Docker——网络

2023-10-03 10:41:46

docker0

  1. 查看主机的ip

    [root@iZwz908j8pbqd86doyrez5Z test]# ip addr
#本机回环地址
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
#阿里云内网地址
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000  
    link/ether 00:16:3e:10:37:ba brd ff:ff:ff:ff:ff:ff
    inet 172.18.199.233/20 brd 172.18.207.255 scope global dynamic eth0
       valid_lft 309999819sec preferred_lft 309999819sec
#docker生成的地址
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default  
    link/ether 02:42:6f:43:1c:ae 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

  2. 查看容器的ip

    [root@iZwz908j8pbqd86doyrez5Z test]# docker exec -it 5046feaea51f ip addr
#容器内网地址
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
#docker生成的地址
282: eth0@if283: <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

  3. 尝试从主机直接ping通容器的eth0ip

    #尝试ping通主机和容器
[root@iZwz908j8pbqd86doyrez5Z test]# ping 172.17.0.2
#连接成功

  4. 容器间的通信:docker网络

    原理:使用了evth-pair技术,本质上都是通过主机相连.每个主机有一个端口对应一个容器(如上面的容器-282和主机-283),如此构成了一个局域网.实际上各个容器无法直接相连,只能通过enth0进行桥接

    #尝试ping通容器和容器
[root@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat1 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
284: eth0@if285: <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@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat2 ping 172.17.0.3
#测试:可以ping通

docker网络解决的问题:容器之间的ping通

原理

  1. 我们没启动一个docker容器,docker就会给docker容器分配一个ip，我们只要安装了docker,就会有一个网卡桥接模式,使用的技术是evth-pair技术

    #再次查看主机ip:多了一个263(猜测“283: veth30fdc0b@if282”表示:这里的263与容器内的262相对应,即每运行一个容器,都会创建一对网卡)
[root@iZwz908j8pbqd86doyrez5Z test]# 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
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:16:3e:10:37:ba brd ff:ff:ff:ff:ff:ff
    inet 172.18.199.233/20 brd 172.18.207.255 scope global dynamic eth0
       valid_lft 309996899sec preferred_lft 309996899sec
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:6f:43:1c:ae 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
283: veth30fdc0b@if282: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 4e:d2:72:ba:14:a0 brd ff:ff:ff:ff:ff:ff link-netnsid 0

  2. linux桥接:我们每启动一个容器,linux主机就会多一个虚拟网卡,这个网卡连接着各个容器,我们可以尝试使用两个容器进行通信

    #evth-pair技术:一对虚拟设备接口,他们都是成对出现的,一端连着协议,一端彼此相连
[root@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat1 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
284: eth0@if285: <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@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat2 ping 172.17.0.3

  3. 网络模型图

    Docker——网络

    结论:tomcat1和tomcat2公用一个路由器docker0

  4. 小结

    Docker——网络

    注:

    • Docker中的所有网络接口都是虚拟的.虚拟的转发效率高!
    • 只要容器删除,对应网桥一对就没了

  5. –link(官方不推荐)

    当通过datasource连接mysql时,通常总是对应一个指定的端口,而容器的端口却是在启动难时生成(主机端口-容器端口),是否有办法通过主机端口-服务找到对应的端口?

    #尝试直接ping通
docker exec -it tomcat2 ping tomcat1  #无法直接ping通

#尝试使用link启动一个容器
docker run -d -P --name tomcat3 --link tomcat2 tomcat
docker exec -it tomcat3 ping tomcat2  #可以ping通

#尝试tomcat1向tomcat2反向Ping通
docker exec -it tomcat1 ping tomcat3  #失败

#查看/etc/hosts文件探究--link原理
[root@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat3 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
172.17.0.4	tomcat2 e55b43eede71  #其实本质上是更改了hosts文件,将访问转到本地对应的端口
172.17.0.5	c13e595e3183

    原理:直接在/etc/hosts中写死了

  6. 自定义网络

    #查看当前的网络
[root@iZwz908j8pbqd86doyrez5Z ~]# docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
e33b6b9e8a86        bridge              bridge              local
e4a72501819c        host                host                local
ee755fa64360        none                null                local

    网络模式
    bridge:桥接模式,桥接docker(默认)
    none:不配置网络
    host:和宿主机共享网络
    container:容器内网络连通(不建议)

    测试

    # 我们直接启动的命令 --net bridge,也就是我们docker0的桥接
docker run -d -P --name tomcat01 tomcat
docker run -d -P --name tomcat01 --net bridge tomcat  #与上面等同

