k8s 核心网络插件flannel的安装2020-11-23_k8s网络组件flannel下载

flanneld安装部署
最主要的是让pod容器内部能互相联通，形成集群。
CNI 网络插件最主要的功能就是实现pod资源跨宿主机进行通讯
CNI 网络插件
flannel
calico
canal
contiv
OpenContrail
Kube-router
下载flannel: https://github.com/flannel/releases
在jackie21上部署
#cd /opt/src

#wget https:github.com/coreos/flannel/releases/download/v0.11.0/flannel-v0.11.0-linux-amd64.tar.gz

#mkdir /opt/flannel-v0.11.0

#tar xf flannel-v0.11.0-linux-amd-64.tar.gz -C /opt/flannel-v0.11.0/

#ln -s /opt/flannel-v0.11.0/ /opt/flannel

#cd flannel

#mkdir cert

#cd cert/

因为要和apserver通信，所以要配置client证书
cert]# scp jackie200:/opt/certs/ca.pem .
cert]# scp jackie200:/opt/certs/client.pem .
cert]# scp jackie200:/opt/certs/client-key.pem .

编辑环境变量env文件:
flannel ]#
vi /opt/flannel/subnet.env

FLANNEL_NETWORK=172.7.0.0/16
FLANNEL_SUBNET=172.7.21.1/24
FLANNEL_MTU=1500
FLANNEL_IPMASQ=false
1
2
3
4

创建启动脚本
jackie21上
vi /opt/flannel/flannel.sh

#!/bin/sh
./flanneld \
  --public-ip=10.0.0.21 \
  --etcd-endpoints=https://10.0.0.12:2379,https://10.0.0.21:2379,https://10.0.0.22:2379 \
  --etcd-keyfile=./cert/client-key.pem \
  --etcd-certfile=./cert/client.pem \
  --etcd-cafile=./cert/ca.pem \
  --iface=eth0 \
  --subnet-file=./subnet.env \
  --healthz-port=2401
1
2
3
4
5
6
7
8
9
10

chmod u+x flanneld.sh

创建日志存放目录
mkdir -p /data/logs/flanneld

在etcd中增加网络配置信息
cd /opt/etcd

测试使用host-gw模型:
#./etcdctl set /coreos.com/network/config ‘{“Network”: “172.7.0.0/16”, “Backend”: {“Type”: “host-gw”}}’

查看网络模型配置:
#./etcdctl get /coreos.com/network/config

编辑supervisor启动脚本:
vi /etc/supervisord.d/flannel.ini

[program:flanneld-7-21]
command=/opt/flannel/flanneld.sh                             ; the program (relative uses PATH, can take args)
numprocs=1                                                   ; number of processes copies to start (def 1)
directory=/opt/flannel                                       ; directory to cwd to before exec (def no cwd)
autostart=true                                               ; start at supervisord start (default: true)
autorestart=true                                             ; retstart at unexpected quit (default: true)
startsecs=30                                                 ; number of secs prog must stay running (def. 1)
startretries=3                                               ; max # of serial start failures (default 3)
exitcodes=0,2                                                ; 'expected' exit codes for process (default 0,2)
stopsignal=QUIT                                              ; signal used to kill process (default TERM)
stopwaitsecs=10                                              ; max num secs to wait b4 SIGKILL (default 10)
user=root                                                    ; setuid to this UNIX account to run the program
redirect_stderr=true                                         ; redirect proc stderr to stdout (default false)
stdout_logfile=/data/logs/flanneld/flanneld.stdout.log       ; stderr log path, NONE for none; default AUTO
stdout_logfile_maxbytes=64MB                                 ; max # logfile bytes b4 rotation (default 50MB)
stdout_logfile_backups=4                                     ; # of stdout logfile backups (default 10)
stdout_capture_maxbytes=1MB                                  ; number of bytes in 'capturemode' (default 0)
stdout_events_enabled=false                                  ; emit events on stdout writes (default false)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

更新supervisor配置:
supervisorctl update

这里需要修改iptables优化SNAT规则，否则在访问时，其他节点记录的是node节点的ip 10.4.7.21，而不是pod集群内部的172.7.21.x，红色部分按需修改

#yum install iptables-services -y

#iptables -t nat -D POSTROUTING -s 172.7.21.0/24 ! -o docker0 -j MASQUERADE

#iptables -t nat -I POSTROUTING -s 172.7.21.0/24 ! -d 172.7.0.0/16 ! -o docker0 -j MASQUERADE

#iptables-save |grep -i postrouting

#iptables-save > /etc/sysconfig/iptables
修改后会影响到docker原本的iptables链的规则，所以需要重启docker服务

#systemctl restart docker

配置vxlan模型：

cd /opt/etcd
./etcdctl set /coreos.com/network/config ‘{“Network”: “172.7.0.0/16”, “Backend”: {“Type”: “vxlan”}}’

重启flanneld：
#supervisorctl restart flanneld-7-21

可以发现多了一块网卡，这块网卡就是vxlan用于隧道通信的虚拟网卡：


配置vxlan跟host-gw混合模型：

./etcdctl set /coreos.com/network/config ‘{“Network”: “172.7.0.0/16”, “Backend”: {“Type”: “vxlan”,“Directrouting”: true}}’

重启flanneld：
#supervisorctl restart flanneld-7-21