Title

docker网络

docker网络

查看docker0

docker如何处理网络


# 查看容器内部的网络地址 ip addr,容器启动时会得到docker分配的 eth0@if39,ip地址

[root@VM-4-6-centos /]# 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
38: eth0@if39: <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

# linux ping 容器内部,eth0@if39

[root@VM-4-6-centos /]# 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=0.043 ms
64 bytes from 172.17.0.2: icmp_seq=2 ttl=64 time=0.042 ms
64 bytes from 172.17.0.2: icmp_seq=3 ttl=64 time=0.041 ms
64 bytes from 172.17.0.2: icmp_seq=4 ttl=64 time=0.051 ms

每启动一个docker容器,docker就会给docker容器分配一个ip,只要安装了docker,就会有一个网卡docker0,桥接模式,使用的技术是 veth-pair

测试 ip addr,发现多了一个网卡

再启动一个容器,发现又多了一个网卡

进入新启动容器内部

发现这个容器的网卡,都是一对的 例如:38: eth0@if39
evth-pair 就是一对虚拟设备接口,是成对出现的,一段连着协议,一段连着彼此
有这个特性,veth-pair 充当一个桥梁,连接各种虚拟设备
OpenStac,docker容器之间的连接,OVS的连接,都是使用veth-pair技术


# 容器1与容器2 ping

[root@VM-4-6-centos /]# docker exec -it tomcat01 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=0.079 ms
64 bytes from 172.17.0.3: icmp_seq=2 ttl=64 time=0.057 ms
64 bytes from 172.17.0.3: icmp_seq=3 ttl=64 time=0.058 ms

容器与容器之间是可以 ping 通的
tomcat01与tomcat02通信,不是直接通信,是通过docker0进行转发
所有容器在不指定网络的情况下,都是docker0路由的,docker会给容器分配一个默认的可用ip


docker中所有的网络接口都是虚拟的,转发效率高
只要容器删除,对应网桥一对就没了

查看docker网络配置

[root@VM-4-6-centos /]# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
198357e49663   bridge    bridge    local   # 桥接网络
75b58b57cfa1   host      host      local
ed80f5867272   none      null      local

通过 docker network inspect 网络id 查看配置


link

编写了一个微服务,database url=ip:port,项目不重启,数据库ip换掉了,处理这个问题,使用名字访问容器


# 直接ping是无法ping通的

[root@VM-4-6-centos /]# docker exec -it tomcat02 ping tomcat01
ping: tomcat01: Name or service not known

# 解决 --link

[root@VM-4-6-centos /]# docker run -d -p 8082:8080 --name tomcat03 --link tomcat02 tomcat
1122bf60a5c18de3af234caebfa24e004acc853c5bf0449743db9358f6dceed1
[root@VM-4-6-centos /]# 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=0.104 ms
64 bytes from tomcat02 (172.17.0.3): icmp_seq=2 ttl=64 time=0.054 ms
64 bytes from tomcat02 (172.17.0.3): icmp_seq=3 ttl=64 time=0.051 ms

# 反向无法ping通

[root@VM-4-6-centos /]# docker exec -it tomcat02 ping tomcat03
ping: tomcat03: Name or service not known

# 查看 tomcat03 hosts文件

[root@VM-4-6-centos /]# 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 cf174a1b5a41
172.17.0.4      1122bf60a5c1

本质:--link 就是在hosts配置中增加了一个 172.17.0.3 tomcat02 cf174a1b5a41
不建议使用 --link,docker0问题:不支持容器名访问

自定义网络

查看所有的docker网络

网络模式

bridge:桥接模式(默认)

none:不配置网络

host:和宿主机共享网络

container:容器网络连通(使用少,局限大,不建议使用)

测试


# 直接启动命令 --net bridge,就是默认的docker0

docker run -d -p 8080:8080 --name tomcat01 tomcat
docker run -d -p 8080:8080 --net bridge --name tomcat01 tomcat

# docker0特点,默认域名不能访问,--link可以打通连接

# 自定义网络

# --driver bridge 桥接

# --subnet 192.168.0.0/16 子网 192.168.0.2~192.168.255.255

# --gateway 192.168.0.1 网关

docker network create --driver bridge --subnet 192.168.0.0/16 --gateway 192.168.0.1 mynet

[root@VM-4-6-centos /]# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
198357e49663   bridge    bridge    local
75b58b57cfa1   host      host      local
a08726f536e8   mynet     bridge    local
ed80f5867272   none      null      local

