Kubernetes1.91（K8s）安装部署过程（五）--安装flannel网络插件

node节点需要安装flannel网络插件才能保证所有的pod在一个局域网内通信，直接使用yum安装即可，版本是0.7.1.

1、安装flannel插件：

注意是2个node节点都需要安装，都需要修改service文件和配置文件。

yum install  flannel -y

2、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
EnvironmentFile=/etc/sysconfig/flanneld
EnvironmentFile=-/etc/sysconfig/docker-network
ExecStart=/usr/bin/flanneld-start 
  -etcd-endpoints=${FLANNEL_ETCD_ENDPOINTS} 
  -etcd-prefix=${FLANNEL_ETCD_PREFIX} 
  $FLANNEL_OPTIONS
ExecStartPost=/usr/libexec/flannel/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker
Restart=on-failure

[Install]
WantedBy=multi-user.target
RequiredBy=docker.service

提示:service文件中所有的变量参数都是读取相应的配置文件里面的，所有要保证前后对应。

修改其配置文件/etc/sysconfig/flanneld 内容如下：

# Flanneld configuration options  

# etcd url location.  Point this to the server where etcd runs
FLANNEL_ETCD_ENDPOINTS="https://10.10.90.105:2379,https://10.10.90.106:2379,https://10.10.90.107:2379"

# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
#FLANNEL_ETCD_PREFIX="/atomic.io/network"
FLANNEL_ETCD_PREFIX="/kube-centos/network"

# Any additional options that you want to pass
#FLANNEL_OPTIONS=""
FLANNEL_OPTIONS="-etcd-cafile=/etc/kubernetes/ssl/ca.pem -etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem -etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem"

以上2步是2个node节点都需要做的。

3、在etcd中常见网络配置信息

etcdctl --endpoints=https://10.10.90.105:2379,https://10.10.90.106:2379,https://10.10.90.107:2379 
  --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

#上下是2条命令，在任何节点上创建都行，因为etcd是集群的。
etcdctl --endpoints=https://10.10.90.105:2379,https://10.10.90.106:2379,https://10.10.90.107:2379 
  --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":"172.30.0.0/16","SubnetLen":24,"Backend":{"Type":"host-gw"}}'

4、启动flannel服务

systemctl daemon-reload
systemctl enable flanneld
systemctl start flanneld
systemctl status flanneld

5、核对相关配置信息：

#先声明个endpoint变量，后边好调用
[root@c7test_node1 ~]#ETCD_ENDPOINTS='https://10.10.90.105:2379,https://10.10.90.106:2379,https://10.10.90.107:2379'

[root@c7test_node1 ~]# etcdctl --endpoints=${ETCD_ENDPOINTS} 
--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
#输出
/kube-centos/network/subnets/172.30.87.0-24
/kube-centos/network/subnets/172.30.92.0-24
#说明，有几个node就有几个子网络，就有几条记录，我是2个node，分别安装了flannel插件

 [root@c7test_node1 ~]# etcdctl --endpoints=${ETCD_ENDPOINTS}
 --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

 #输出
 {"Network":"172.30.0.0/16","SubnetLen":24,"Backend":{"Type":"host-gw"}}

 #此处是查看主网络配置

 etcdctl --endpoints=${ETCD_ENDPOINTS} --ca-file=/etc/kubernetes/ssl/ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernete   s/ssl/kubernetes-key.pem get /kube-centos/network/subnets/172.30.92.0-24

 #输出

{"PublicIP":"10.10.90.106","BackendType":"vxlan","BackendData":{"VtepMAC":"26:af:ac:26:47:ad"}}

 etcdctl --endpoints=${ETCD_ENDPOINTS} --ca-file=/etc/kubernetes/ssl/ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernete   s/ssl/kubernetes-key.pem get /kube-centos/network/subnets/172.30.87.0-24

 #输出

 {"PublicIP":"10.10.90.107","BackendType":"vxlan","BackendData":{"VtepMAC":"82:6f:58:94:9f:59"}}

如有以上输出即代表flannel插件安装配置成功，下一篇文章开始安装node节点。