├── Dockerfile
├── README.md
└── zk-init.sh


/Dockerfile:
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 1 | FROM ubuntu:vivid
 2 | 
 3 | RUN apt-get update \
 4 |  && apt-get -y install git ant openjdk-8-jdk \
 5 |  && apt-get clean
 6 | RUN mkdir /tmp/zookeeper
 7 | WORKDIR /tmp/zookeeper
 8 | RUN git clone https://github.com/apache/zookeeper.git .
 9 | RUN git checkout release-3.5.1-rc2
10 | RUN ant jar
11 | RUN cp /tmp/zookeeper/conf/zoo_sample.cfg /tmp/zookeeper/conf/zoo.cfg
12 | RUN echo "standaloneEnabled=false" >> /tmp/zookeeper/conf/zoo.cfg
13 | RUN	echo "dynamicConfigFile=/tmp/zookeeper/conf/zoo.cfg.dynamic" >> /tmp/zookeeper/conf/zoo.cfg
14 | ADD zk-init.sh /usr/local/bin/
15 | ENTRYPOINT ["/usr/local/bin/zk-init.sh"]
16 | 


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/README.md:
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 1 | #Zookeeper
 2 | 
 3 | This Docker image contains Zookeeper 3.5.1-rc2 which features dynamic host reconfiguration. Upon start, it attempts to join an existing cluster.
 4 | 
 5 | The syntax to start a container is like this:
 6 | 
 7 |   `docker run --net host --name [name] containersol/zookeeper [id] [ip]`
 8 |   
 9 | where 
10 |   - `id` = id of the zookeeper node (known internally as myid)
11 |   - `ip` = ip address of a node of the existing cluster
12 |   
13 | The `id` is mandatory, the `ip` is optional.
14 | 
15 | The `--net host` is needed for zookeepers on different hosts to be able to contact each other.
16 | 


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/zk-init.sh:
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 1 | #!/bin/bash
 2 | 
 3 | ZK=$1
 4 | MYID=1
 5 | IPADDRESS=`ip -4 addr show scope global dev eth0 | grep inet | awk '{print \$2}' | cut -d / -f 1`
 6 | 
 7 | cd /tmp/zookeeper
 8 | if [ -n "$ZK" ] 
 9 | then
10 |   output=`./bin/zkCli.sh -server $ZK:2181 get /zookeeper/config | grep ^server` 
11 |   
12 |   # extract all the zk-ids from the output
13 |   declare -a id_list=()
14 |   while read x;
15 |   do
16 |     id_list+=(`echo $x | cut -d"=" -f1 | cut -d"." -f2`)
17 |   done <<<$(output)
18 |   sorted_id_list=( $(
19 |     for el in "${id_list[@]}"
20 |     do  
21 |       echo "$el"
22 |     done | sort -n) )
23 |   
24 |   # get the next increasing number from the sequence
25 |   MYID=$((${sorted_id_list[${#sorted_id_list[@]}-1]}+1))
26 |   echo $output >> /tmp/zookeeper/conf/zoo.cfg.dynamic
27 |   echo "server.$MYID=$IPADDRESS:2888:3888:observer;2181" >> /tmp/zookeeper/conf/zoo.cfg.dynamic
28 |   cp /tmp/zookeeper/conf/zoo.cfg.dynamic /tmp/zookeeper/conf/zoo.cfg.dynamic.org
29 |   /tmp/zookeeper/bin/zkServer-initialize.sh --force --myid=$MYID
30 |   ZOO_LOG_DIR=/var/log ZOO_LOG4J_PROP='INFO,CONSOLE,ROLLINGFILE' /tmp/zookeeper/bin/zkServer.sh start
31 |   /tmp/zookeeper/bin/zkCli.sh -server $ZK:2181 reconfig -add "server.$MYID=$IPADDRESS:2888:3888:participant;2181"
32 |   /tmp/zookeeper/bin/zkServer.sh stop
33 |   ZOO_LOG_DIR=/var/log ZOO_LOG4J_PROP='INFO,CONSOLE,ROLLINGFILE' /tmp/zookeeper/bin/zkServer.sh start-foreground
34 | else
35 |   echo "server.$MYID=$IPADDRESS:2888:3888;2181" >> /tmp/zookeeper/conf/zoo.cfg.dynamic
36 |   /tmp/zookeeper/bin/zkServer-initialize.sh --force --myid=$MYID
37 |   ZOO_LOG_DIR=/var/log ZOO_LOG4J_PROP='INFO,CONSOLE,ROLLINGFILE' /tmp/zookeeper/bin/zkServer.sh start-foreground
38 | fi
39 | 


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