zookeeper3.4.6をdocker-composeで起動させる

docker-composeでzookeeperクラスターを立てるって本当に簡単にできるよね。
公式ドキュメントみれば、最新のイメージを使用してすぐにクラスターを構築できます。

公式がサポートしていないzookeeperのバージョンを使用したい時、
自分でイメージから作り直す必要があります。
現状dockerhubから取得できるのは3.4.9までです。

今回は、それより古いバージョンであるzookeeper3.4.6のイメージを作成します。

事前準備

baseとするdocker imageはopenjdk:8-jre-alpineです。
準備するものは4つです。
・Dockerfile
・docker-compose.yml
・docker-entrypoint.sh
・zookeeper-3.4.6.tar.gz

Dockerfile

FROM openjdk:8-jre-alpine
LABEL noffuy <3330072-noffuy@users.noreply.gitlab.com>

# Install required packages
RUN apk add --no-cache \
    bash \
    su-exec

ENV ZOO_USER=zookeeper \
    ZOO_CONF_DIR=/conf \
    ZOO_DATA_DIR=/data \
    ZOO_DATA_LOG_DIR=/datalog \
    ZOO_LOG_DIR=/logs \
    ZOO_PORT=2181 \
    ZOO_TICK_TIME=2000 \
    ZOO_INIT_LIMIT=5 \
    ZOO_SYNC_LIMIT=2 \
    ZOO_AUTOPURGE_PURGEINTERVAL=0 \
    ZOO_AUTOPURGE_SNAPRETAINCOUNT=3 \
    ZOO_MAX_CLIENT_CNXNS=60

# Add a user and make dirs
RUN set -ex; \
    adduser -D "$ZOO_USER"; \
    mkdir -p "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"; \
    chown "$ZOO_USER:$ZOO_USER" "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"

ARG GPG_KEY=C61B346552DC5E0CB53AA84F59147497767E7473
ARG DISTRO_NAME=zookeeper-3.4.6

# Download Apache Zookeeper, verify its PGP signature, untar and clean up
COPY ./zookeeper-3.4.6.tar.gz /
RUN set -ex; \
    apk add --no-cache --virtual .build-deps \
        ca-certificates \
        gnupg \
        libressl; \
    tar -xzf "$DISTRO_NAME.tar.gz"; \
    mv "$DISTRO_NAME/conf/"* "$ZOO_CONF_DIR"; \
    rm -rf "$GNUPGHOME" "$DISTRO_NAME.tar.gz" \
    apk del .build-deps

WORKDIR $DISTRO_NAME
VOLUME ["$ZOO_DATA_DIR", "$ZOO_DATA_LOG_DIR", "$ZOO_LOG_DIR"]

EXPOSE $ZOO_PORT 2888 3888

FROM openjdk:8-jre-alpine

LABEL noffuy <3330072-noffuy@users.noreply.gitlab.com>

# Install required packages

RUN apk add --no-cache \

bash \

su-exec

ENV ZOO_USER=zookeeper \

ZOO_CONF_DIR=/conf \

ZOO_DATA_DIR=/data \

ZOO_DATA_LOG_DIR=/datalog \

ZOO_LOG_DIR=/logs \

ZOO_PORT=2181 \

ZOO_TICK_TIME=2000 \

ZOO_INIT_LIMIT=5 \

ZOO_SYNC_LIMIT=2 \

ZOO_AUTOPURGE_PURGEINTERVAL=0 \

ZOO_AUTOPURGE_SNAPRETAINCOUNT=3 \

ZOO_MAX_CLIENT_CNXNS=60

# Add a user and make dirs

RUN set -ex; \

adduser -D "$ZOO_USER"; \

mkdir -p "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"; \

chown "$ZOO_USER:$ZOO_USER" "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"

