## 安装flannel网络插件 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。 ```bash yum install -y flannel ``` service配置文件`/usr/lib/systemd/system/flanneld.service`。 ```ini [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 ``` `/etc/sysconfig/flanneld`配置文件： ```ini # Flanneld configuration options # etcd url location. Point this to the server where etcd runs FLANNEL_ETCD_ENDPOINTS="https://172.20.0.113:2379,https://172.20.0.114:2379,https://172.20.0.115:2379" # etcd config key. This is the configuration key that flannel queries # For address range assignment FLANNEL_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" ``` 如果是多网卡（例如vagrant环境），则需要在FLANNEL_OPTIONS中增加指定的外网出口的网卡，例如-iface=eth2 **在etcd中创建网络配置** 执行下面的命令为docker分配IP地址段。 ```bash etcdctl --endpoints=https://172.20.0.113:2379,https://172.20.0.114:2379,https://172.20.0.115:2379 \ --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://172.20.0.113:2379,https://172.20.0.114:2379,https://172.20.0.115:2379 \ --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"}}' ``` 如果你要使用`host-gw`模式，可以直接将vxlan改成`host-gw`即可。 **注**：参考[网络和集群性能测试](network-and-cluster-perfermance-test.md)那节，最终我们使用的`host-gw`模式，关于flannel支持的backend模式见：<https://github.com/coreos/flannel/blob/master/Documentation/backends.md>。 **启动flannel** ```bash systemctl daemon-reload systemctl enable flanneld systemctl start flanneld systemctl status flanneld ``` 现在查询etcd中的内容可以看到： ```bash $etcdctl --endpoints=${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 /kube-centos/network/subnets/172.30.14.0-24 /kube-centos/network/subnets/172.30.38.0-24 /kube-centos/network/subnets/172.30.46.0-24 $etcdctl --endpoints=${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 { "Network": "172.30.0.0/16", "SubnetLen": 24, "Backend": { "Type": "vxlan" } } $etcdctl --endpoints=${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/subnets/172.30.14.0-24 {"PublicIP":"172.20.0.114","BackendType":"vxlan","BackendData":{"VtepMAC":"56:27:7d:1c:08:22"}} $etcdctl --endpoints=${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/subnets/172.30.38.0-24 {"PublicIP":"172.20.0.115","BackendType":"vxlan","BackendData":{"VtepMAC":"12:82:83:59:cf:b8"}} $etcdctl --endpoints=${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/subnets/172.30.46.0-24 {"PublicIP":"172.20.0.113","BackendType":"vxlan","BackendData":{"VtepMAC":"e6:b2:fd:f6:66:96"}} ``` 如果可以查看到以上内容证明flannel已经安装完成，下一步是在node节点上安装和配置docker、kubelet、kube-proxy等，请参考下一节[部署node节点](node-installation.md)。