> 参考视频4-10
# Mutil-host networking with etcd
## setup etcd cluster
在docker-node1上
```
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docker-node2上
```
vagrant@docker-node2:~$ wget https://github.com/coreos/etcd/releases/download/v3.0.12/etcd-v3.0.12-linux-amd64.tar.gz
vagrant@docker-node2:~$ tar zxvf etcd-v3.0.12-linux-amd64.tar.gz
vagrant@docker-node2:~$ cd etcd-v3.0.12-linux-amd64/
vagrant@docker-node2:~$ nohup ./etcd --name docker-node2 --initial-advertise-peer-urls http://192.168.205.11:2380 \
--listen-peer-urls http://192.168.205.11:2380 \
--listen-client-urls http://192.168.205.11:2379,http://127.0.0.1:2379 \
--advertise-client-urls http://192.168.205.11:2379 \
--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&
```
检查cluster状态
```
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
```
## 重启docker服务
在docker-node1上
```
$ 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&
```
在docker-node2上
```
$ sudo service docker stop
$ sudo /usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --cluster-store=etcd://192.168.205.11:2379 --cluster-advertise=192.168.205.11:2375&
```
## 创建overlay network
在docker-node1上创建一个demo的overlay network
```
vagrant@docker-node1:~$ sudo docker network ls
NETWORK ID NAME DRIVER SCOPE
0e7bef3f143a bridge bridge local
a5c7daf62325 host host local
3198cae88ab4 none null local
vagrant@docker-node1:~$ sudo docker network create -d overlay demo
3d430f3338a2c3496e9edeccc880f0a7affa06522b4249497ef6c4cd6571eaa9
vagrant@docker-node1:~$ sudo docker network ls
NETWORK ID NAME DRIVER SCOPE
0e7bef3f143a bridge bridge local
3d430f3338a2 demo overlay global
a5c7daf62325 host host local
3198cae88ab4 none null local
vagrant@docker-node1:~$ sudo docker network inspect demo
[
{
"Name": "demo",
"Id": "3d430f3338a2c3496e9edeccc880f0a7affa06522b4249497ef6c4cd6571eaa9",
"Scope": "global",
"Driver": "overlay",
"EnableIPv6": false,
"IPAM": {
"Driver": "default",
"Options": {},
"Config": [
{
"Subnet": "10.0.0.0/24",
"Gateway": "10.0.0.1/24"
}
]
},
"Internal": false,
"Containers": {},
"Options": {},
"Labels": {}
}
]
```
我们会看到在node2上，这个demo的overlay network会被同步创建
```
vagrant@docker-node2:~$ sudo docker network ls
NETWORK ID NAME DRIVER SCOPE
c9947d4c3669 bridge bridge local
3d430f3338a2 demo overlay global
fa5168034de1 host host local
c2ca34abec2a none null local
```
通过查看etcd的key-value, 我们获取到，这个demo的network是通过etcd从node1同步到node2的
```
vagrant@docker-node2:~/etcd-v3.0.12-linux-amd64$ ./etcdctl ls /docker
/docker/network
/docker/nodes
vagrant@docker-node2:~/etcd-v3.0.12-linux-amd64$ ./etcdctl ls /docker/nodes
/docker/nodes/192.168.205.11:2375
/docker/nodes/192.168.205.10:2375
vagrant@docker-node2:~/etcd-v3.0.12-linux-amd64$ ./etcdctl ls /docker/network/v1.0/network
/docker/network/v1.0/network/3d430f3338a2c3496e9edeccc880f0a7affa06522b4249497ef6c4cd6571eaa9
vagrant@docker-node2:~/etcd-v3.0.12-linux-amd64$ ./etcdctl get /docker/network/v1.0/network/3d430f3338a2c3496e9edeccc880f0a7affa06522b4249497ef6c4cd6571eaa9 | jq .
