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多个docker容器如何共享网络

作者admin，发布于 。

docker容器共享网络分为两种情况,一种是多个通过命令创建的容器共享,另一种是通过多个docker-compose创建的容器容器共享.一个docker-compose内部的容器本身网络就是共享的,这里就不用讨论了.

下面的例子以多个nginx共享网络为例,所用镜像为nginx:alpine.所有示例均没有映射端口和文件,仅此仅供学习共享网络.

一.创建共享网络

无论哪种方式,第一步都是创建一个共享网络,下面我们创建一个名为local_public的网络,网络名可以自定义.执行后会输出一个网络的ID,代表创建成功,我们也可以通过docker network ls来查看刚刚创建好的网络.

docker network create local_public

二.命令行启动容器共享网络

启动两个容器,容器名字可自定义,不重复即可

docker run --network=local_public -d --name nginx_1 nginx:alpine
docker run --network=local_public -d --name nginx_2 nginx:alpine

进入nginx_1容器,并尝试ping两个容器

docker exec -it nginx_1 sh
/ # ping nginx_1 -c 4
PING nginx_1 (172.20.0.2): 56 data bytes
64 bytes from 172.20.0.2: seq=0 ttl=64 time=0.171 ms
64 bytes from 172.20.0.2: seq=1 ttl=64 time=0.212 ms
64 bytes from 172.20.0.2: seq=2 ttl=64 time=0.207 ms
64 bytes from 172.20.0.2: seq=3 ttl=64 time=0.336 ms

--- nginx_1 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.171/0.231/0.336 ms
/ # ping nginx_2 -c 4
PING nginx_2 (172.20.0.3): 56 data bytes
64 bytes from 172.20.0.3: seq=0 ttl=64 time=0.273 ms
64 bytes from 172.20.0.3: seq=1 ttl=64 time=0.276 ms
64 bytes from 172.20.0.3: seq=2 ttl=64 time=0.353 ms
64 bytes from 172.20.0.3: seq=3 ttl=64 time=0.349 ms

--- nginx_2 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.273/0.312/0.353 ms

可以看到,是可以ping通nginx_1和nginx_2的,两个容器的IP不同.

进入nginx_2也可以得到同样的结果,这里不再赘述.

二.docker-compose启动容器共享网络

首先,避免在同一个文件夹下启动多个docker-compose编排的容器,因为这样首先要保证service名字不可重复,而且还需要同时启动,否则启动的时候会报一些警告,本文不深入讨论这个问题.

我的目录结构如下:

tree docker-test
docker-test
├── nginx1
│   └── 1.yml
└── nginx2
    └── 2.yml

1.yml文件内容如下:

version: "3"
services:
  nginx:
    image:
      nginx:alpine
    container_name: nginx1
    networks:
      - local_public #着重看这里
networks:
  local_public:
    external: true #着重看这里

2.yml文件内容如下:

version: "3"
services:
  nginx:
    image:
      nginx:alpine
    container_name: nginx2
    networks:
      - local_public
networks:
  local_public:
    external: true

分别启动两个容器:

docker-compose -f nginx1/1.yml up -d
docker-compose -f nginx2/2.yml up -d

进入nginx1容器,并尝试ping两个容器:

docker exec -it nginx1 sh
/ # ping nginx1 -c 4
PING nginx1 (172.20.0.2): 56 data bytes
64 bytes from 172.20.0.2: seq=0 ttl=64 time=0.238 ms
64 bytes from 172.20.0.2: seq=1 ttl=64 time=0.196 ms
64 bytes from 172.20.0.2: seq=2 ttl=64 time=0.208 ms
64 bytes from 172.20.0.2: seq=3 ttl=64 time=0.268 ms

--- nginx1 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.196/0.227/0.268 ms
/ # ping nginx2 -c 4
PING nginx2 (172.20.0.3): 56 data bytes
64 bytes from 172.20.0.3: seq=0 ttl=64 time=0.394 ms
64 bytes from 172.20.0.3: seq=1 ttl=64 time=0.358 ms
64 bytes from 172.20.0.3: seq=2 ttl=64 time=0.365 ms
64 bytes from 172.20.0.3: seq=3 ttl=64 time=0.348 ms

--- nginx2 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.348/0.366/0.394 ms

可以看到,是可以ping通nginx1和nginx2的,两个容器的IP不同.

进入nginx2也可以得到同样的结果,这里不再赘述.