flannel集群安装

安装flannel网络组件

• 所有的node节点都需要安装网络插件才能让所有的Pod加入到同一个局域网中，本文是安装flannel网络插件的参考文档

• 建议直接使用yum安装flanneld，除非对版本有特殊需求，默认安装的是0.7.1版本的flannel

  yum install -y flannel

配置flannel

配置serivce文件,/usr/lib/systemd/system/flanneld.service

[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=${ETCD_ENDPOINTS} \
-etcd-prefix=${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

配置flannel-config文件,/etc/sysconfig/flanneld

# Flanneld configuration options
# etcd url location.  Point this to the server where etcd runs
ETCD_ENDPOINTS="https://10.1.70.61:2379,https://10.1.70.62:2379"
# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
ETCD_PREFIX="/kube-centos/network"
# Any additional options that you want to pass
FLANNEL_OPTIONS="-etcd-cafile=/etc/kubernetes/ssl/ca.pem -etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem -etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem"

flannel所有网络相关数据都存储在etcd中，需要与etcd交互，ETCD_ENDPOINTS填入集群地址，FLANNEL_OPTIONS填入访问etcd的TLS证书和公钥

创建网络配置

etcdctl --endpoints=https://10.1.70.61:2379,https://10.1.70.62:2379 \
  --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
etcdctl --endpoints=https://10.1.157.198:2379,https://10.2.70.6:2379 \
  --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":"vxlan"}}'