docker 实现redis集群搭建

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。

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

下载redis安装包，使用版本为：4.0.1

[[email protected] tmp]# mkdir docker_redis_cluster

[[email protected] tmp]# cd docker_redis_cluster/

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

解压编译redis

1

2

3

[[email protected] docker_redis_cluster]# tar zxvf redis-4.0.1.tar.gz

[[email protected] docker_redis_cluster]# cd redis-4.0.1/

[[email protected] redis-4.0.1]# make

修改redis配置

1	`[[email protected] 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

镜像制作

[[email protected] docker_redis_cluster]# cd /tmp/docker_redis_cluster

[[email protected] docker_redis_cluster]# vi Dockerfile

# Redis

# Version 4.0.1

FROM Centos:7<br data-filtered="filtered">

ENV REDIS_HOME /usr/local<br data-filtered="filtered">

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

构建镜像

# 切换中国源

[[email protected] docker_redis_cluster]# vi /etc/docker/daemon.json

{

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

}

# 编译

[[email protected] 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

查看镜像：

[[email protected] 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

基于此前制作的redis基础镜像创建一个redis节点镜像

[[email protected] tmp]# mkdir docker_redis_nodes

[[email protected] tmp]# cd docker_redis_nodes

[[email protected] docker_redis_nodes]# vi Dockerfile

# Redis Node

# Version 4.0.1<br data-filtered="filtered">

FROM hakimdstx/cluster-redis:4.0.1

# MAINTAINER_INFO

MAINTAINER hakim [email protected]

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

构建redis节点镜像

[[email protected] 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 [email protected]

---> 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

查看镜像

[[email protected] 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

三、运行redis集群

运行redis容器

[[email protected] docker_redis_nodes]# docker run -d --name redis-6379 -p 6379:6379 hakimdstx/nodes-redis:4.0.1

1673a7d859ea83257d5bf14d82ebf717fb31405c185ce96a05f597d8f855aa7d

[[email protected] docker_redis_nodes]# docker run -d --name redis-6380 -p 6380:6379 hakimdstx/nodes-redis:4.0.1

df6ebce6f12a6f3620d5a29adcfbfa7024e906c3af48f21fa7e1fa524a361362

[[email protected] docker_redis_nodes]# docker run -d --name redis-6381 -p 6381:6379 hakimdstx/nodes-redis:4.0.1

396e174a1d9235228b3c5f0266785a12fb1ea49efc7ac755c9e7590e17aa1a79

[[email protected] docker_redis_nodes]# docker run -d --name redis-6382 -p 6382:6379 hakimdstx/nodes-redis:4.0.1

d9a71dd3f969094205ffa7596c4a04255575cdd3acca2d47fe8ef7171a3be528

[[email protected] docker_redis_nodes]# docker run -d --name redis-6383 -p 6383:6379 hakimdstx/nodes-redis:4.0.1

73e4f843d8cb28595456e21b04f97d18ce1cdf8dc56d1150844ba258a3781933

[[email protected] docker_redis_nodes]# docker run -d --name redis-6384 -p 6384:6379 hakimdstx/nodes-redis:4.0.1

10c62aafa4dac47220daf5bf3cec84406f086d5261599b54ec6c56bb7da97d6d

查看容器信息

[[email protected] redis]# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

10c62aafa4da hakimdstx/nodes-redis:4.0.1 "/usr/local/redis/..." 3 seconds ago Up 2 seconds 0.0.0.0:6384->6379/tcp redis-6384

73e4f843d8cb hakimdstx/nodes-redis:4.0.1 "/usr/local/redis/..." 12 seconds ago Up 10 seconds 0.0.0.0:6383->6379/tcp redis-6383

d9a71dd3f969 hakimdstx/nodes-redis:4.0.1 "/usr/local/redis/..." 20 seconds ago Up 18 seconds 0.0.0.0:6382->6379/tcp redis-6382

396e174a1d92 hakimdstx/nodes-redis:4.0.1 "/usr/local/redis/..." 3 days ago Up 3 days 0.0.0.0:6381->6379/tcp redis-6381

df6ebce6f12a hakimdstx/nodes-redis:4.0.1 "/usr/local/redis/..." 3 days ago Up 3 days 0.0.0.0:6380->6379/tcp redis-6380

1673a7d859ea hakimdstx/nodes-redis:4.0.1 "/usr/local/redis/..." 3 days ago Up 3 days 0.0.0.0:6379->6379/tcp redis-6379

运行 redis 集群容器

通过远程连接，查看redis info replication 信息

[[email protected] ~]# redis-cli -h 192.168.10.52 -p 6379

192.168.10.52:6379> info replication

NOAUTH Authentication required.

192.168.10.52:6379> auth 123456

OK

192.168.10.52:6379> info replication

# Replication

role:master

connected_slaves:0

master_replid:2f0a7b50aed699fa50a79f3f7f9751a070c50ee9

master_replid2:0000000000000000000000000000000000000000

master_repl_offset:0

second_repl_offset:-1

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

192.168.10.52:6379>

# 其余基本信息同上

　　可以看到，客户连接之后，因为之前设置了密码，所以需要先输入密码认证，否则就无法通过。以上信息，我们知道所有的redis都是master角色 role:master ，这显然不是我们所希望的。

在配置之前我们需要查看所有容器当前的IP地址