云计算实训38——docker网络、跨主机容器之间的通讯

一、docker⽹络

1.桥接--bridge

所有容器连接到桥就可以使⽤外⽹，使⽤nat让容器可以访问外⽹

使⽤ ip a s指令查看桥，所有容器连接到此桥，ip地址都是 172.17.0.0/16 ⽹段，桥是启动docker服务后出现，在centos使⽤

bridge-utils安装

1.下载bridge-utilsyum -y install bridge-utils.x86_64 2.查看桥⽂件yum provides *bin/brctl3.查看桥brctl show4.使用network查看桥docker network ls

2.仅主机--host

与主机共享⽹络，可让容器连接外⽹所有容器与docker主机在同⼀个⽹络中，容器和外⽹相互访问创建⼀个新的容器[root@docker001 000]# docker run -d -p80 -v 查看ip，默认在桥上[root@docker001 000]# docker inspect a4b6|grep IPA/opt/:/usr/share/nginx/html/ centosnginx:v1 a4b6324a55e63a0966086a18519dd58fa26eaf91d0017d143d57f25312dfeb85容器仅仅有lo⽹卡，不能与外界链接，在⾼级应⽤中使⽤，lo⽹卡，⽆法链接外⽹查看ip，默认在桥上[root@docker001 000]# docker inspect a4b6|grep IPA            "SecondaryIPAddresses": null,            "IPAddress": "172.17.0.2",                    "IPAMConfig": null,                    "IPAddress": "172.17.0.2",绑定其他的桥[root@docker001 000]# docker run -d --network harbor_harbor centosnginx:v1 21a283fd5e684038d218892700e2b9689c0555bf2c59a554f00554bd0daca55d[root@docker001 000]# docker inspect 21a2|grep IPAdd            "SecondaryIPAddresses": null,            "IPAddress": "",                    "IPAddress": "172.19.0.11",\# 使⽤--network对⽹桥的选择绑定host主机⽹络[root@docker001 001]# docker run -it --network host yum:v0 /bin/bash[root@docker001 /]# yum -y install iprout\#内部查看ip是本地主机ip\# 外部查看ip 没有[root@docker001 001]# docker inspect 306d|grep IPAdd            "SecondaryIPAddresses": null,            "IPAddress": "",                    "IPAddress": "",主机名同真机，⽹络也同真机优点：可以直接访问容器缺点：端⼝占⽤，多容器同时运⾏⼀个服务，不建议，在测试环境中使⽤0

3.none

容器仅仅有lo⽹卡，不能与外界链接，在⾼级应⽤中使⽤，lo⽹卡，⽆法链接外⽹

二、跨主机容器之间通讯

1.工作原理

使用flannel为docker主机分配网段网段信息及ip信息保存在etcd数据库中flannel运行时，会从etcd数据库中读取配置docker的daemon文件，让docker0网卡和flannel的网段一致