# docker0特点:默认,域名不能访问,可以--link打通,但是不推荐

#尝试建立一个自定义网络
#--driver bridge:桥接模式
#--subnet 192.168.0.0/16:子网地址(/16,说明只限制了前面16位,可以有255*255个不同的地址;如果是/24,则只有255个地址)
#--getaway 192.168.0.1:网关
[root@iZwz908j8pbqd86doyrez5Z ~]# docker network create --driver bridge --subnet 192.168.0.0/16 --gateway 192.168.0.1 mynet27ebc9223f194268120a12710971c9093c53b9fc3f65e19697ca63e05ee464f9
[root@iZwz908j8pbqd86doyrez5Z ~]# docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
e33b6b9e8a86        bridge              bridge              local
e4a72501819c        host                host                local
27ebc9223f19        mynet               bridge              local  #*
ee755fa64360        none                null                local

#docker network inspect mynet
[root@iZwz908j8pbqd86doyrez5Z ~]# docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "27ebc9223f194268120a12710971c9093c53b9fc3f65e19697ca63e05ee464f9",
        "Created": "2020-09-15T15:13:49.178777935+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",  #子网
                    "Gateway": "192.168.0.1"  #网关
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

#ping测试
[root@iZwz908j8pbqd86doyrez5Z ~]# docker run -d -P --net mynet --name tomcat4 tomcat
b763cb6ecf5d4befefcacac1c4fafff8bc3ef28de3ba51d11dfa36e64e0c7cbd
[root@iZwz908j8pbqd86doyrez5Z ~]# docker run -d -P --net mynet --name tomcat5 tomcat
f292f97cf1d6a0b7d6fc77f207730cf3774a65cf72bf99c3bb392e1acf6b4993
[root@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat4 ping tomcat5

#再次查看信息
[root@iZwz908j8pbqd86doyrez5Z ~]# docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "27ebc9223f194268120a12710971c9093c53b9fc3f65e19697ca63e05ee464f9",
        "Created": "2020-09-15T15:13:49.178777935+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": {  #两个容器
            "b763cb6ecf5d4befefcacac1c4fafff8bc3ef28de3ba51d11dfa36e64e0c7cbd": {
                "Name": "tomcat4",
                "EndpointID": "5f7cd9c91fdf08ff27ed82d0419aa428c365c1a2d1b5eed476bb1bdb45a86d06",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            },
            "f292f97cf1d6a0b7d6fc77f207730cf3774a65cf72bf99c3bb392e1acf6b4993": {
                "Name": "tomcat5",
                "EndpointID": "92660007315adb53a812b564b06090b3039a7771e7c5d9a4fad2b1c9df9753d8",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]

    注:

    • 不同的集群建立不同的网络
    • 我们自定义的网络docker都已经帮我们维护好了对应的关系,推荐我们平时这样使用网络!

  7. 网络连通

    #尝试ping通不同网段(bridge和mynet)的容器
[root@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat3 ping tomcat4
ping: tomcat4: Name or service not known

#在mynet网络中加入tomcat3容器
[root@iZwz908j8pbqd86doyrez5Z ~]# docker network connect mynet tomcat3
[root@iZwz908j8pbqd86doyrez5Z ~]# docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "27ebc9223f194268120a12710971c9093c53b9fc3f65e19697ca63e05ee464f9",
        "Created": "2020-09-15T15:13:49.178777935+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": {
            "b763cb6ecf5d4befefcacac1c4fafff8bc3ef28de3ba51d11dfa36e64e0c7cbd": {
                "Name": "tomcat4",
                "EndpointID": "5f7cd9c91fdf08ff27ed82d0419aa428c365c1a2d1b5eed476bb1bdb45a86d06",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            },
            "c13e595e31833afb032661b077f310bebce5d68bc19012caabc67dbaced129b9": {
                "Name": "tomcat3",
                "EndpointID": "ad22702408b9cad4cd67d58758506e60b6a48a0274f26a1134403c4153468a1f",
                "MacAddress": "02:42:c0:a8:00:04",
                "IPv4Address": "192.168.0.4/16",
                "IPv6Address": ""
            },
            "f292f97cf1d6a0b7d6fc77f207730cf3774a65cf72bf99c3bb392e1acf6b4993": {
                "Name": "tomcat5",
                "EndpointID": "92660007315adb53a812b564b06090b3039a7771e7c5d9a4fad2b1c9df9753d8",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]

#尝试用tomcat3来ping通tomcat4
[root@iZwz908j8pbqd86doyrez5Z ~]# docker exec -it tomcat3 ping tomcat4  #成功

    注:

    • 网段不同,无法ping通
    • 为了实现不同网段的容器互通,应该将要连通的容器连通整个网卡(图)
    • 连通之后,就是将容器加入到对应的网络中(一个容器,两个ip地址

  8. springboot打包docker镜像

    • 在IDEA中下载docker插件
    • 在IDEA中设置连接远程仓库
    • 编写dockerfile文件
    • 将jar和dockerfile文件发布上去
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