{
"addrSpace": "GlobalDefault",
"enableIPv6": false,
"generic": {
"com.docker.network.enable_ipv6": false,
"com.docker.network.generic": {}
},
"id": "3d430f3338a2c3496e9edeccc880f0a7affa06522b4249497ef6c4cd6571eaa9",
"inDelete": false,
"ingress": false,
"internal": false,
"ipamOptions": {},
"ipamType": "default",
"ipamV4Config": "[{\"PreferredPool\":\"\",\"SubPool\":\"\",\"Gateway\":\"\",\"AuxAddresses\":null}]",
"ipamV4Info": "[{\"IPAMData\":\"{\\\"AddressSpace\\\":\\\"GlobalDefault\\\",\\\"Gateway\\\":\\\"10.0.0.1/24\\\",\\\"Pool\\\":\\\"10.0.0.0/24\\\"}\",\"PoolID\":\"GlobalDefault/10.0.0.0/24\"}]",
"labels": {},
"name": "demo",
"networkType": "overlay",
"persist": true,
"postIPv6": false,
"scope": "global"
}
```
## 创建连接demo网络的容器
在docker-node1上
```
vagrant@docker-node1:~$ sudo docker run -d --name test1 --net demo busybox sh -c "while true; do sleep 3600; done"
Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
56bec22e3559: Pull complete
Digest: sha256:29f5d56d12684887bdfa50dcd29fc31eea4aaf4ad3bec43daf19026a7ce69912
Status: Downloaded newer image for busybox:latest
a95a9466331dd9305f9f3c30e7330b5a41aae64afda78f038fc9e04900fcac54
vagrant@docker-node1:~$ sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a95a9466331d busybox "sh -c 'while true; d" 4 seconds ago Up 3 seconds test1
vagrant@docker-node1:~$ sudo docker exec test1 ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:0A:00:00:02
inet addr:10.0.0.2 Bcast:0.0.0.0 Mask:255.255.255.0
inet6 addr: fe80::42:aff:fe00:2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1450 Metric:1
RX packets:15 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1206 (1.1 KiB) TX bytes:648 (648.0 B)
eth1 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:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:648 (648.0 B) TX bytes:648 (648.0 B)
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:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
vagrant@docker-node1:~$
```
在docker-node2上
```
vagrant@docker-node2:~$ sudo docker run -d --name test1 --net demo busybox sh -c "while true; do sleep 3600; done"
Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
56bec22e3559: Pull complete
Digest: sha256:29f5d56d12684887bdfa50dcd29fc31eea4aaf4ad3bec43daf19026a7ce69912
Status: Downloaded newer image for busybox:latest
fad6dc6538a85d3dcc958e8ed7b1ec3810feee3e454c1d3f4e53ba25429b290b
docker: Error response from daemon: service endpoint with name test1 already exists.
vagrant@docker-node2:~$ sudo docker run -d --name test2 --net demo busybox sh -c "while true; do sleep 3600; done"
9d494a2f66a69e6b861961d0c6af2446265bec9b1d273d7e70d0e46eb2e98d20
```
验证连通性。
```
vagrant@docker-node2:~$ sudo docker exec -it test2 ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:0A:00:00:03
inet addr:10.0.0.3 Bcast:0.0.0.0 Mask:255.255.255.0
inet6 addr: fe80::42:aff:fe00:3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1450 Metric:1
RX packets:208 errors:0 dropped:0 overruns:0 frame:0
TX packets:201 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:20008 (19.5 KiB) TX bytes:19450 (18.9 KiB)
eth1 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:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:648 (648.0 B) TX bytes:648 (648.0 B)
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:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
vagrant@docker-node1:~$ sudo docker exec test1 sh -c "ping 10.0.0.3"
PING 10.0.0.3 (10.0.0.3): 56 data bytes
64 bytes from 10.0.0.3: seq=0 ttl=64 time=0.579 ms
64 bytes from 10.0.0.3: seq=1 ttl=64 time=0.411 ms
64 bytes from 10.0.0.3: seq=2 ttl=64 time=0.483 ms
^C
vagrant@docker-node1:~$
```
>