2.flannel

overlay 覆盖型⽹络，不⽀持路由转发，通过数据etcd数据库保存⼦⽹信息以及⽹络分配信息

给每台主机分配⼀个⽹段，通过udp传输数据包

3.主控主机：node1

1.安装etcd#安装etcd数据库yum -y install etcd2.安装flannel#提供跨主机的容器网络通信yum -y install flannel3.修改etcd数据库配置
编辑配置文件vim /etc/etcd/etcd.conf #----------------------------------------------------------------
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379,http://0.0.0.0:4001"
#----------------------------------------------------------------#----------------------------------------------------------------------------
ETCD_ADVERTISE_CLIENT_URLS="http://192.168.1.34:2379,http://192.168.1.34:4001"
#----------------------------------------------------------------------------
4.启动etcd数据库
[root@node1 ~]# systemctl start etcd.service5.测试端口
[root@node1 ~]# netstat -lnput | grep 2379
tcp6       0      0 :::2379                 :::*                    LISTEN      1560/etcd           
[root@node1 ~]# netstat -lnput | grep 4001
tcp6       0      0 :::4001                 :::*                    LISTEN      1560/etcd  6.设置开机自启动
[root@node1 ~]# systemctl enable etcd.service 7.测试数据库的功能
#数据的存取#使用etcd数据库存入数据
[root@node1 ~]# etcdctl set testdir/testkey0 1000
1000
#使用etcd数据库取出数据
[root@node1 ~]# etcdctl get testdir/testkey0
1000[root@node1 ~]# etcdctl set b 123
123
[root@node1 ~]# 
[root@node1 ~]# etcdctl get b
1238.测试集群健康
[root@node1 ~]# etcdctl -C http://192.168.1.34:2379 cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://192.168.1.34:2379
cluster is healthy
[root@node1 ~]# etcdctl -C http://192.168.1.34:4001 cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://192.168.1.34:2379
cluster is healthy9.修改flannel配置文件[root@node1 ~]# vim /etc/sysconfig/flanneld #-----------------------------------------------
FLANNEL_ETCD_ENDPOINTS="http://192.168.1.34:2379"
#-----------------------------------------------10.向数据库中存⼊⽹段信息
[root@node1 ~]# etcdctl mk /atomic.io/network/config '{"Network":"172.20.0.0/16"}'
{"Network":"172.20.0.0/16"}[root@node1 ~]# etcdctl get /atomic.io/network/config
{"Network":"172.20.0.0/16"}
[root@node1 ~]# systemctl start flanneld.service 
[root@node1 ~]# systemctl enable flanneld.service 11.查看ip地址
[root@node1 ~]# ip a s12.安装docker[root@node1 ~]# rz -E
rz waiting to receive.
[root@node1 ~]# ls
anaconda-ks.cfg  docker.sh
[root@node1 ~]# source docker.sh 
[root@node1 ~]# systemctl start docker.service 13.docker服务没有开启之前查看ip
[root@node1 ~]# ifconfig14.启动docker服务后查看ip
[root@node1 ~]# systemctl start docker.service 
[root@node1 ~]# ifconfig
docker0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255ether 02:42:9c:98:9b:7c  txqueuelen 0  (Ethernet)RX packets 0  bytes 0 (0.0 B)RX errors 0  dropped 0  overruns 0  frame 0TX packets 0  bytes 0 (0.0 B)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
15.从其他主机复制一份daemon.json文件
[root@node1 ~]# scp root@192.168.1.32:/etc/docker/daemon.json /etc/docker/
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.1.32' (ECDSA) to the list of known hosts.
root@192.168.1.32's password: 
daemon.json                                 100%  329   126.4KB/s   00:00 
#重启docker
[root@node1 ~]# systemctl restart docker.service 
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.
此时出现启动不了的问题#修改配置文件
[root@node1 ~]# vim /usr/lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd16.查看flannel的子网ip
[root@node1 ~]# cat /run/flannel/subnet.env
FLANNEL_NETWORK=172.20.0.0/16
FLANNEL_SUBNET=172.20.76.1/24
FLANNEL_MTU=1472
FLANNEL_IPMASQ=false
FLANNEL_IPMASQ=false17.编辑daemon.json文件
[root@node1 ~]# vim /etc/docker/daemon.json 
{"registry-mirrors": ["https://do.nark.eu.org","https://dc.j8.work","https://docker.m.daocloud.io","https://dockerproxy.com","https://docker.mirrors.ustc.edu.cn","https://docker.nju.edu.cn"],"hosts":["tcp://0.0.0.0:2375","unix:///var/run/docker.sock"],"insecure-registries":["http://192.168.1.32:5000"],"bip" : "172.20.16.1/24","mtu" : 1472
}18.加载配置，重启docker
#重新加载daemon
[root@node1 ~]# systemctl daemon-reload 
#重启docker
[root@node1 ~]# systemctl restart docker.service 19.拉取镜像
[root@node1 ~]# docker pull centos
#创建容器
[root@node1 ~]# docker run -it centos:latest /bin/bash
[root@8848da0d2c68 /]# [root@node1 ~]# 
#查看容器详细信息
[root@node1 ~]# docker inspect 8848da0d2c68

