Kubernetes (K8s) 安装部署过程(六)之安装flannel网络插件
1、下载flannel包并安装
[root@k8s_Master package]# wget https://github.com/coreos/flannel/releases/download/v0.12.0/flannel-v0.12.0-linux-amd64.tar.gz
[root@k8s_Master package]# tar -xf flannel-v0.12.0-linux-amd64.tar.gz
[root@k8s_Master package]# cp flanneld /usr/local/bin/
[root@k8s_Master package]# cp mk-docker-opts.sh /usr/local/bin/
2、创建subnet.env文件
[root@k8s_Master package]# mkdir /etc/flannel
[root@k8s_Master package]# cd /etc/flannel/
[root@k8s_Master flannel]# vim subnet.env文件内容如下
FLANNEL_NETWORK=172.7.0.0/16
FLANNEL_SUBNET=172.7.21.1/24 #每个nodes的子网不一样需修改，test-nodes1为21，而test-nodes2为22
FLANNEL_MTU=1500
FLANNEL_IPMASQ=false3、编写启动服务，修改service文件/usr/lib/systemd/system/flanneld.service其内容为：
[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=network-online.target
Wants=network-online.target
After=etcd.service
Before=docker.service
[Service]
Type=notify
ExecStart=/usr/local/bin/flanneld \
--public-ip=192.168.0.221 \
--etcd-endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
--etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem \
--etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem \
--etcd-cafile=/etc/kubernetes/ssl/ca.pem \
--iface=ens33 \
--subnet-file=/etc/flannel/subnet.env \
--healthz-port=2401 \
--etcd-prefix=/kube-centos/network
ExecStartPost=/usr/local/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /etc/flannel/subnet.env
Restart=always
RestartSec=5
StartLimitInterval=0
[Install]
WantedBy=multi-user.target
RequiredBy=docker.service 4、在etcd中常见网络配置信息（#上下是2条命令，在任何节点上创建都行，因为etcd是集群的。如果你要使用vxlan模式，可以直接将host-gw改成vxlan即可。）
/usr/local/bin/etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
--ca-file=/etc/kubernetes/ssl/ca.pem \
--cert-file=/etc/kubernetes/ssl/kubernetes.pem \
--key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
mkdir /kube-centos/network[root@k8s_Master flannel]# etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
> --ca-file=/etc/kubernetes/ssl/ca.pem \
> --cert-file=/etc/kubernetes/ssl/kubernetes.pem \
> --key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
> mk /kube-centos/network/config '{"Network":"172.7.0.0/16","SubnetLen":24,"Backend":{"Type":"host-gw"}}' &
[1] 90008
[root@k8s_Master flannel]# {"Network":"172.7.0.0/16","SubnetLen":24,"Backend":{"Type":"host-gw"}}
[1]+ Done etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 --ca-file=/etc/kubernetes/ssl/ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem mk /kube-centos/network/config '{"Network":"172.7.0.0/16","SubnetLen":24,"Backend":{"Type":"host-gw"}}'
5、设置开机启动
# systemctl enable flanneld
# systemctl start flanneld
# systemctl status flanneld具体信息如下
[root@k8s_Master flannel]# systemctl daemon-reload
[root@k8s_Master flannel]# systemctl enable flanneld
Created symlink /etc/systemd/system/multi-user.target.wants/flanneld.service → /usr/lib/systemd/system/flanneld.service.
Created symlink /etc/systemd/system/docker.service.requires/flanneld.service → /usr/lib/systemd/system/flanneld.service.
[root@k8s_Master flannel]# systemctl stop flanneld
\[root@k8s_Master flannel]# systemctl start flanneld
[root@k8s_Master flannel]# systemctl status flanneld
● flanneld.service - Flanneld overlay address etcd agent
Loaded: loaded (/usr/lib/systemd/system/flanneld.service; enabled; vendor preset: disabled)
Active: active (running) since Sat 2020-08-22 03:02:00 CST; 6s ago
Process: 90114 ExecStartPost=/usr/local/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /etc/flannel/subnet.env (code=exited, status=0/SUCCESS)
Main PID: 90103 (flanneld)
Tasks: 13 (limit: 17489)
Memory: 10.8M
CGroup: /system.slice/flanneld.service
└─90103 /usr/local/bin/flanneld --public-ip=192.168.0.221 --etcd-endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 --etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem --etcd-certfile=/etc/kubernetes/ssl/kubernetes.p>
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.116408 90103 main.go:321] Wrote subnet file to /etc/flannel/subnet.env
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.116435 90103 main.go:325] Running backend.
