docker 实现redis集群搭建（一）

首先 我们需要理论知识 Redis Cluster是Redis的分布式解决方案 它解决了redis单机中心化的问题 分布式数据库——首要解决把整个数据集按照分区规则映射到多个节点的问题。

这边就需要知道分区规则——哈希分区规则。Redis Cluster 采用哈希分区规则中的虚拟槽分区。所有的键根据哈希函数映射到0 16383 计算公式 slot CRC16(key) 16383。每一个节点负责维护一部分槽以及槽所映射的键值数据。

一、创建redis docker基础镜像

1.下载redis安装包 使用版本为 4.0.1

[root etcd1 tmp]# mkdir docker_redis_cluster

[root etcd1 tmp]# cd docker_redis_cluster/

[root etcd2 docker_redis_cluster]# wget http://download.redis.io/releases/redis-4.0.1.tar.gz

2.解压编译redis

[root etcd1 docker_redis_cluster]# tar zxvf redis-4.0.1.tar.gz

[root etcd1 docker_redis_cluster]# cd redis-4.0.1/

[root etcd1 redis-4.0.1]# make

3.修改redis配置

[root etcd3 redis-4.0.1]# vi /tmp/docker_redis_cluster/redis-4.0.1/redis.conf

修改bind ip地址

# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the

# internet, binding to all the interfaces is dangerous and will expose the

# instance to everybody on the internet. So by default we uncomment the

# following bind directive, that will force Redis to listen only into

# the IPv4 lookback interface address (this means Redis will be able to

# accept connections only from clients running into the same computer it

# is running).

# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES

# JUST COMMENT THE FOLLOWING LINE.

# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#bind 127.0.0.1

bind 0.0.0.0

将守护进程yes改成no

# By default Redis does not run as a daemon. Use yes if you need it.

# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.

daemonize no

将密码项注释去掉 添加新密码

# Warning: since Redis is pretty fast an outside user can try up to

# 150k passwords per second against a good box. This means that you should

# use a very strong password otherwise it will be very easy to break.

# requirepass foobared

 修改为

# Warning: since Redis is pretty fast an outside user can try up to

# 150k passwords per second against a good box. This means that you should

# use a very strong password otherwise it will be very easy to break.

requirepass 123456

因为配置了密码 所以 配置中另外一处主从连接也需要配置密码

# If the master is password protected (using the requirepass configuration

# directive below) it is possible to tell the slave to authenticate before

# starting the replication synchronization process, otherwise the master will

# refuse the slave request.

# masterauth master-password 

 修改为

# If the master is password protected (using the requirepass configuration

# directive below) it is possible to tell the slave to authenticate before

# starting the replication synchronization process, otherwise the master will

# refuse the slave request.

# masterauth master-password 

masterauth 123456

设置日志路径

# Specify the log file name. Also the empty string can be used to force

# Redis to log on the standard output. Note that if you use standard

# output for logging but daemonize, logs will be sent to /dev/null

logfile /var/log/redis/redis-server.log 

 

配置集群相关信息 去掉配置项前面的注释

# Normal Redis instances can t be part of a Redis Cluster; only nodes that are

# started as cluster nodes can. In order to start a Redis instance as a

# cluster node enable the cluster support uncommenting the following:

cluster-enabled yes

# Every cluster node has a cluster configuration file. This file is not

# intended to be edited by hand. It is created and updated by Redis nodes.

# Every Redis Cluster node requires a different cluster configuration file.

# Make sure that instances running in the same system do not have

# overlapping cluster configuration file names.

cluster-config-file nodes-6379.conf

# Cluster node timeout is the amount of milliseconds a node must be unreachable

# for it to be considered in failure state.

# Most other internal time limits are multiple of the node timeout.

cluster-node-timeout 15000

4.镜像制作

[root etcd3 docker_redis_cluster]# cd /tmp/docker_redis_cluster

[root etcd3 docker_redis_cluster]# vi Dockerfile

# Redis

# Version 4.0.1

FROM Centos:7 br 

ENV REDIS_HOME /usr/local br 

ADD redis-4.0.1.tar.gz / # 本地的redis源码包复制到镜像的根路径下 ADD命令会在复制过后自动解包。被复制的对象必须处于Dockerfile同一路径 且ADD后面必须使用相对路径