自己创建的网络


测试


# 在自定义网络下运行容器

[root@VM-4-6-centos /]# docker run -d -p 8080:8080 --name tomcat02-net --net mynet tomcat
5d5a05421388aa9c67264d27319db6287bb48c236887e9e886a8eaa612f672b3
[root@VM-4-6-centos /]# docker run -d -p 8081:8080 --name tomcat01-net --net mynet tomcat
407c6a46a07ce42a4619924d96b075dc93d43be952602876bbb4a59c9f5ce201
[root@VM-4-6-centos /]# docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "a08726f536e8dc278bfc7c7750e3ef61c0afb6922bcfc4847a5f905923260a52",
        "Created": "2021-09-06T17:15:46.250366164+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",
                    "Gateway": "192.168.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "407c6a46a07ce42a4619924d96b075dc93d43be952602876bbb4a59c9f5ce201": {
                "Name": "tomcat01-net",
                "EndpointID": "80b127167020d0be22f10e91681173bb8b1ac3297019757fa253743bb6b53aac",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",
                "IPv6Address": ""
            },
            "5d5a05421388aa9c67264d27319db6287bb48c236887e9e886a8eaa612f672b3": {
                "Name": "tomcat02-net",
                "EndpointID": "7569b8f529748201ea1826e1f9a17f67918c5343c888408da7c0d7819dc2184e",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]

# 测试ping连接

[root@VM-4-6-centos /]# docker exec -it tomcat01-net ping 192.168.0.2
PING 192.168.0.2 (192.168.0.2) 56(84) bytes of data.
64 bytes from 192.168.0.2: icmp_seq=1 ttl=64 time=0.082 ms
64 bytes from 192.168.0.2: icmp_seq=2 ttl=64 time=0.053 ms
64 bytes from 192.168.0.2: icmp_seq=3 ttl=64 time=0.055 ms
64 bytes from 192.168.0.2: icmp_seq=4 ttl=64 time=0.053 ms

# 现在不使用 --link 也可以访问

[root@VM-4-6-centos /]# docker exec -it tomcat02-net ping tomcat01-net
PING tomcat01-net (192.168.0.3) 56(84) bytes of data.
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=1 ttl=64 time=0.044 ms
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=2 ttl=64 time=0.045 ms
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=3 ttl=64 time=0.050 ms
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=4 ttl=64 time=0.053 ms
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=5 ttl=64 time=0.063 ms

自定义的网络docker都已经帮我们维护好了对应关系,推荐这样使用
好处:
  redis-不同的集群使用不同的网络,保证了集群是安全和健康
  mysql-不同的集群使用不同的网络,保证了集群是安全和健康

网络连通


测试 mynet网络与容器tomcat01打通

docker network connect mynet tomcat01

查看网络 mynet

docker network inspect mynet

一个容器两个ip

# tomcat01能够访问tomcat01-net

[root@VM-4-6-centos /]# docker exec -it tomcat01 ping tomcat01-net
PING tomcat01-net (192.168.0.3) 56(84) bytes of data.
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=1 ttl=64 time=0.063 ms
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=2 ttl=64 time=0.053 ms
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=3 ttl=64 time=0.053 ms
64 bytes from tomcat01-net.mynet (192.168.0.3): icmp_seq=4 ttl=64 time=0.052 ms

# tomcat02不能访问tomcat01-net

[root@VM-4-6-centos /]# docker exec -it tomcat02 ping tomcat01-net
ping: tomcat01-net: Name or service not known

需要跨网络操作别人,就需要用docker network connect 连通网络

部署redis集群


# 创建redis网卡

[root@VM-4-6-centos /]# docker network create redis --subnet 172.38.0.0/16

# 通过脚本创建六个redis配置,粘贴运行

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
bind 0.0.0.0
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

# 启动redis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; \

# 开启第一个

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

# 开启第二个

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

# 开启第三个

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

# 以此类推...

# 进入其中一个redis容器,由于redis镜像没有/bin/bash命令所以用/bin/sh命令

[root@VM-4-6-centos /]# docker exec -it redis-1 /bin/sh
/data # ls
appendonly.aof  nodes.conf

# 搭建集群

/data # 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

redis cli -c是集群 redis cli 是单机

查看节点

docker搭建redis集群完成

posted @ 2021-08-19 15:32  快乐小洋人  阅读(66)  评论(0)    收藏  举报