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.119497 90103 route_network.go:53] Watching for new subnet leases
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.356024 90103 main.go:433] Waiting for 22h59m40.973126967s to renew lease
Aug 22 03:02:00 k8s_Master systemd[1]: Started Flanneld overlay address etcd agent.
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.833622 90103 iptables.go:145] Some iptables rules are missing; deleting and recreating rules
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.833650 90103 iptables.go:167] Deleting iptables rule: -s 172.7.0.0/16 -j ACCEPT
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.840175 90103 iptables.go:167] Deleting iptables rule: -d 172.7.0.0/16 -j ACCEPT
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.841626 90103 iptables.go:155] Adding iptables rule: -s 172.7.0.0/16 -j ACCEPT
Aug 22 03:02:00 k8s_Master flanneld[90103]: I0822 03:02:00.857381 90103 iptables.go:155] Adding iptables rule: -d 172.7.0.0/16 -j ACCEPT6、在其它的两台机器上也要执行相应的操作
（1）传包
[root@k8s_Master flannel]# scp flanneld mk-docker-opts.sh 192.168.0.222:/usr/local/bin/
[email protected]'s password:
flanneld 100% 34MB 269.0MB/s 00:00
mk-docker-opts.sh 100% 2139 2.6MB/s 00:00
[root@k8s_Master flannel]# scp flanneld mk-docker-opts.sh 192.168.0.223:/usr/local/bin/
[email protected]'s password:
flanneld 100% 34MB 179.7MB/s 00:00
mk-docker-opts.sh 100% 2139 2.7MB/s 00:00（2）传输环境配置文件
[root@k8s_Node1 ~]# mkdir /etc/flannel/[root@k8s_Master flannel]# scp /etc/flannel/subnet.env 192.168.0.222:/etc/flannel/
[email protected]'s password:
subnet.env 100% 26 13.1KB/s 00:00
[root@k8s_Master flannel]# scp /etc/flannel/subnet.env 192.168.0.223:/etc/flannel/
[email protected]'s password:
subnet.env 100% 26 19.3KB/s 00:00（3）传输启动文件（记得将public-ip的值改成相应节点的IP地址）
[root@k8s_Master flannel]# scp /usr/lib/systemd/system/flanneld.service 192.168.0.222:/usr/lib/systemd/system
[email protected]'s password:
flanneld.service 100% 856 141.1KB/s 00:00
[root@k8s_Master flannel]# scp /usr/lib/systemd/system/flanneld.service 192.168.0.223:/usr/lib/systemd/system
[email protected]'s password:
flanneld.service 100% 856 890.7KB/s 00:00 （4）在node节点上启动flanneld服务
# systemctl enable flanneld
# systemctl start flanneld
# systemctl status flanneld
现在查询etcd中的内容可以看到：
[root@k8s_Node1 ~]# /usr/local/bin/etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
> --ca-file=/etc/kubernetes/ssl/ca.pem \
> --cert-file=/etc/kubernetes/ssl/kubernetes.pem \
> --key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
> ls /kube-centos/network/subnets
/kube-centos/network/subnets/172.7.21.0-24
/kube-centos/network/subnets/172.7.28.0-24
/kube-centos/network/subnets/172.7.68.0-24
[root@k8s_Node1 ~]# /usr/local/bin/etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
--ca-file=/etc/kubernetes/ssl/ca.pem \
--cert-file=/etc/kubernetes/ssl/kubernetes.pem \
--key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
get /kube-centos/network/config
{"Network":"172.7.0.0/16","SubnetLen":24,"Backend":{"Type":"host-gw"}}
[root@k8s_Master flannel]# /usr/local/bin/etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
--ca-file=/etc/kubernetes/ssl/ca.pem \
--cert-file=/etc/kubernetes/ssl/kubernetes.pem \
--key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
get /kube-centos/network/subnets/172.7.21.0-24
{"PublicIP":"192.168.0.221","BackendType":"host-gw"}
[root@k8s_Node1 ~]# /usr/local/bin/etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
--ca-file=/etc/kubernetes/ssl/ca.pem \
--cert-file=/etc/kubernetes/ssl/kubernetes.pem \
--key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
get /kube-centos/network/subnets/172.7.28.0-24
{"PublicIP":"192.168.0.222","BackendType":"host-gw"}
[root@k8s_Node2 ~]# /usr/local/bin/etcdctl --endpoints=https://192.168.0.221:2379,https://192.168.0.222:2379,https://192.168.0.223:2379 \
--ca-file=/etc/kubernetes/ssl/ca.pem \
--cert-file=/etc/kubernetes/ssl/kubernetes.pem \
--key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
get /kube-centos/network/subnets/172.7.68.0-24
{"PublicIP":"192.168.0.223","BackendType":"host-gw"}