Docker学习重点(8)~Docker网络


一、Docker网络--理解Docker0

  • 准备工作：清空所有环境
    • 将docker 的所有镜像、容器先删除，干干净净！

1、查看本地网络信息 ip addr

● 可见有三个网卡信息：

  • lo：本地(回环)地址；
  • ens：虚拟机或阿里云服务器(内网)地址；
  • docker0：docker网络地址。

● 问题：docker 是如何处理容器网络访问的？


2、查看docker容器启动时的内部网络 ip addr

● Docker容器没有ip addr命令：exec ip addr 报错：

OCI runtime exec failed: exec failed: container_linux.go:380: starting container process caused: exec: "ip": executable file not found in $PATH: unknown

《exec failed: exec failed..... exec: “ip“（Docker容器没有ip addr命令：ex(Docker容器没有ip addr命令：exec ip addr 报错)的解决》


☺ ip addr 命令成功执行：

[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat01 ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
6: eth0@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever

3、docker 容器和linux 系统宿主机可以相互ping 通

# tomcat 容器 ping 通宿主机(外网地址 120.76.136.52， 内网地址 172.22.26.169)
root@f1cfb81dedfd:/usr/local/tomcat# ping 120.76.136.52
PING 120.76.136.52 (120.76.136.52) 56(84) bytes of data.
64 bytes from 120.76.136.52: icmp_seq=1 ttl=63 time=2.97 ms
64 bytes from 120.76.136.52: icmp_seq=2 ttl=63 time=2.89 ms

root@f1cfb81dedfd:/usr/local/tomcat# ping 172.22.26.169
PING 172.22.26.169 (172.22.26.169) 56(84) bytes of data.
64 bytes from 172.22.26.169: icmp_seq=1 ttl=64 time=0.088 ms
64 bytes from 172.22.26.169: icmp_seq=2 ttl=64 time=0.072 ms
64 bytes from 172.22.26.169: icmp_seq=3 ttl=64 time=0.086 ms

# 宿主机ping 通 tomcat 容器（tomcat 的网卡地址 172.17.0.2）
[root@iZwz9535z41cmgcpkm7i81Z ~]# ping 172.17.0.2
PING 172.17.0.2 (172.17.0.2) 56(84) bytes of data.
64 bytes from 172.17.0.2: icmp_seq=1 ttl=64 time=0.106 ms
64 bytes from 172.17.0.2: icmp_seq=2 ttl=64 time=0.083 ms

4、docker 容器互联的原理：

docker每启动一个容器，就会分配一个ip，只要安装了docker，就会有一个网卡docker0，桥接模式，使用的时veth-pair技术。

  • docker 容器内部，查询ip信息：

● 容器 ip 命令，没有找到：bash: ping: command not found

  • 解决：安装iputils-ping，命令：apt -y install iputils-ping

  • 宿主机，查询ip信息：

■ 再启动一个容器, 宿主机查看ip信息：发现又多了一对网卡

[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat02 ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
16: eth0@if17: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:00:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.3/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever

可以看到容器内ip与本机ip成对出现，这就是veth-pair技术。

  • 我们发现这个容器带来网卡，都是一对对的。

  • evth—pair 就是一对的虚拟设备接口，他们都是成对出现的，一段连着协议，一段彼此相连。正因为有这个特性，evth—pair 充当一个桥梁，连接各种虚拟网络设备的。

  • openstac，Docker容器之间的连接，OVS的连接，都是使用 evth-pair 技术 。


5、容器与容器之间可以相互ping 通，使用evth-pair 技术：

# tomcat01 容器ping tomcat02 容器
root@f1cfb81dedfd:/usr/local/tomcat# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
6: eth0@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever
root@f1cfb81dedfd:/usr/local/tomcat# ping 172.17.0.3
PING 172.17.0.3 (172.17.0.3) 56(84) bytes of data.
64 bytes from 172.17.0.3: icmp_seq=1 ttl=64 time=0.125 ms

