K8s集群部署（四）------ Flannel网络部署

所有节点都要部署Flannel网络，在所有节点操作。

1.为Flannel生成证书

[root@k8s-master ssl]# pwd
/usr/local/src/ssl

[root@k8s-master ssl]# vim flanneld-csr.json
{
  "CN": "flanneld",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

2.生成证书

[root@k8s-master ssl]# cfssl gencert -ca=/opt/kubernetes/ssl/ca.pem 
>    -ca-key=/opt/kubernetes/ssl/ca-key.pem 
>    -config=/opt/kubernetes/ssl/ca-config.json 
>    -profile=kubernetes flanneld-csr.json | cfssljson -bare flanneld

3.分发证书

[root@k8s-master ssl]# cp flanneld*.pem /opt/kubernetes/ssl/
[root@k8s-master ssl]# scp flanneld*.pem 10.0.3.226:/opt/kubernetes/ssl/
[root@k8s-master ssl]# scp flanneld*.pem 10.0.3.227:/opt/kubernetes/ssl/

4.下载Flannel软件包

[root@k8s-master ssl]# cd /usr/local/src
[root@k8s-master src]# tar zxf flannel-v0.10.0-linux-amd64.tar.gz
[root@k8s-master src]# cp flanneld mk-docker-opts.sh /opt/kubernetes/bin/
#复制到Node节点
[root@k8s-master src]# scp flanneld mk-docker-opts.sh 10.0.3.226:/opt/kubernetes/bin/                 
[root@k8s-master src]# scp flanneld mk-docker-opts.sh 10.0.3.227:/opt/kubernetes/bin/         

 #复制对应脚本到/opt/kubernetes/bin下                              
[root@k8s-master src]# cd /usr/local/src/kubernetes/cluster/centos/node/bin/
[root@k8s-master bin]# cp remove-docker0.sh /opt/kubernetes/bin/
[root@k8s-master bin]# scp remove-docker0.sh 192.168.56.12:/opt/kubernetes/bin/
^C[root@k8s-master bin]# scp remove-docker0.sh 10.0.3.226:/opt/kubernetes/bin/
[root@k8s-master bin]# scp remove-docker0.sh 10.0.3.227:/opt/kubernetes/bin/

下载地址：
# wget　https://github.com/coreos/flannel/releases/download/v0.10.0/flannel-v0.10.0-linux-amd64.tar.gz

5.配置Flannel

[root@k8s-master bin]# vim /opt/kubernetes/cfg/flannel
FLANNEL_ETCD="-etcd-endpoints=https://10.0.3.225:2379,https://10.0.3.226:2379,https://10.0.3.227:2379"
FLANNEL_ETCD_KEY="-etcd-prefix=/kubernetes/network"
FLANNEL_ETCD_CAFILE="--etcd-cafile=/opt/kubernetes/ssl/ca.pem"
FLANNEL_ETCD_CERTFILE="--etcd-certfile=/opt/kubernetes/ssl/flanneld.pem"
FLANNEL_ETCD_KEYFILE="--etcd-keyfile=/opt/kubernetes/ssl/flanneld-key.pem"


复制配置到其它节点上
[root@linux-node1 ~]# scp /opt/kubernetes/cfg/flannel 10.0.3.226:/opt/kubernetes/cfg/
[root@linux-node1 ~]# scp /opt/kubernetes/cfg/flannel 10.0.3.227:/opt/kubernetes/cfg/

6.设置Flannel系统服务

[root@linux-node1 ~]# vim /usr/lib/systemd/system/flannel.service
[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
Before=docker.service

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/flannel
ExecStartPre=/opt/kubernetes/bin/remove-docker0.sh
ExecStart=/opt/kubernetes/bin/flanneld ${FLANNEL_ETCD} ${FLANNEL_ETCD_KEY} ${FLANNEL_ETCD_CAFILE} ${FLANNEL_ETCD_CERTFILE} ${FLANNEL_ETCD_KEYFILE}
ExecStartPost=/opt/kubernetes/bin/mk-docker-opts.sh -d /run/flannel/docker

Type=notify

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

复制系统服务脚本到其它节点上
# scp /usr/lib/systemd/system/flannel.service 10.0.3.226:/usr/lib/systemd/system/
# scp /usr/lib/systemd/system/flannel.service 10.0.3.227:/usr/lib/systemd/system/

Flannel CNI集成

1.下载CNI插件

下载地址：https://github.com/containernetworking/plugins/releases
wget https://github.com/containernetworking/plugins/releases/download/v0.7.1/cni-plugins-amd64-v0.7.1.tgz


[root@linux-node1 ~]# mkdir /opt/kubernetes/bin/cni
[root@linux-node1 src]# tar zxf cni-plugins-amd64-v0.7.1.tgz -C /opt/kubernetes/bin/cni
# scp -r /opt/kubernetes/bin/cni/* 10.0.3.226:/opt/kubernetes/bin/cni/
# scp -r /opt/kubernetes/bin/cni/* 10.0.3.227:/opt/kubernetes/bin/cni/

2.创建Etcd的key

/opt/kubernetes/bin/etcdctl --ca-file /opt/kubernetes/ssl/ca.pem --cert-file /opt/kubernetes/ssl/flanneld.pem --key-file /opt/kubernetes/ssl/flanneld-key.pem 
      --no-sync -C https://10.0.3.225:2379,https://10.0.3.226:2379,https://10.0.3.227:2379 
mk /kubernetes/network/config '{ "Network": "10.2.0.0/16", "Backend": { "Type": "vxlan", "VNI": 1 }}' >/dev/null 2>&1

3.启动flannel

[root@k8s-master src]# systemctl daemon-reload
[root@k8s-master src]# systemctl enable flannel
[root@k8s-master src]# chmod +x /opt/kubernetes/bin/*
[root@k8s-master src]# systemctl start flannel

4.查看服务状态

[root@k8s-master src]# systemctl status flannel

配置Docker使用Flannel

[root@k8s-mastrt ~]# vim /usr/lib/systemd/system/docker.service
[Unit] #在Unit下面修改After和增加Requires
After=network-online.target firewalld.service flannel.service
Wants=network-online.target
Requires=flannel.service

[Service] #增加EnvironmentFile=-/run/flannel/docker
Type=notify
EnvironmentFile=-/run/flannel/docker
ExecStart=/usr/bin/dockerd $DOCKER_OPTS

将配置复制到另外两个节点

# scp /usr/lib/systemd/system/docker.service 10.0.3.226:/usr/lib/systemd/system/
# scp /usr/lib/systemd/system/docker.service 10.0.3.227:/usr/lib/systemd/system/

重启Docker

[root@k8s-master ~]# systemctl daemon-reload
[root@k8s-master ~]# systemctl restart docker

执行ifconfig可以看到docker容器 和 Flannel在一个网段。