我之前給大家介紹的都是在一臺服務器上面操作的甸鸟，顯然有時候我們需要兩臺甚至更多的服務器，那么這個時候容器之間還可以通信嘛趟脂？答案是肯定的泰讽，可以！那具體該怎么操作呢昔期？往下看已卸！
比如現(xiàn)在我們有兩臺linux服務器，一個是192.168.205.10镇眷，一個是192.168.205.11咬最，這兩臺服務器是網(wǎng)絡是互通的可以相互傳遞數(shù)據(jù)包。關(guān)于這里面更多的知識欠动，大家可以去搜索VXLAN永乌，相信你可以學的更多惑申。
在這里給大家介紹一個分布式存儲的工具etcd,這個可以讓我們不同容器之間的ip是不會相同的，即使是不同的服務器上面也不會相同翅雏。
我們進入第一臺服務器里面圈驼，安裝服務器的方式之前已經(jīng)講過這里就不過多的講解了不懂的可以留言。
vagrant@docker-node1:~$ wget https://github.com/coreos/etcd/releases/download/v3.0.12/etcd-v3.0.12-linux-amd64.tar.gz
vagrant@docker-node1:~$ tar zxvf etcd-v3.0.12-linux-amd64.tar.gz
vagrant@docker-node1:~$ cd etcd-v3.0.12-linux-amd64
vagrant@docker-node1:~$ nohup ./etcd --name docker-node1 --initial-advertise-peer-urls http://192.168.205.10:2380 \
--listen-peer-urls http://192.168.205.10:2380 \
--listen-client-urls http://192.168.205.10:2379,http://127.0.0.1:2379 \
--advertise-client-urls http://192.168.205.10:2379 \
--initial-cluster-token etcd-cluster \
--initial-cluster docker-node1=http://192.168.205.10:2380,docker-node2=http://192.168.205.11:2380 \
--initial-cluster-state new&
在你的第二臺服務器上面依然是這么進行操作的望几，安裝完成以后執(zhí)行
[vagrant@docker-node2 etcd-v3.0.12-linux-amd64]$ ./etcdctl cluster-health
member 21eca106efe4caee is healthy: got healthy result from http://192.168.205.10:2379
member 8614974c83d1cc6d is healthy: got healthy result from http://192.168.205.11:2379
cluster is healthy
[vagrant@docker-node1 etcd-v3.0.12-linux-amd64]$ ./etcdctl cluster-health
member 21eca106efe4caee is healthy: got healthy result from http://192.168.205.10:2379
member 8614974c83d1cc6d is healthy: got healthy result from http://192.168.205.11:2379
cluster is healthy
好的绩脆，兩臺服務器都搭建好了etcd分布式存儲，接下來重啟docker
sudo service docker stop
sudo /usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --cluster-store=etcd://192.168.205.10:2379 --cluster-advertise=192.168.205.10:2375&
記住橄抹，兩臺服務器上面的都是一樣的操作.