# tomcat02 容器ping tomcat01 容器
root@23254b923487:/usr/local/tomcat# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
16: eth0@if17: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:00:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.3/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever
root@23254b923487:/usr/local/tomcat# ping 172.17.0.2
PING 172.17.0.2 (172.17.0.2) 56(84) bytes of data.
64 bytes from 172.17.0.2: icmp_seq=1 ttl=64 time=0.136 ms
64 bytes from 172.17.0.2: icmp_seq=2 ttl=64 time=0.105 ms

docker0相当于一个路由器，各个容器都与docker0相连，容器之间的通信通过路由器来转发。

■ 结论：容器tomcat01和容器tomcat02是公用的一个路由器，docker0。

  • 所有的容器不指定网络的情况下，都是docker0路由的，docker会给我们的容器分配一个默认的可用IP

  • docker0：


  • evth-pair 技术:
    • Docker 使用的是Linux的桥接，宿主机中 是一个docker 容器的网桥 docker0。
    • Docker中的所有网络接口都是虚拟的(虚拟转发的效率高)，相当于内网传递；
    • 只要删除容器，对应网络就会删除。



二、容器互联技术 ● --link

1、(高可用问题)需求: database url = ip;

每次重启容器或Linux，ip就会变化，固定的ip互联网络就会失效，如何使用服务名来连接，而不考虑ip？

---可以通过名字来访问容器。


2、测试使用容器名来ping

[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat02 ping tomcat01
ping: tomcat01: Name or service not known
  • 容器之间无法通过容器名来连接；如何解决？
# 通过 --link 就可以解决了网络连通问题(通过名字连通)
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker run -d -P --name tomcat03 --link tomcat02 tomcat:9.0
81d38e78eea0756c654af6b51ac626ad7c086a7fe56589303ddb108fd0091f8d
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat03 ping tomcat02 
PING tomcat02 (172.17.0.3) 56(84) bytes of data.
64 bytes from tomcat02 (172.17.0.3): icmp_seq=1 ttl=64 time=0.182 ms
64 bytes from tomcat02 (172.17.0.3): icmp_seq=2 ttl=64 time=0.082 ms

# 但是反向却无法链接通！！！(因为创建tomcat02 的时候，并没有--link tomcat03)
# tomcat02 想通过名字 ping tomcat03
root@23254b923487:/usr/local/tomcat# ping tomcat03
ping: tomcat03: Name or service not known

3、docker network 命令：

  • 探究命令 inspect

  • inspect tomcat03：


  • 进入tomcat03，查看它的主机文件hosts：


4、tomcat03能够通过容器名链接tomcat02的原理：

通过--link，tomcat03在自己容器hosts文件中配置了tomcat02 的ip信息！

[root@node1 ~]# docker exec -it tomcat03 cat /etc/hosts
127.0.0.1	localhost
::1	localhost ip6-localhost ip6-loopback
fe00::0	ip6-localnet
ff00::0	ip6-mcastprefix
ff02::1	ip6-allnodes
ff02::2	ip6-allrouters
172.17.0.3	tomcat02 23254b923487
172.17.0.4	373a2f03bd8d

# --link 在咱的hosts 配置中增加了一个 172.17.0.3	tomcat02 23254b923487   直接写死的

● 本质就是修改host映射，--link已经摒弃；建议实现使用自定义网络实现！

  • 不使用 --link，不使用网桥docker0
    • 因为：docker0的问题：不支持容器名连接访问!



三、容器互联技术 ● 自定义网络

● network 命令：

[root@iZwz9535z41cmgcpkm7i81Z ~]# docker network --help 

Usage:  docker network COMMAND

Manage networks

Commands:
  connect     Connect a container to a network
  create      Create a network
  disconnect  Disconnect a container from a network
  inspect     Display detailed information on one or more networks
  ls          List networks
  prune       Remove all unused networks
  rm          Remove one or more networks

Run 'docker network COMMAND --help' for more information on a command.

