKEEPER_CONFIG_FILE	configuration file for zookeeper	/opt/zookeeper/conf/zoo.cfg

To run container in standalone mode just don't set ZK_ID environment variable:

docker run -d -ti --publish 2181:2181 --name zookeeper vasylpurchel/zookeeper

Or it can be used in replicated mode:

docker run -d -ti -e ZK_CLIENT_PORT="2181" -e ZK_SERVERS="172.17.0.1:2888:3888 172.17.0.1:2889:3889 172.17.0.1:2890:3890" -e ZK_ID=1 --publish 2181:2181 --publish 2888:2888 --publish 3888:3888 --name zookeeper-node-1 vasylpurchel/zookeeper
...

To configure zookeeper instance you can use environment variables that starts with a same name as zookeeper configuration entries with ZK_ prefix, uppercase and words splitted by _

Few examples:

Environment Variable	Zookeeper Property
ZK_DATA_DIR	dataDir
ZK_TICK_TIME	tickTime
ZK_INIT_LIMIT	initLimit

By default only ZK_DATA_DIR is set to /tmp/zookeeper and in zoo.cfg file default values are:

Zookeeper Property	Default value
tickTime	2000
clientPort	2181
dataDir	/tmp/zookeeper

To save data you need to mount volume to ZK_DATA_DIR:

docker run -d -ti -v /data/zookeeper:/tmp/zookeeper --publish 2181:2181 --name zookeeper vasylpurchel/zookeeper

docker-entry-point.sh is generating configuration for container and runs any parameters after, so you can use this image to run other zookeeper related tasks and not only starting server in foreground(default one)

Notes

Make sure you are in zookeeper folder and that ip address in docker-compose.yml file is correct (mine is 127.17.0.1 while default is 127.17.42.1):

ifconfig | grep "docker0" -C 2 | grep "inet addr"

build image:

docker build -t vasylpurchel/zookeeper .

run 3 nodes from docker-compose:

docker-compose up

check that it works just run:

for i in {2181..2183}; do echo mntr | nc 172.17.0.1 $i | grep zk_followers ; done

TODO

• --net=host is used to tell docker containers to use host network, so this instances will be able to comunicate between themselves, need to be changed to overlay network so we can have multi-host network that will be using it