Kubernetes: 集群网络配置 - flannel

参考: [ Kubernetes 权威指南 ]
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Kubernetes 集群搭建能够参考 [ Kubernetes : 多节点 k8s 集群实践 ] <br>

在多个 Node 组成的 Kubernetes 集群内, Kubernetes 自己不会对跨主机容器网络进行设置. flannel 就是解决跨主机容器间网络互通的需求. <br><br>

Kubernetes 集群架构

Server List

节点名称	节点 IP
k8s-master	10.10.10.10
k8s-node1	10.10.10.11
k8s-node2	10.10.10.12

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节点服务说明

• Master : etcd , kube-apiserver , kube-controller-manager, kube-scheduler.

• Node : docker, kubelet, kube-proxy <br><br>

flannel 配置安装

flannel 安装于 kubernetes node 服务器上.

安装 flannel

yum install flannel
ln -sv /usr/libexec/flannel/mk-docker-opts.sh /usr/bin

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配置: /etc/sysconfig/flanneld

须要链接位于 master 上的 etcd 服务:

FLANNEL_ETCD_ENDPOINTS="http://10.10.10.10:2379"
FLANNEL_ETCD_PREFIX="/myk8s/network" # myk8s 能够随意定义

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在 etcd 中添加网络配置记录

etcdctl set /myk8s/network/config '{"Network":"10.1.0.0/16"}'

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修改文件: /usr/lib/systemd/system/flanneld.service

[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=network-online.target
#After=etcd.service # 不在本机部署 etcd
Wants=network-online.target
Before=docker.service

[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/flanneld
EnvironmentFile=-/etc/sysconfig/docker-network
ExecStart=/usr/bin/flanneld-start $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
WantedBy=docker.service

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服务启动

systemctl stop docker
systemctl start flanneld

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配置 Docker 网桥

mk-docker-opts.sh -i
source /run/flannel/subnet.env
ifconfig docker0 ${FLANNEL_SUBNET}

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重启服务

systemctl start docker
systemctl restart kubelet
systemctl restart kube-proxy