1、查看所有的docker网络 docker network ls

[root@iZwz9535z41cmgcpkm7i81Z ~]# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
8ddb7e9846c6   bridge    bridge    local
48e785b7efb3   host      host      local
7e07c5b5ae34   none      null      local

2、网络模式：

  • bridge : 桥接（默认，自己创建也使用bridge 模式）
  • host ： 和宿主即共享网络
  • none ： 不配置网络
  • container：容器网络连通!(很少用，局限性很大！)

3、测试自定义网络

# 原先启动容器，其实是默认使用docker0 [--net bridge]，桥接模式
docker run -d -P --name tomcat01 tomcat:9.0
# 实际上是
docker run -d -P --name tomcat01 --net bridge tomcat:9.0

# docker0 特点：默认，但是对于域名无法访问，不过可以通过--link打通连接
  • 创建自定义的网络 docker create
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker network create --help

Usage:  docker network create [OPTIONS] NETWORK

Create a network

Options:
      --attachable           Enable manual container attachment
      --aux-address map      Auxiliary IPv4 or IPv6 addresses used by Network driver (default map[])
      --config-from string   The network from which to copy the configuration
      --config-only          Create a configuration only network
  -d, --driver string        Driver to manage the Network (default "bridge")
      --gateway strings      IPv4 or IPv6 Gateway for the master subnet
      --ingress              Create swarm routing-mesh network
      --internal             Restrict external access to the network
      --ip-range strings     Allocate container ip from a sub-range
      --ipam-driver string   IP Address Management Driver (default "default")
      --ipam-opt map         Set IPAM driver specific options (default map[])
      --ipv6                 Enable IPv6 networking
      --label list           Set metadata on a network
  -o, --opt map              Set driver specific options (default map[])
      --scope string         Control the network's scope
      --subnet strings       Subnet in CIDR format that represents a network segment


----------------------------------------------------------------------------------------------------------------------------

# 命令参数详解
[root@node1 ~]# docker network create --help

Usage:  docker network create [OPTIONS] NETWORK

Create a network

Options:
      --attachable           Enable manual container attachment
      --aux-address map      Auxiliary IPv4 or IPv6 addresses used by Network driver (default map[])
      --config-from string   The network from which to copy the configuration
      --config-only          Create a configuration only network
  -d, --driver string        Driver to manage the Network (default "bridge")
      --gateway strings      IPv4 or IPv6 Gateway for the master subnet
      --ingress              Create swarm routing-mesh network
      --internal             Restrict external access to the network
      --ip-range strings     Allocate container ip from a sub-range
      --ipam-driver string   IP Address Management Driver (default "default")
      --ipam-opt map         Set IPAM driver specific options (default map[])
      --ipv6                 Enable IPv6 networking
      --label list           Set metadata on a network
  -o, --opt map              Set driver specific options (default map[])
      --scope string         Control the network's scope
      --subnet strings       Subnet in CIDR format that represents a network segment
  • 创建一个网络 mynet：

  • 自定义网络创建完成:

  • 检查创建的网络：


  • 创建容器的时候，连接自定义的网络mynet

    • 不同容器同处于同一网络下mynet，维护好了容器间的关系


4、通过名字，容器之间相互ping

# 现在不使用 --link，也可以ping 名字了

# 通过名字 tomcat-net-01 ping tomcat-net-02
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat-net-01 ping tomcat-net-02
PING tomcat-net-02 (192.168.0.3) 56(84) bytes of data.
64 bytes from tomcat-net-02.mynet (192.168.0.3): icmp_seq=1 ttl=64 time=0.102 ms
64 bytes from tomcat-net-02.mynet (192.168.0.3): icmp_seq=2 ttl=64 time=0.064 ms
64 bytes from tomcat-net-02.mynet (192.168.0.3): icmp_seq=3 ttl=64 time=0.062 ms
64 bytes from tomcat-net-02.mynet (192.168.0.3): icmp_seq=4 ttl=64 time=0.070 ms
^C
--- tomcat-net-02 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 2999ms
rtt min/avg/max/mdev = 0.062/0.074/0.102/0.016 ms


# 通过名字 tomcat-net-02 ping tomcat-net-01
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat-net-02 ping tomcat-net-01
PING tomcat-net-01 (192.168.0.2) 56(84) bytes of data.
64 bytes from tomcat-net-01.mynet (192.168.0.2): icmp_seq=1 ttl=64 time=0.123 ms
64 bytes from tomcat-net-01.mynet (192.168.0.2): icmp_seq=2 ttl=64 time=0.074 ms
^C
--- tomcat-net-01 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.074/0.098/0.123/0.024 ms