RUN mkdir -p $REDIS_HOME/redis # 创建安装目录

ADD redis-4.0.1/redis.conf $REDIS_HOME/redis/ # 将一开始编译产生并修改后的配置复制到安装目录

RUN yum -y update # 更新yum源

RUN yum install -y gcc make # 安装编译需要的工具

WORKDIR /redis-4.0.1

RUN make

RUN mv /redis-4.0.1/src/redis-server $REDIS_HOME/redis/ # 编译后 容器中只需要可执行文件redis-server

WORKDIR /

RUN rm -rf /redis-4.0.1 # 删除解压文件

RUN yum remove -y gcc make # 安装编译完成之后 可以删除多余的gcc跟make

VOLUME [ /var/log/redis ] # 添加数据卷

EXPOSE 6379 # 暴露6379端口 也可以暴露多个端口 这里不需要如此

 

PS.当前镜像非可执行镜像 所以没有包含ENTRYPOINT和CMD指令

5.构建镜像

# 切换中国源

[root etcd3 docker_redis_cluster]# vi /etc/docker/daemon.json

 registry-mirrors : [ https://registry.docker-cn.com ]

[root etcd3 docker_redis_cluster]# docker build -t hakimdstx/cluster-redis .

Complete!

 --- 546cb1d34f35

Removing intermediate container 6b6556c5f28d

Step 14/15 : VOLUME /var/log/redis

 --- Running in 05a6642e4046

 --- e7e2fb8676b2

Removing intermediate container 05a6642e4046

Step 15/15 : EXPOSE 6379

 --- Running in 5d7abe1709e2

 --- 2d1322475f79

Removing intermediate container 5d7abe1709e2

Successfully built 2d1322475f79

 

镜像制作完成 制作中间可能会报 Public key for glibc-headers-2.17-222.el7.x86_64.rpm is not installed 错误 这时候需要在镜像配置中添加一句命令

...

RUN rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

RUN yum -y update # 更新yum源

RUN yum install -y gcc make # 安装编译需要的工具

6.查看镜像

[root etcd3 docker_redis_cluster]# docker images

REPOSITORY TAG IMAGE ID CREATED SIZE

hakimdstx/cluster-redis 4.0.1 1fca5a08a4c7 14 seconds ago 435 MB

centos 7 49f7960eb7e4 2 days ago 200 MB

以上 redis 基础镜像就制作完成了

二、制作redis节点镜像

1.基于此前制作的redis基础镜像创建一个redis节点镜像

[root etcd3 tmp]# mkdir docker_redis_nodes

[root etcd3 tmp]# cd docker_redis_nodes

[root etcd3 docker_redis_nodes]# vi Dockerfile

# Redis Node

# Version 4.0.1 br 

FROM hakimdstx/cluster-redis:4.0.1

# MAINTAINER_INFO

MAINTAINER hakim 1194842583 qq.com

ENTRYPOINT [ /usr/local/redis/redis-server , /usr/local/redis/redis.conf ]

2.构建redis节点镜像

[root etcd3 docker_redis_nodes]# docker build -t hakimdstx/nodes-redis:4.0.1 . 

Sending build context to Docker daemon 2.048 kB

Step 1/3 : FROM hakimdstx/cluster-redis:4.0.1

 --- 1fca5a08a4c7

Step 2/3 : MAINTAINER hakim 1194842583 qq.com

 --- Running in cc6e07eb2c36

 --- 55769d3bfacb

Removing intermediate container cc6e07eb2c36

Step 3/3 : ENTRYPOINT /usr/local/redis/redis-server /usr/local/redis/redis.conf

 --- Running in f5dedf88f6f6

 --- da64da483559

Removing intermediate container f5dedf88f6f6

Successfully built da64da483559

3.查看镜像

[root etcd3 docker_redis_nodes]# docker images

REPOSITORY TAG IMAGE ID CREATED SIZE

hakimdstx/nodes-redis 4.0.1 da64da483559 51 seconds ago 435 MB

hakimdstx/cluster-redis 4.0.1 1fca5a08a4c7 9 minutes ago 435 MB

centos 7 49f7960eb7e4 2 days ago 200 MB

docker 实现redis集群搭建（二） 摘要：接触docker以来，似乎养成了一种习惯，安装什么应用软件都想往docker方向做，今天就想来尝试下使用docker搭建redis集群。
  之前介绍了用docker来搭建redis主从环境，但这只是对数据添加了从库备份(主从复制)，当主库down掉的时候，从库是不会自动升级为主库的，也就是说，该redis主从集群并非是高可用的。
Lansonli CSDN大数据领域博客专家，华为云享专家、阿里云专家博主、腾云先锋（TDP）核心成员、51CTO专家博主，全网六万多粉丝，知名互联网公司大数据高级开发工程师