ARG GPG_KEY=C61B346552DC5E0CB53AA84F59147497767E7473

ARG DISTRO_NAME=zookeeper-3.4.6

# Download Apache Zookeeper, verify its PGP signature, untar and clean up

COPY ./zookeeper-3.4.6.tar.gz /

RUN set -ex; \

apk add --no-cache --virtual .build-deps \

ca-certificates \

gnupg \

libressl; \

tar -xzf "$DISTRO_NAME.tar.gz"; \

mv "$DISTRO_NAME/conf/"* "$ZOO_CONF_DIR"; \

rm -rf "$GNUPGHOME" "$DISTRO_NAME.tar.gz" \

apk del .build-deps

WORKDIR $DISTRO_NAME

VOLUME ["$ZOO_DATA_DIR", "$ZOO_DATA_LOG_DIR", "$ZOO_LOG_DIR"]

EXPOSE $ZOO_PORT 2888 3888

このDockerfileを利用してdocker-composeで起動します。

docker-compose.yml

version: '3'
services:
    zoo1:
        build: ./
        restart: always
        ports:
            - 2181:2181
        volumes:
            - ./log:/logs
        environment:
            ZOO_MY_ID: 1
            ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888
            ZOO_TICK_TIME: 4000
            ZOO_INIT_LIMIT: 10
            ZOO_LOG4J_PROP: INFO,ROLLINGFILE

    zoo2:
        build: ./
        restart: always
        ports:
            - 2182:2181
        volumes:
            - ./log:/logs
        environment:
            ZOO_MY_ID: 2
            ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888
            ZOO_TICK_TIME: 4000
            ZOO_INIT_LIMIT: 10
            ZOO_LOG4J_PROP: INFO,ROLLINGFILE

    zoo3:
        build: ./
        restart: always
        ports:
            - 2183:2181
        volumes:
            - ./log:/logs
        environment:
            ZOO_MY_ID: 3
            ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888
            ZOO_TICK_TIME: 4000
            ZOO_INIT_LIMIT: 10
            ZOO_LOG4J_PROP: INFO,ROLLINGFILE

version: '3'

services:

zoo1:

build: ./

restart: always

ports:

- 2181:2181

volumes:

- ./log:/logs

environment:

ZOO_MY_ID: 1

ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

ZOO_TICK_TIME: 4000

ZOO_INIT_LIMIT: 10

ZOO_LOG4J_PROP: INFO,ROLLINGFILE

zoo2:

build: ./

restart: always

ports:

- 2182:2181

volumes:

- ./log:/logs

environment:

ZOO_MY_ID: 2

ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

ZOO_TICK_TIME: 4000

ZOO_INIT_LIMIT: 10

ZOO_LOG4J_PROP: INFO,ROLLINGFILE

zoo3:

build: ./

restart: always

ports:

- 2183:2181

volumes:

- ./log:/logs

environment:

ZOO_MY_ID: 3

ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

ZOO_TICK_TIME: 4000

ZOO_INIT_LIMIT: 10

ZOO_LOG4J_PROP: INFO,ROLLINGFILE

docker-entrypoint.sh

次にdocker-entrypoint.shを作成します。

#!/bin/bash

set -e

# Allow the container to be started with `--user`
if [[ "$1" = 'zkServer.sh' && "$(id -u)" = '0' ]]; then
    chown -R "$ZOO_USER" "$ZOO_DATA_DIR" "$ZOO_DATA_LOG_DIR" "$ZOO_LOG_DIR" "$ZOO_CONF_DIR"
    exec su-exec "$ZOO_USER" "$0" "$@"
fi