5、自定义网络的意义：

我们自定义的网络docker都已经帮我们维护好了对应的关系。可以实现不同集群使用不同的网络，保证集群网络的安全和健康。

  • 如Redis集群在192.160.0.0/16网段下,mysql集群在192.161.0.0/16网段下。



四、网络连通

1、场景：tomcat01 ping tomcat-net-01,无法ping 通


2、使用docker network connect：

[root@iZwz9535z41cmgcpkm7i81Z ~]# docker network connect  mynet tomcat01
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker network inspect mynet


■ 可以看到mynet将tomcat01容器添加到自己网络中：

  • 测试打通 tomcat01-mynet
  • 连通之后就是将 tomcat01 放到了 mynet 网络下？＃一个容器两个ip地址！
    • 阿里云服务：公网ip 私网ip

■ 网卡与网卡无法打通，但是容器和网卡之间可以打通。


■ 不同网段(卡) 上的容器互相 ping 通

  • 通过 network connect
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat01 ping tomcat-net-01
\\PING tomcat-net-01 (192.168.0.2) 56(84) bytes of data.
64 bytes from tomcat-net-01.mynet (192.168.0.2): icmp_seq=1 ttl=64 time=0.115 ms
64 bytes from tomcat-net-01.mynet (192.168.0.2): icmp_seq=2 ttl=64 time=0.063 ms
64 bytes from tomcat-net-01.mynet (192.168.0.2): icmp_seq=3 ttl=64 time=0.062 ms
^C
--- tomcat-net-01 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.062/0.080/0.115/0.024 ms
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker exec -it tomcat-net-01 ping tomcat01
PING tomcat01 (192.168.0.4) 56(84) bytes of data.
64 bytes from tomcat01.mynet (192.168.0.4): icmp_seq=1 ttl=64 time=0.088 ms
64 bytes from tomcat01.mynet (192.168.0.4): icmp_seq=2 ttl=64 time=0.064 ms

6、结论：

想要跨网络操作别人，就需要使用docker network connect 连通!



五、实战部署Redis集群

1、集群，需要建立自己的网卡

2、分片+高可用+负载均衡

3、shell 脚本！ 来启动这6个容器


4、部署Redis集群过程如下：

# 准备工作，移除掉系统其他的容器，避免启动过多的容器导致系统奔溃
docker rm -f $(docker ps -a)
# 创建redis 网卡
docker network create redis --subnet 172.38.0.0/16
# 检查一下redis 网卡的信息
docker network ls
docker network inspect redis
  • shell脚本创建六个redis配置
# 通过脚本创建六个redis配置
for port in $(seq 1 6); \
do \
mkdir -p /mydata/redis/node-${port}/conf
touch /mydata/redis/node-${port}/conf/redis.conf
cat << EOF >/mydata/redis/node-${port}/conf/redis.conf
port 6379
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
cluster-announce-ip 172.38.0.1${port}
cluster-announce-port 6379
cluster-announce-bus-port 16379
appendonly yes
EOF
done
  • 查看一下结点：
[root@iZwz9535z41cmgcpkm7i81Z ~]# cd /mydata/redis/
[root@iZwz9535z41cmgcpkm7i81Z redis]# ls
node-1  node-2  node-3  node-4  node-5  node-6
  • 启动结点容器：
 docker run -p 637${port}:6379 -p 1637${port}:16379 --name redis-${port} \
 -v /mydata/redis/node-${port}/data:/data \
 -v /mydata/redis/node-${port}/conf/redis.conf:/etc/redis/redis.conf \
 -d --net redis --ip 172.38.0.1${port} redis:5.0.9-alpine3.11 redis-server /etc/redis/redis.conf
  • 一个一个启动的方式：
 docker run -p 6371:6379 -p 16371:16379 --name redis-1 \
 -v /mydata/redis/node-1/data:/data \
 -v /mydata/redis/node-1/conf/redis.conf:/etc/redis/redis.conf \
 -d --net redis --ip 172.38.0.11 redis:5.0.9-alpine3.11 redis-server /etc/redis/redis.conf 
 
 
  docker run -p 6372:6379 -p 16372:16379 --name redis-2 \
 -v /mydata/redis/node-2/data:/data \
 -v /mydata/redis/node-2/conf/redis.conf:/etc/redis/redis.conf \
 -d --net redis --ip 172.38.0.12 redis:5.0.9-alpine3.11 redis-server /etc/redis/redis.conf 
 