[vagrant@docker-node2 ~]$ sudo docker network ls
NETWORK ID NAME DRIVER SCOPE
51bb8a874f53 bridge bridge local
365d9aa40572 host host local
353efcf35ca9 none null local
[vagrant@docker-node1 ~]$ sudo docker network ls
NETWORK ID NAME DRIVER SCOPE
3fb456a2d940 bridge bridge local
e937e8bacd9e host host local
7de133b14f97 none null local
[vagrant@docker-node1 ~]$ sudo docker network create -d overlay demo
e37fd1fc050c19fd9e08bed8f2903c6e23559219f9214ca18d9c622d37805052
# 執(zhí)行完上面這條命令以后我們發(fā)現(xiàn)多了一個demo的網(wǎng)絡
[vagrant@docker-node1 ~]$ sudo docker network ls
NETWORK ID NAME DRIVER SCOPE
3fb456a2d940 bridge bridge local
e37fd1fc050c demo overlay global
e937e8bacd9e host host local
7de133b14f97 none null local
此時我們再次查看docker-node2的網(wǎng)絡情況發(fā)現(xiàn)靴迫。。楼誓。玉锌。
[vagrant@docker-node2 ~]$ sudo docker network ls
NETWORK ID NAME DRIVER SCOPE
51bb8a874f53 bridge bridge local
e37fd1fc050c demo overlay global
365d9aa40572 host host local
353efcf35ca9 none null local
這說明這兩邊是同步的，那么它是怎么做到的呢疟羹？這就是etcd起的作用主守。
接下來我們在兩臺服務器上面創(chuàng)建容器
[vagrant@docker-node1 ~]$ sudo docker run -d --name appleone --net demo busybox sh -c "while true; do sleep 3600; done"
Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
f70adabe43c0: Pull complete
Digest: sha256:58ac43b2cc92c687a32c8be6278e50a063579655fe3090125dcb2af0ff9e1a64
Status: Downloaded newer image for busybox:latest
2b6522b25ec88f72871776a823eee483d08ab644b4bfd40ebcd4dab2e6e4871e
[vagrant@docker-node2 etcd-v3.0.12-linux-amd64]$ sudo docker run -d --name appleone --net demo busybox sh -c "while true; do sleep 3600; done"
Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
f70adabe43c0: Pull complete
Digest: sha256:58ac43b2cc92c687a32c8be6278e50a063579655fe3090125dcb2af0ff9e1a64
Status: Downloaded newer image for busybox:latest
38397d5234b21799a2d9971fafa61efbc0275ed713d8d13bb033c931ae8d629d
docker: Error response from daemon: endpoint with name appleone already exists in network demo.
這個時候小伙伴們會發(fā)現(xiàn)如果我們想在第二臺服務器上面，創(chuàng)建一樣名字的容器就會報錯榄融，這個也是etcd起的作用参淫。
我們給它換個名字就OK了。
[vagrant@docker-node2 etcd-v3.0.12-linux-amd64]$ sudo docker run -d --name appletwo --net demo busybox sh -c "while true; do sleep 3600; done"
a85984fed576f9f0e37756e2a0db68c9026db835a20eb621fd939d041c646509
我們來查看一下兩個容器的ip地址
[vagrant@docker-node2 etcd-v3.0.12-linux-amd64]$ sudo docker exec appletwo ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1
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
7: eth0@if8: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1450 qdisc noqueue
link/ether 02:42:0a:00:00:03 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.3/24 brd 10.0.0.255 scope global eth0
valid_lft forever preferred_lft forever
10: eth1@if11: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
link/ether 02:42:ac:12:00:02 brd ff:ff:ff:ff:ff:ff
inet 172.18.0.2/16 brd 172.18.255.255 scope global eth1
valid_lft forever preferred_lft forever
[vagrant@docker-node1 ~]$ sudo docker exec appleone ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1
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
19: eth0@if20: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1450 qdisc noqueue
link/ether 02:42:0a:00:00:02 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.2/24 brd 10.0.0.255 scope global eth0
valid_lft forever preferred_lft forever
22: eth1@if23: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
link/ether 02:42:ac:12:00:02 brd ff:ff:ff:ff:ff:ff
inet 172.18.0.2/16 brd 172.18.255.255 scope global eth1
valid_lft forever preferred_lft forever
我們來ping一把
[vagrant@docker-node2 etcd-v3.0.12-linux-amd64]$ docker exec appletwo ping 10.0.0.2
PING 10.0.0.2 (10.0.0.2): 56 data bytes
64 bytes from 10.0.0.2: seq=0 ttl=64 time=2.435 ms
64 bytes from 10.0.0.2: seq=1 ttl=64 time=0.735 ms
我們發(fā)現(xiàn)兩個容器是可以ping通的
走到這里愧杯，我們基本已經(jīng)把docker的網(wǎng)絡知識都搞明白了涎才，從下節(jié)開始我們接觸新的知識，數(shù)據(jù)民效。小伙伴們一起加油把ｃ疚！Ｎ沸稀！检吆！Go! Go! Go!
