Docker容器互联

docker network create -d bridge test-net

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

$ docker network create -d bridge test-net
>>>
598cb6250de10af201237d18f02ed0c2bb16726b8a354d6a8403c2e4e89677c4

$ docker network ls 
>>>
NETWORK ID          NAME                DRIVER              SCOPE
4d8c64f6d1ba        bridge              bridge              local
b7ac05c0789e        host                host                local
d236850078af        none                null                local
598cb6250de1        test-net            bridge              local

开启两个Ubuntu容器：

$ docker run -itd --name test-2 ubuntu:v1 /bin/bash
>>>
4fa527e28fb50cdb8067cc6498ce8c2c4462f7d24c589180f1587149528ead0e

$ docker run -itd --name test-1 ubuntu:v1 /bin/bash
>>>
03696463fad0a8c2130ecf0a60324a0309f94dc61b6038ba737b3c6de35963ad

测试容器test-1 和容器 test-2直接网络是否联通：

$ docker ps
>>>
ConTAINER ID   IMAGE       COMMAND       CREATED          STATUS          PORTS     NAMES
03696463fad0   ubuntu:v1   "/bin/bash"   54 seconds ago   Up 53 seconds             test-1
4fa527e28fb5   ubuntu:v1   "/bin/bash"   57 seconds ago   Up 56 seconds             test-2

$ docker exec -it test-1 /bin/bash
root@03696463fad0:/ ping test-2
>>>
ping: test-2: Name or service not known

test-1和test-2目前没有网络连接。

将两个容器加入网络:

docker network connect NETWORKID CONTAINER_ID

$ docker ps
>>>
ConTAINER ID   IMAGE       COMMAND       CREATED         STATUS         PORTS     NAMES
03696463fad0   ubuntu:v1   "/bin/bash"   3 minutes ago   Up 3 minutes             test-1
4fa527e28fb5   ubuntu:v1   "/bin/bash"   3 minutes ago   Up 3 minutes             test-2

$ docker network ls
>>>
NETWORK ID     NAME       DRIVER    SCOPE
5ec41a2e74f5   test-net   bridge    local
# 将容器test-1  test-2加入网络
$ docker network connect 5ec41a2e74f5 03696463fad0
$ docker network connect 5ec41a2e74f5 4fa527e28fb5
# 进入容器test-1并ping test-2
$ docker exec -it test-1 /bin/bash
root@03696463fad0:/ ping test-2
>>>
PING test-2 (172.18.0.3) 56(84) bytes of data.
64 bytes from test-2.test-net (172.18.0.3): icmp_seq=1 ttl=64 time=0.091 ms
64 bytes from test-2.test-net (172.18.0.3): icmp_seq=2 ttl=64 time=0.069 ms
64 bytes from test-2.test-net (172.18.0.3): icmp_seq=3 ttl=64 time=0.074 ms

在容器test-1里面可以ping通test-2，证明两个容器现在处于同一网络之中。

修改宿主机(docker安装的那台机器)的/etc/docker/daemon.json文件，在文件中加入：

{"dns":[114.114.114.114,
       8.8.8.8]}

配置后重启docker，再启动的所有容器的DNS会自动配置为114.114.114.114和8.8.8.8。

查看容器的dns是否修改成功：

$ docker run -it --rm ubuntu cat etc/resolv.conf

–rm的含义是退出容器后自动清理容器内部的文件结构。

在容器启动的命令中加入DNS信息：

$ docker run -it --rm -h=host_test --dns=114.114.114.114 --dns-search=test.com ubuntu

-h HOST_NAME或者–h=HOST_NAME 指定容器的host名称

–dns: 添加DNS服务器到容器的/etc/resolv.conf中，让容器用这个服务器来解析所有不在/etc/hosts中的主机名

–dns-search：设定容器的搜索域，当搜索域是test.con时，搜索一个名为host的主机时，DNS不仅搜索host，也会搜索 host.test.com

在启动容器时如果没有指定 --dns --dns-search，容器启动时会使用宿主机/etc/resolv.conf里面的配置来配置容器的DNS。