 
 docker run -p 6373:6379 -p 16373:16379 --name redis-3 \
 -v /mydata/redis/node-3/data:/data \
 -v /mydata/redis/node-3/conf/redis.conf:/etc/redis/redis.conf \
 -d --net redis --ip 172.38.0.13 redis:5.0.9-alpine3.11 redis-server /etc/redis/redis.conf 
 
 
 docker run -p 6374:6379 -p 16374:16379 --name redis-4 \
 -v /mydata/redis/node-4/data:/data \
 -v /mydata/redis/node-4/conf/redis.conf:/etc/redis/redis.conf \
 -d --net redis --ip 172.38.0.14 redis:5.0.9-alpine3.11 redis-server /etc/redis/redis.conf 
 
 
 docker run -p 6375:6379 -p 16375:16379 --name redis-5 \
 -v /mydata/redis/node-5/data:/data \
 -v /mydata/redis/node-5/conf/redis.conf:/etc/redis/redis.conf \
 -d --net redis --ip 172.38.0.15 redis:5.0.9-alpine3.11 redis-server /etc/redis/redis.conf 
 
 
 docker run -p 6376:6379 -p 16376:16379 --name redis-6 \
 -v /mydata/redis/node-6/data:/data \
 -v /mydata/redis/node-6/conf/redis.conf:/etc/redis/redis.conf \
 -d --net redis --ip 172.38.0.16 redis:5.0.9-alpine3.11 redis-server /etc/redis/redis.conf
  • 集群：
docker exec -it redis-1 /bin/sh

redis-cli --cluster create 172.38.0.11:6379 172.38.0.12:6379 172.38.0.13:6379 172.38.0.14:6379 172.38.0.15:6379 172.38.0.
16:6379 --cluster-replicas 1
>>> Performing hash slots allocation on 6 nodes...
Master[0] -> Slots 0 - 5460
Master[1] -> Slots 5461 - 10922
Master[2] -> Slots 10923 - 16383
Adding replica 172.38.0.15:6379 to 172.38.0.11:6379
Adding replica 172.38.0.16:6379 to 172.38.0.12:6379
Adding replica 172.38.0.14:6379 to 172.38.0.13:6379
M: 0bd617e83421999d29fb55c25f798d3600495e76 172.38.0.11:6379
   slots:[0-5460] (5461 slots) master
M: 8b91a88e817dcff1a5f82d1ea577acf77799bd95 172.38.0.12:6379
   slots:[5461-10922] (5462 slots) master
M: d5baadcc8b4db9ae93f9c01ed2a204e7d84d0619 172.38.0.13:6379
   slots:[10923-16383] (5461 slots) master
S: 8806e059a5c76468aed86fddc1ec9f006c0de203 172.38.0.14:6379
   replicates d5baadcc8b4db9ae93f9c01ed2a204e7d84d0619
S: 155b2b1ef7443e87b944cd745c22584aa5660628 172.38.0.15:6379
   replicates 0bd617e83421999d29fb55c25f798d3600495e76
S: 33e7146e8084a4cb93b1d057612f6a46652e357f 172.38.0.16:6379
   replicates 8b91a88e817dcff1a5f82d1ea577acf77799bd95
Can I set the above configuration? (type 'yes' to accept): yes
>>> Nodes configuration updated
>>> Assign a different config epoch to each node
>>> Sending CLUSTER MEET messages to join the cluster
Waiting for the cluster to join
...
>>> Performing Cluster Check (using node 172.38.0.11:6379)
M: 0bd617e83421999d29fb55c25f798d3600495e76 172.38.0.11:6379
   slots:[0-5460] (5461 slots) master
   1 additional replica(s)
S: 8806e059a5c76468aed86fddc1ec9f006c0de203 172.38.0.14:6379
   slots: (0 slots) slave
   replicates d5baadcc8b4db9ae93f9c01ed2a204e7d84d0619
S: 33e7146e8084a4cb93b1d057612f6a46652e357f 172.38.0.16:6379
   slots: (0 slots) slave
   replicates 8b91a88e817dcff1a5f82d1ea577acf77799bd95
M: d5baadcc8b4db9ae93f9c01ed2a204e7d84d0619 172.38.0.13:6379
   slots:[10923-16383] (5461 slots) master
   1 additional replica(s)
S: 155b2b1ef7443e87b944cd745c22584aa5660628 172.38.0.15:6379
   slots: (0 slots) slave
   replicates 0bd617e83421999d29fb55c25f798d3600495e76
M: 8b91a88e817dcff1a5f82d1ea577acf77799bd95 172.38.0.12:6379
   slots:[5461-10922] (5462 slots) master
   1 additional replica(s)
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
  • 查询集群信息：
/data # redis-cli -c
127.0.0.1:6379> cluster info
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:6
cluster_my_epoch:1
cluster_stats_messages_ping_sent:315
cluster_stats_messages_pong_sent:323
cluster_stats_messages_sent:638
cluster_stats_messages_ping_received:318
cluster_stats_messages_pong_received:315
cluster_stats_messages_meet_received:5
cluster_stats_messages_received:638

