Docker 网络

2023-12-22 08:56:39

1. docker网络

宿主机可以 ping 通所有容器ip

安装完 docker ，查看就会发现有一个docker0 （桥接模式）

[root@localhost ~]# ip addr
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
    link/ether 02:42:ae:45:ef:24 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:aeff:fe45:ef24/64 scope link
       valid_lft forever preferred_lft forever

每启动一个容器，就会被分配一个ip

创建一个 tomcat01 容器

docker run -it -d --name tomcat01 tomcat

[root@localhost ~]# docker exec -it tomcat01 ip addr       进入容器查看发现被分配了一个ip
754: eth0@if755: <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

再创建一个 tomcat02 容器

[root@localhost ~]# docker run -it -d --name tomcat02 tomcat

[root@localhost ~]# docker exec -it tomcat02 ip addr
756: eth0@if757: <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@localhost ~]# ip addr
755: vethd4336f7@if754: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP
    link/ether 4e:7f:dd:63:87:d9 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::4c7f:ddff:fe63:87d9/64 scope link
       valid_lft forever preferred_lft forever
757: veth5f75a6f@if756: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP
    link/ether 1a:36:b2:db:db:47 brd ff:ff:ff:ff:ff:ff link-netnsid 1
    inet6 fe80::1836:b2ff:fedb:db47/64 scope link
       valid_lft forever preferred_lft forever

evth-pair 一对虚拟设备接口，充当桥梁（docker容器之间的连接）

容器间通过ip可以互相ping通（docker0 充当一个网桥）

docker中所有的网络接口都是虚拟的（容器删除，对应的网络接口就没了）

通过容器 ping ip可以通

[root@localhost ~]# docker exec -it tomcat01   ping 172.17.0.3

[root@localhost ~]# docker exec -it tomcat02 ping 172.17.0.2

2. --link

--link 就是在hosts配置文件中添加了映射，容器就通了（反向不通）

[root@localhost ~]# docker run -it -d -P --name tomcat01 tomcat
[root@localhost ~]# docker run -it -d -P --name tomcat02 --link tomcat01 tomcat

[root@localhost ~]# docker exec -it tomcat01 ping tomcat02      不通
ping: tomcat02: Name or service not known
[root@localhost ~]# docker exec -it tomcat02 ping tomcat01      可以ping通

[root@localhost ~]# docker exec -it tomcat02 cat /etc/hosts      发现有映射tomcat01的ip
172.17.0.2   tomcat01 65c57680f2bc
172.17.0.3   ee6aeed7803c

3. 自定义网络

bridge 桥接模式（默认）

none 不配置网络

host 和宿主机共享网络

container （用的少，局限大）容器网络联通

创建自定义网络

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

--driver bridge 桥接

--subnet 192.168. 0.0/16 子网地址

--gateway 192.168.0.1 网关

munet 自定义网络名

查看网络：

[root@localhost ~]# docker network inspect munet

"Name": "munet",
        "Id": "2ecbde298624b3646c698b3daa8c1d5167019a12061cf356e48934bb30aad4f3",
        "Created": "2021-07-21T10:57:41.448294416+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",
                    "Gateway": "192.168.0.1"

同一网络下的容器可以互相 ping通（网段一样）

[root@localhost ~]# docker run -it -d -P --name tomcat01 --net munet tomcat
[root@localhost ~]# docker run -it -d -P --name tomcat02 --net munet tomcat

[root@localhost ~]# docker network inspect munet

"Name": "tomcat01",
                "EndpointID": "0954a8b31bc98048905aca3ec22dbfa927b95ef9582cc5bac8eb760108bb1b17",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            },
            "4b9834461034300010f955014f437b0a2fa9774d370aabbbb29fa1a128c17cf0": {
                "Name": "tomcat02",
                "EndpointID": "76cf832ab775c27ac062059b82d5ed1eb114540e12e099819d66cf18f3ea6e7d",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",

都可以互相 ping 通

[root@localhost ~]# docker exec -it tomcat01 ping tomcat02
[root@localhost ~]# docker exec -it tomcat02 ping tomcat01
[root@localhost ~]# docker exec -it tomcat01 ping 192.168.0.3
[root@localhost ~]# docker exec -it tomcat02 ping 192.168.0.2

4. 容器和另一网络联通

网络munet

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

[root@localhost ~]# docker run -it -d -P --name tomcat01 --net munet tomcat

[root@localhost ~]# docker run -d -P --name tomcat-01 tomcat

容器tomcat-01 和网络 munet 联通

[root@localhost ~]# docker network connect munet   tomcat-01

可以ping通

[root@localhost ~]# docker exec -it tomcat-01 ping tomcat01

联通原理： tomcat-01 被分配了双ip

[root@localhost ~]# docker network inspect munet

"Name": "tomcat-01",
                "EndpointID": "c5716de80e55405454f36848390c34ec655e81d0d7fde500ee7f00a469816ba8",
                "MacAddress": "02:42:c0:a8:00:04",
                "IPv4Address": "192.168.0.4/16",
                "IPv6Address": ""

[root@localhost ~]# docker exec -it tomcat-01 ip addr
767: eth0@if768: <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

5. 案例：部署 redis 三主三从

创建网络：

docker network create redis --subnet 172.38.0.0/16
脚本写redis配置文件：

for port in $(seq 1 6); \

do \

mkdir -p /mydata/redis/node-${port}/conf

touch /mydata/redis/node-${port}/conf/redis.conf

cat /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
手动运行1-6个容器修改ip，端口和文件名

docker run -p 6371:6379 --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

解释：6379 redis的端口 -v 挂载配置文件

--net redis 自定义网络

--ip 172.38.0.11 容器ip

redis:5.0.9-alpine3.11 redis 版本

redis-server /etc/redis/redis.conf 通过conf文件启动

进入容器 docker exec -it redis-1 /bin/sh

创建cluster集群

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

进入redis集群 redis-cli -c

查看集群 cluster info

查看节点 cluster nodes

码农公寓

1. docker网络

2. --link

3. 自定义网络

4. 容器和另一网络联通

5. 案例：部署 redis 三主三从

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