docker网络
0、路由器
家庭局域网里：
192.168.0.1 0.1一般都是路由器ip
192.168.0.2 0.2或0.3是手机ip
这两个ip在同一个网段，都在192.168网段，可以互相ping。
1、服务器开机
ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.0.106 netmask 255.255.255.0 broadcast 192.168.0.255
inet6 fe80::2ecd:bc25:b2cf:8ef2 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:ac:e2:8f txqueuelen 1000 (Ethernet)
RX packets 114 bytes 13572 (13.2 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 115 bytes 15020 (14.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
2、开启docker守护进程
systemctl start docker
ifconfig
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255 docker0 ----> 172.17.0.1 ---->docker网关
ether 02:42:80:38:9f:d0 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.0.106 netmask 255.255.255.0 broadcast 192.168.0.255
inet6 fe80::2ecd:bc25:b2cf:8ef2 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:ac:e2:8f txqueuelen 1000 (Ethernet)
RX packets 210 bytes 21852 (21.3 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 174 bytes 22156 (21.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
3、启动一个容器
docker run -d tomcat:jdk8
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
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 00:0c:29:ac:e2:8f brd ff:ff:ff:ff:ff:ff
inet 192.168.0.106/24 brd 192.168.0.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet6 fe80::2ecd:bc25:b2cf:8ef2/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:69:7a:b3:0c 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::42:69ff:fe7a:b30c/64 scope link
valid_lft forever preferred_lft forever
9: veth3a9a596@if8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default
link/ether b2:05:0b:05:51:12 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet6 fe80::b005:bff:fe05:5112/64 scope link
valid_lft forever preferred_lft forever
每添加一个容器，宿主机多出一个容器网卡，比如 veth3a9a596@if8
4、容器内执行ip addr
docker exec -it 5ef7ccd3e8be 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
8: eth0@if9: <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
上面的情况用图片表示：
docker0是网关，每次生成一个新docker容器，docker0会使用veth-pair和新容器连接。容器和容器之间通信也要通过docker0作为中介。
因此容器 ping docker0，容器 ping 容器都没有问题。
docker exec -it 2f1ed7adf253 ping 172.17.0.1 --> OK
linux网卡和docker0是直接连接着的。
linux主机 ping docker0 172.17.0.1 --> ping 172.17.0.1 --> OK
linux主机 ping docker容器 172.17.0.2 --> ping 172.17.0.2 --> OK
docker容器 ping linux主机 --> docker exec -it 2f1ed7adf253 ping 192.168.0.106 --> OK
使用容器名称连接
上面都是通过ip连接的，这里使用容器name连接
1、--link
docker run -d --name tomcat01 tomcat:jdk8
docker run -d --name tomcat02 --link tomcat01 tomcat:jdk8
docker exec -it 5e94d5e0a99c ping tomcat01 // OK；5e94d5e0a99c 是tomcat02的id，这行的意思是tomcat01 ping tomcat02
查看tomcat02的hosts文件，--link做的事情就是修改了hosts文件
172.17.0.2 tomcat01 dda5e23bab7f
2、直接通过容器名称连接
使用自定义网络，我们一般不使用docker0
docker network --help
docker network create --help
docker network ls
docker network inspect fbfe37d6730e
docker network create --driver bridge --subnet 192.168.0.0/16 --gateway 192.168.0.1 mynet // 自定义网络
docker network ls // 查看docker网络
docker run -d --name tomcat01 --net mynet tomcat:jdk8 // 启动容器
docker run -d --name tomcat02 --net mynet tomcat:jdk8 // 启动容器
docker exec -it 8e1b496cd7c2 ping tomcat01 // 容器2 ping 容器1
网络连通
左右两边是不同的网段，不同的局域网，无法直接连接。
连接方法：
docker network connect mynet tomcat01
此命令把tomcat1加到了mynet路由器中，tomcat01这一个容器有了两个ip，公网ip私网ip。
