s4 docker 网络2进阶

多容器复杂应用的部署

基于 flask容器，链接外部另一个redis 容器
docker pull redis
sudo docker run -d --name redis redis
# redis 没必要映射端口出来

创建flask镜像
docker build -t kvin/flask-redis .
              镜像名称   Dockerfile的路径  . 是当前目录
运行容器并连接到数据库
docker run -d --name flask-redis --link redis -e REDIS_HOST=redis kvin/flask-redis
docker exec -it flask-redis /bin/bash

FROM python:2.7
LABEL maintaner="Peng Xiao [email protected]"
COPY . /app
WORKDIR /app
RUN pip install flask redis
EXPOSE 5000
CMD [ "python", "app.py" ]

Dockerfile

app.py
from flask import Flask
from redis import Redis

import os
import socket

app = Flask(__name__)
redis = Redis(host=os.environ.get('REDIS_HOST', '127.0.0.1'), port=6379)
@app.route('/')

def hello():
    redis.incr('hits')
    return 'Hello Container World! I have been seen %s times and my hostname is %s.\n' % (redis.get('hits'),socket.gethostname())

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000, debug=True)

app.py

容器内部环境变量

root@1cd379675b76:/app# ping redis
PING redis (172.17.0.2) 56(84) bytes of data.
64 bytes from redis (172.17.0.2): icmp_seq=1 ttl=64 time=0.492 ms
64 bytes from redis (172.17.0.2): icmp_seq=2 ttl=64 time=0.134 ms
64 bytes from redis (172.17.0.2): icmp_seq=3 ttl=64 time=0.054 ms
64 bytes from redis (172.17.0.2): icmp_seq=4 ttl=64 time=0.134 ms
^C
--- redis ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
rtt min/avg/max/mdev = 0.054/0.203/0.492/0.170 ms

容器内部测试

没有映射时，宿主本地访问不了

[root@docker-node1 flask-redis]# curl 127.0.0.1:5000
curl: (7) Failed connect to 127.0.0.1:5000; Connection refused
[root@docker-node1 flask-redis]# docker run -d -p 5000:5000 --name flask-redis --link redis -e REDIS_HOST=redis kvin/flask-redis
28ea7f498f5b9084935aa0a4fa0332aa56701a4357346b215cae689842f41fb1
[root@docker-node1 flask-redis]# curl 127.0.0.1:5000
Hello Container World! I have been seen 8 times and my hostname is 28ea7f498f5b.
[root@docker-node1 flask-redis]# curl 127.0.0.1:5000
Hello Container World! I have been seen 9 times and my hostname is 28ea7f498f5b.
[root@docker-node1 flask-redis]# curl 127.0.0.1:5000
Hello Container World! I have been seen 10 times and my hostname is 28ea7f498f5b.
[root@docker-node1 flask-redis]# curl 127.0.0.1:5000
Hello Container World! I have been seen 11 times and my hostname is 28ea7f498f5b.

映射

sudo docker run -d --name test4 -e DK_NAME=lewen busybox /bin/sh -c "while true;do sleep 3600;done"
[root@docker-node1 flask-redis]# docker exec -it test4 /bin/sh
/ # env
HOSTNAME=e72d1e6b396a
SHLVL=1
HOME=/root
DK_NAME=lewen
TERM=xterm
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
PWD=/
/ #

启动容器时，提前给容器设置环境变量

多机器通信

overlay

What is VXLAN and how it works?

https://www.evoila.de/2015/11/06/what-is-vxlan-and-how-it-works/

https://coreos.com/eted/

安装 etcd

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-node1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&

在docker-node2上

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

检查cluster状态

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&

重启docker服务

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": {}
    }
]

创建overlay network

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

view

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"
}

view

创建连接demo网络的容器

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)
​

在docker-node1上

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

在docker-node2上

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:~$

验证连通性

[root@docker-node2 etcd-v3.0.12-linux-amd64]# docker run -d --name test1 --net demo busybox /bin/sh -c "while true;do sleep 3600;done"

到此位于不同机器上的docker容器通信完成

可以看到容器，分别有两个网卡 10.0.0.0/24 是基于demo网络的虚拟IP

172.xx.xx.xx 是分别宿主机基于 docker网桥的ip

查看网络中的容器