13-3 k8s网络插件-flannel安装

flannel安装：

1、yaml方式安装：
在已经安装好k8s集群之上部署flannel:
获取flannel yaml文件，应用官方的yaml文件：
若以下无法下载:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
wget https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml




1）拉取镜像问题：
yaml所使用的镜像为：quay.io/coreos/flannel:v0.14.0
若无法下载在yaml文件中可修改为其它下载地址：quay.mirrors.ustc.edu.cn/coreos/flannel:v0.14.0


2)yaml文件中指定的POD网段：根据自己需要修改网段
  net-conf.json: |

    {

      "Network": "10.244.0.0/16",

      "Backend": {

        "Type": "vxlan"

      }

    }



只需要在Master节点执行：



kubectl apply -f kube-flannel.yml
安装flanner后：
[root@vm1 k8sinstall]# kubectl get pod -n kube-system


NAME                          READY   STATUS    RESTARTS   AGE

coredns-7ff77c879f-5w99f      1/1     Running   314        5d20h

coredns-7ff77c879f-f5vtn      1/1     Running   560        7d

etcd-vm1                      1/1     Running   2          47d

kube-apiserver-vm1            1/1     Running   2          47d

kube-controller-manager-vm1   1/1     Running   56         47d

kube-flannel-ds-nmlmh         1/1     Running   0          46d

kube-flannel-ds-tqwf4         1/1     Running   0          46d

kube-flannel-ds-whkfq         1/1     Running   0          2d17h



2、二进制tar.gz包安装
https://www.cnblogs.com/linuxk/p/9272819.html
https://cloud.tencent.com/developer/article/1608835

下载安装包：https://github.com/flannel-io/flannel/releases
# wget https://github.com/flannel-io/flannel/releases/flannel-v0.14.0-linux-amd64.tar.gz
解压后：
# tar -xf flannel-v0.14.0-linux-amd64.tar.gz 

[root@vm1 flannel]# ll


-rwxr-xr-x 1 1000 1000 49333192 May 27 22:40 flanneld

-rw-r--r-- 1 root root 13083392 Oct  9 17:44 flannel-v0.14.0-linux-amd64.tar.gz

-rwxr-xr-x 1 1000 1000     2139 May 29  2019 mk-docker-opts.sh

-rw-rw-r-- 1 1000 1000     4654 Apr 15 22:39 README.md

所有节点都要操作，master和node节点均需要这2个文件：flanneld，mk-docker-opts.sh

etcd安装：
项目地址：https://github.com/etcd-io/etcd
下载地址：https://github.com/coreos/etcd/releases/download/v3.2.15/etcd-v3.2.15-linux-amd64.tar.gz
下载解压后：
cd etcd-v3.2.15-linux-amd64

[root@vm1 etcd-v3.2.15-linux-amd64]# ll



drwxr-xr-x 11 1000 1000     4096 Jan 23  2018 Documentation

-rwxr-xr-x  1 1000 1000 17833792 Jan 23  2018 etcd

-rwxr-xr-x  1 1000 1000 15246720 Jan 23  2018 etcdctl

-rw-r--r--  1 1000 1000    33849 Jan 23  2018 README-etcdctl.md

-rw-r--r--  1 1000 1000     5801 Jan 23  2018 README.md

-rw-r--r--  1 1000 1000     7855 Jan 23  2018 READMEv2-etcdctl.md

cp etcdctl /usr/local/bin/

(1)为flannel生成证书
# vim flanneld-csr.json

{

  "CN": "flanneld",

  "hosts": [],

  "key": {

    "algo": "rsa",

    "size": 2048

  },

  "names": [

    {

      "C": "CN",

      "ST": "BeiJing",

      "L": "BeiJing",

      "O": "k8s",

      "OU": "System"

    }

  ]

}
# 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
ssl]# ll flannel*

-rw-r--r-- 1 root root  997 May 31 11:13 flanneld.csr

-rw-r--r-- 1 root root  221 May 31 11:13 flanneld-csr.json

-rw------- 1 root root 1675 May 31 11:13 flanneld-key.pem

-rw-r--r-- 1 root root 1391 May 31 11:13 flanneld.pem
(2)分发证书
ssl]# cp flanneld*.pem /opt/kubernetes/ssl/
将flanneld*.pem cp到所有的节点的/opt/kubernetes/ssl目录下
（3）下载flannel软件包
cp flanneld mk-docker-opts.sh /opt/kubernetes/bin/
将flanneld，mk-docker-opts.sh cp到所有的节点的/opt/kubernetes/bin/目录下
(4)配置flannel
# vim /opt/kubernetes/cfg/flannel

FLANNEL_ETCD="-etcd-endpoints=https://192.168.56.110:2379,https://192.168.56.120:2379,https://192.168.56.130:2379"

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"
将flannel文件cp到所有的节点上
（6）设置flannel系统服务
# 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
将该文件cp到所有的节点上

2.3 flannel cni集成
1)下载cni插件
https://github.com/containernetworking/plugins/releases

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

# mkdir /opt/kubernetes/bin/cni



# tar zxf cni-plugins-amd64-v0.7.1.tgz -C /opt/kubernetes/bin/cni

所有的节点将cni/* cp到 /opt/kubernetes/bin/cni
2)创建etcd的key
此步的操作是为了创建POD的网段，并在ETCD中存储，而后FLANNEL从ETCD中取出并进行分配
# /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://192.168.56.110:2379,https://192.168.56.120:2379,https://192.168.56.130:2379 \

mk /kubernetes/network/config '{ "Network": "10.2.0.0/16", "Backend": { "Type": "vxlan", "VNI": 1 }}' >/dev/null 2>&1
3)启动flannel
# systemctl daemon-reload

# systemctl enable flannel

# chmod +x /opt/kubernetes/bin/*

# systemctl start flannel

启动后，可以看到每个节点上会多出一个flannel.1的网卡，不同的节点都在不同网段。

2.4 配置docker使用flannel
(s所有节点均需要操作)
# 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  #让docker在flannel网络后面启动

Wants=network-online.target

Requires=flannel.service 



[Service] #增加EnvironmentFile=-/run/flannel/docker

Type=notify

EnvironmentFile=-/run/flannel/docker #加载环境文件，设置docker0的ip地址为flannel分配的ip地址

ExecStart=/usr/bin/dockerd $DOCKER_OPTS



# systemctl daemon-reload

# systemctl restart docker