4.被控主机：node2

1.安装flannel[root@node2 ~]# yum -y install flannel2.配置flannel
#配置flannel文件
[root@node2 ~]# vim /etc/sysconfig/flanneld# Flanneld configuration options  
# etcd url location.  Point this to the server where etcd runs
#------------------------------------------------
FLANNEL_ETCD_ENDPOINTS="http://192.168.1.34:2379"
#------------------------------------------------
#此处的ip为node1的ip
# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_PREFIX="/atomic.io/network"
# Any additional options that you want to pass
#FLANNEL_OPTIONS=""3.启动flannel[root@node2 ~]# systemctl start flanneld.service4.查看flannel分配的ip[root@node2 ~]# cat /run/flannel/subnet.env 
FLANNEL_NETWORK=172.20.0.0/16
FLANNEL_SUBNET=172.20.32.1/24
FLANNEL_MTU=1472
FLANNEL_IPMASQ=false5.安装docker#拖拽docker.sh脚本
[root@node2 ~]# rz -E
rz waiting to receive.
[root@node2 ~]# ls
anaconda-ks.cfg  docker.sh
#让docker.sh脚本生效
[root@node2 ~]# source docker.sh 
#启动docker
[root@node2 ~]# systemctl start docker.service 6.配置deamon#从node1上传daemon文件到node2
[root@node2 ~]# scp root@192.168.1.34:/etc/docker/daemon.json /etc/docker/
Are you sure you want to continue connecting (yes/no)? yes
root@192.168.1.34's password: 
daemon.json 100%  428   274.9KB/s   00:00   
#查看flannel分配的ip
[root@node2 ~]# cat /run/flannel/subnet.env
FLANNEL_NETWORK=172.20.0.0/16
FLANNEL_SUBNET=172.20.32.1/24
FLANNEL_MTU=1472
FLANNEL_IPMASQ=false
#修改daemon.json文件
[root@node2 ~]# vim /etc/docker/daemon.json 
{"registry-mirrors": ["https://do.nark.eu.org","https://dc.j8.work","https://docker.m.daocloud.io","https://dockerproxy.com","https://docker.mirrors.ustc.edu.cn","https://docker.nju.edu.cn"],"hosts":["tcp://0.0.0.0:2375","unix:///var/run/docker.sock"],#----------------------------------------"insecure-registries":["http://192.168.1.32:5000"],"bip" : "172.20.32.1/24","mtu" : 1472#----------------------------------------
}
#修改docker.service文件
[root@node2 ~]# vim /usr/lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd7.重启daemon#此时重启docker会出现以下错误，按步骤操作即可
[root@node2 ~]# systemctl restart docker.service 
Warning: docker.service changed on disk. Run 'systemctl daemon-reload' to reload units.
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.
#重新加载daemon
[root@node2 ~]# systemctl daemon-reload
#重新启动docker服务
[root@node2 ~]# systemctl restart docker.service 8.拉取centos镜像
[root@node2 ~]# docker pull centos
#创建容器
[root@node2 ~]# docker run -it centos:latest /bin/bash
[root@33d47b2e38ce /]#
#使用ctrl p+q 退出#查看容器的详细信息
[root@node2 ~]# docker inspect 33d
"Gateway": "172.20.32.1","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"IPAddress": "172.20.32.2","IPPrefixLen": 24,"IPv6Gateway": "","MacAddress": "02:42:ac:14:20:02",9.ping node1中容器的ip[root@node2 ~]# ping 172.20.76.1
PING 172.20.76.1 (172.20.76.1) 56(84) bytes of data.
64 bytes from 172.20.76.1: icmp_seq=1 ttl=62 time=1.14 ms
64 bytes from 172.20.76.1: icmp_seq=2 ttl=62 time=0.989 ms
64 bytes from 172.20.76.1: icmp_seq=3 ttl=62 time=0.833 ms
64 bytes from 172.20.76.1: icmp_seq=4 ttl=62 time=0.772 ms
^C
--- 172.20.76.1 ping statistics ---