# Generate the config only if it doesn't exist
if [[ ! -f "$ZOO_CONF_DIR/zoo.cfg" ]]; then
    CONFIG="$ZOO_CONF_DIR/zoo.cfg"

    echo "clientPort=$ZOO_PORT" >> "$CONFIG"
    echo "dataDir=$ZOO_DATA_DIR" >> "$CONFIG"
    echo "dataLogDir=$ZOO_DATA_LOG_DIR" >> "$CONFIG"

    echo "tickTime=$ZOO_TICK_TIME" >> "$CONFIG"
    echo "initLimit=$ZOO_INIT_LIMIT" >> "$CONFIG"
    echo "syncLimit=$ZOO_SYNC_LIMIT" >> "$CONFIG"

    echo "autopurge.snapRetainCount=$ZOO_AUTOPURGE_SNAPRETAINCOUNT" >> "$CONFIG"
    echo "autopurge.purgeInterval=$ZOO_AUTOPURGE_PURGEINTERVAL" >> "$CONFIG"
    echo "maxClientCnxns=$ZOO_MAX_CLIENT_CNXNS" >> "$CONFIG"

    for server in $ZOO_SERVERS; do
        echo "$server" >> "$CONFIG"
    done
fi

# Write myid only if it doesn't exist
if [[ ! -f "$ZOO_DATA_DIR/myid" ]]; then
    echo "${ZOO_MY_ID:-1}" > "$ZOO_DATA_DIR/myid"
fi

exec "$@"

#!/bin/bash

set -e

# Allow the container to be started with `--user`

if [[ "$1" = 'zkServer.sh' && "$(id -u)" = '0' ]]; then

chown -R "$ZOO_USER" "$ZOO_DATA_DIR" "$ZOO_DATA_LOG_DIR" "$ZOO_LOG_DIR" "$ZOO_CONF_DIR"

exec su-exec "$ZOO_USER" "$0" "$@"

# Generate the config only if it doesn't exist

if [[ ! -f "$ZOO_CONF_DIR/zoo.cfg" ]]; then

CONFIG="$ZOO_CONF_DIR/zoo.cfg"

echo "clientPort=$ZOO_PORT" >> "$CONFIG"

echo "dataDir=$ZOO_DATA_DIR" >> "$CONFIG"

echo "dataLogDir=$ZOO_DATA_LOG_DIR" >> "$CONFIG"

echo "tickTime=$ZOO_TICK_TIME" >> "$CONFIG"

echo "initLimit=$ZOO_INIT_LIMIT" >> "$CONFIG"

echo "syncLimit=$ZOO_SYNC_LIMIT" >> "$CONFIG"

echo "autopurge.snapRetainCount=$ZOO_AUTOPURGE_SNAPRETAINCOUNT" >> "$CONFIG"

echo "autopurge.purgeInterval=$ZOO_AUTOPURGE_PURGEINTERVAL" >> "$CONFIG"

echo "maxClientCnxns=$ZOO_MAX_CLIENT_CNXNS" >> "$CONFIG"

for server in $ZOO_SERVERS; do

echo "$server" >> "$CONFIG"

done

# Write myid only if it doesn't exist

if [[ ! -f "$ZOO_DATA_DIR/myid" ]]; then

echo "${ZOO_MY_ID:-1}" > "$ZOO_DATA_DIR/myid"

exec "$@"

zookeeper-3.4.6.tar.gz

人によってはバージョンをもっと古いやつを使う人もいるかも知れません。
その時は、Dockerfileを適宜修正してね。
下記からダウンロードして下さい。
https://archive.apache.org/dist/zookeeper/zookeeper-3.4.6/zookeeper-3.4.6.tar.gz

この4つを準備したら
ディレクトリはこんな感じになります。

$ tree
.
├── docker-compose.yml
├── docker-entrypoint.sh
├── Dockerfile
└── zookeeper-3.4.6.tar.gz

$ tree

├── docker-compose.yml

├── docker-entrypoint.sh

├── Dockerfile

└── zookeeper-3.4.6.tar.gz

docker-compose up -d で起動すればオッケーです。
./log/配下にログが出力されるのでそこで確認して下さい。

本番で使えるかはまだ怪しいですが
開発・テスト環境などで大活躍

じゃあね〜〜〜〜。