Docker容器学习与分享09

Docker容器之间的相互通信

先新建两个不同的网段，就用分享08里的两个网段作为新建的网段。

[root@promote ~]# docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
b6a32ec430e9        bridge              bridge              local
9ab80c94885b        host                host                local
0470e5b1d2ad        new2_net            bridge              local
236f3139821f        new_net             bridge              local
c42335728d98        none                null                local

接着查看一下这两个网段的具体信息。
先看一下new_net网段，网段是172.18.0.0/24。

[root@promote ~]# docker network inspect new_net
[
    {
        "Name": "new_net",
        "Id": "236f3139821f765d4d5572e81065645796bdb32675bdba41da706ca612625ae8",
        "Created": "2018-07-10T02:21:53.602649029-04:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

再查看一下new2_net网段,网段是192.168.1.0/24。

[root@promote ~]# docker network inspect new2_net
[
    {
        "Name": "new2_net",
        "Id": "0470e5b1d2ad2fca704d8788f652b76a777f05df37e3894dd8351e9989c5f3d9",
        "Created": "2018-07-10T02:24:01.201554097-04:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.1.0/24",
                    "Gateway": "192.168.1.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

接着创建两个容器，分别连接到new_net和new2_net两个不同的网段（使用Ctrl+P+Q让容器在后台运行）。

[root@promote ~]# docker run -it --name busybox --network new_net docker.io/busybox
/ # 
[root@promote ~]# docker run -it --name busybox2 --network new2_net docker.io/busybox
/ # 

创建完成之后，先进busybox查看一下网络设备，再ping一下busybox2看看容器的连通性。

[root@promote ~]# docker attach busybox
/ # ifconfig
eth0      Link encap:Ethernet  HWaddr 02:42:AC:12:00:02
        inet addr:172.18.0.2  Bcast:0.0.0.0  Mask:255.255.0.0
        inet6 addr: fe80::42:acff:fe12:2/64 Scope:Link
        UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
        RX packets:22 errors:0 dropped:0 overruns:0 frame:0
        TX packets:36 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:0
        RX bytes:1879 (1.8 KiB)  TX bytes:3108 (3.0 KiB)

lo        Link encap:Local Loopback
        inet addr:127.0.0.1  Mask:255.0.0.0
        inet6 addr: ::1/128 Scope:Host
        UP LOOPBACK RUNNING  MTU:65536  Metric:1
        RX packets:9 errors:0 dropped:0 overruns:0 frame:0
        TX packets:9 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:1000
        RX bytes:803 (803.0 B)  TX bytes:803 (803.0 B)          

[root@promote ~]# docker attach busybox
/ # ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2): 56 data bytes
^C
--- 192.168.1.2 ping statistics ---
19 packets transmitted, 0 packets received, 100% packet loss

发现ping不通，为了让它可以互相ping通，可以将busybox2连接到busybox所在的网络里。

[root@promote ~]# docker network connect new2_net busybox
[root@promote ~]#

再进入busyboxping一下busybox2试试。

[root@promote ~]# docker attach busybox
/ # ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2): 56 data bytes
64 bytes from 192.168.1.2: seq=0 ttl=64 time=0.094 ms
64 bytes from 192.168.1.2: seq=1 ttl=64 time=0.149 ms
64 bytes from 192.168.1.2: seq=2 ttl=64 time=0.139 ms
^C
--- 192.168.1.2 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 0.094/0.127/0.149 ms

发现可以ping通了。
再看一下busybox2的网络设备。

/ # ifconfig
eth0      Link encap:Ethernet  HWaddr 02:42:AC:12:00:02
        inet addr:172.18.0.2  Bcast:0.0.0.0  Mask:255.255.0.0
        inet6 addr: fe80::42:acff:fe12:2/64 Scope:Link
        UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
        RX packets:22 errors:0 dropped:0 overruns:0 frame:0
        TX packets:36 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:0
        RX bytes:1879 (1.8 KiB)  TX bytes:3108 (3.0 KiB)

eth1      Link encap:Ethernet  HWaddr 02:42:C0:A8:01:03
        inet addr:192.168.1.3  Bcast:0.0.0.0  Mask:255.255.255.0
        inet6 addr: fe80::42:c0ff:fea8:103/64 Scope:Link
        UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
        RX packets:13 errors:0 dropped:0 overruns:0 frame:0
        TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:0
        RX bytes:1026 (1.0 KiB)  TX bytes:1026 (1.0 KiB)

lo        Link encap:Local Loopback
        inet addr:127.0.0.1  Mask:255.0.0.0
        inet6 addr: ::1/128 Scope:Host
        UP LOOPBACK RUNNING  MTU:65536  Metric:1
        RX packets:9 errors:0 dropped:0 overruns:0 frame:0
        TX packets:9 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:1000
        RX bytes:803 (803.0 B)  TX bytes:803 (803.0 B)

发现busybox2容器多出一个网络设备eth1，就相当于为了可以让两个容器互通，在busybox2中添加了一块虚拟网卡，然后分配给它一个IP地址使得他们可以互通。