127.0.0.1:6379> cluster nodes
8806e059a5c76468aed86fddc1ec9f006c0de203 172.38.0.14:6379@16379 slave d5baadcc8b4db9ae93f9c01ed2a204e7d84d0619 0 1651111739893 4 connected
33e7146e8084a4cb93b1d057612f6a46652e357f 172.38.0.16:6379@16379 slave 8b91a88e817dcff1a5f82d1ea577acf77799bd95 0 1651111741407 6 connected
d5baadcc8b4db9ae93f9c01ed2a204e7d84d0619 172.38.0.13:6379@16379 master - 0 1651111740000 3 connected 10923-16383
155b2b1ef7443e87b944cd745c22584aa5660628 172.38.0.15:6379@16379 slave 0bd617e83421999d29fb55c25f798d3600495e76 0 1651111740000 5 connected
8b91a88e817dcff1a5f82d1ea577acf77799bd95 172.38.0.12:6379@16379 master - 0 1651111740906 2 connected 5461-10922
0bd617e83421999d29fb55c25f798d3600495e76 172.38.0.11:6379@16379 myself,master - 0 165111739000 1 connected 0-5460
  • 测试设置key-value 键值对：
127.0.0.1:6379> set a b
-> Redirected to slot [15495] located at 172.38.0.13:6379
OK

  • 再开一个窗口，测试高可用性
    • stop掉当前集群中正在运行的redis-3，若是高可用架构搭建成功，则主机宕掉，从机会替代主机的
# 再开一个窗口，停止当前正在运行的容器redis-3
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker stop redis-3
redis-3
[root@iZwz9535z41cmgcpkm7i81Z ~]# docker ps
CONTAINER ID   IMAGE                    COMMAND                  CREATED             STATUS             PORTS                                              NAMES
5c15f03d7a55   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   About an hour ago   Up About an hour   0.0.0.0:6376->6379/tcp, 0.0.0.0:16376->16379/tcp   redis-6
f375fc1baaec   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   About an hour ago   Up About an hour   0.0.0.0:6375->6379/tcp, 0.0.0.0:16375->16379/tcp   redis-5
7e335e02b33d   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   About an hour ago   Up About an hour   0.0.0.0:6374->6379/tcp, 0.0.0.0:16374->16379/tcp   redis-4
4e721d20f8fd   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   About an hour ago   Up About an hour   0.0.0.0:6372->6379/tcp, 0.0.0.0:16372->16379/tcp   redis-2
e438501487a1   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   2 hours ago         Up 2 hours         0.0.0.0:6371->6379/tcp, 0.0.0.0:16371->16379/tcp   redis-1


# 测试在容器redis-3 被停止掉了，是否从机会替代上去
172.38.0.13:6379> get a
Could not connect to Redis at 172.38.0.13:6379: Host is unreachable
(32.33s)
not connected> 
/data # redis-cli -c
127.0.0.1:6379> get a
-> Redirected to slot [15495] located at 172.38.0.14:6379
"b"
172.38.0.14:6379>
  • 宕掉redis-3之后


  • 至此证明docker 搭建redis 集群完成！



☺ 参考来源：
狂神的B站视频《【狂神说Java】Docker最新超详细版教程通俗易懂》 https://www.bilibili.com/video/BV1og4y1q7M4



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posted @ 2022-05-19 09:48  一乐乐  阅读(126)  评论(0)  编辑  收藏  举报