讓Docker容器使用靜態獨立的外部IP（便於集群組建）

 

需要使用Docker虛擬化Hadoop/Spark等測試環境，並且要可以對外提供服務，要求是完全分布式的部署（盡量模擬生產環境）。那么我們會遇到幾個問題：

1. Container IP 是動態分配的

2. Container IP 是內部IP，外部無法訪問（如對外提供HDFS服務可能會遇到Client無法訪問DataNode，因為DataNode注冊的是內部IP）

針對第一個問題有不少的方案，可以指定靜態的IP，對第二個問題，我們可以使用--net=host解決，但這會導致對外只有一個IP，集群各個Slave的端口都要修改。至於pipework簡單地看了下，好像也解決不了。

所以目前看上去只能使用看上去不是很優雅的方案解決:*為Docker宿主網卡綁定多個IP，把這些IP分配給不同的容器。

//這是示例，我是在windows下用Docker toolbox運行的
root@default:~# ifconfig docker0 Link encap:Ethernet HWaddr 02:42:8C:8E:80:F1 inet addr:172.17.42.1 Bcast:0.0.0.0 Mask:255.255.0.0 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) eth0 Link encap:Ethernet HWaddr 08:00:27:24:D1:F5 inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fe24:d1f5/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:222 errors:0 dropped:0 overruns:0 frame:0 TX packets:164 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:32277 (31.5 KiB) TX bytes:28136 (27.4 KiB) eth1 Link encap:Ethernet HWaddr 08:00:27:76:1D:9B inet addr:192.168.99.100 Bcast:192.168.99.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fe76:1d9b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:66 errors:0 dropped:0 overruns:0 frame:0 TX packets:64 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:9001 (8.7 KiB) TX bytes:10469 (10.2 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:16 errors:0 dropped:0 overruns:0 frame:0 TX packets:16 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1152 (1.1 KiB) TX bytes:1152 (1.1 KiB) //eth1網卡是可以與外部交互，所以我們添加IP到這個網卡上 //第一步：添加了兩個IP root@default:~# ifconfig eth1:0 192.168.99.10 netmask 255.255.255.0 up root@default:~# ifconfig eth1:1 192.168.99.11 netmask 255.255.255.0 up //再次查看，多了兩個IP root@default:~# ifconfig ... eth1 Link encap:Ethernet HWaddr 08:00:27:76:1D:9B inet addr:192.168.99.100 Bcast:192.168.99.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fe76:1d9b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:2258 errors:0 dropped:0 overruns:0 frame:0 TX packets:1685 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:207033 (202.1 KiB) TX bytes:209587 (204.6 KiB) eth1:0 Link encap:Ethernet HWaddr 08:00:27:76:1D:9B inet addr:192.168.99.10 Bcast:192.168.99.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 eth1:1 Link encap:Ethernet HWaddr 08:00:27:76:1D:9B inet addr:192.168.99.11 Bcast:192.168.99.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 ... //第二步：運行容器，指定IP，這里的示例容器開啟的SSH服務，后面拿它測試 root@default:~# docker run -d -p 192.168.99.10:222:22 --name ssh1 gudaoxuri/scala-2.11-env root@default:~# docker run -d -p 192.168.99.11:222:22 --name ssh2 gudaoxuri/scala-2.11-env root@default:~# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES ab024af9c954 gudaoxuri/scala-2.11-env "/usr/sbin/sshd -D" 4 seconds ago Up 3 seconds 192.168.99.11:222->22/tcp ssh2 259351134d16 gudaoxuri/scala-2.11-env "/usr/sbin/sshd -D" 15 seconds ago Up 14 seconds 192.168.99.10:222->22/tcp ssh1 //測試連接，在Docker宿主機上SSH到第一個容器 root@default:~# ssh 192.168.99.10 -p222 The authenticity of host '[192.168.99.10]:222 ([192.168.99.10]:222)' can't be established. RSA key fingerprint is ac:fe:4b:89:f8:51:b7:e9:9c:34:62:f9:80:38:4b:bf. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '[192.168.99.10]:222' (RSA) to the list of known hosts. root@192.168.99.10's password: Last login: Wed Oct 7 13:12:35 2015 from 192.168.99.1 //成功進入 [root@259351134d16 ~]# //在第一個容器中SSH到第二個容器 [root@259351134d16 ~]# ssh 192.168.99.11 -p222 root@192.168.99.11's password: Last login: Wed Oct 7 13:14:53 2015 from 172.17.42.1 //也OK了 [root@ab024af9c954 ~]#