kubernetes学习（三）CNI网络插件安装

上一篇文章

https://editor.youkuaiyun.com/md/?articleId=151062776
kubernetes学习（二）通过kubeadm安装kubernetes（master节点启动）

配置

在（二）中初始化成功之后，末尾会需要一些配置

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

这里的$HOME不单指当前执行的用户的HOME，root的也要做配置
否则会出现在安装CNI网络插件时，由于没有配置，访问本地8080导致端口被拒

# 错误提示
The connection to the server localhost:8080 was refused - did you specify the right host or port?

  mkdir -p root/.kube
  sudo cp -i /etc/kubernetes/admin.conf root/.kube/config
  sudo chown $(id -u):$(id -g) root/.kube/config

安装插件

这里用的是flannel
可以先wget下载下来

wget https://raw.githubusercontent.com/flannel-io/flannel/master/Documentation/kube-flannel.yml

修改插件配置

net-conf.json字段内，跟kubernetes的子网掩码一致

{
  "Network": "169.169.0.0/16",
  "Backend": {
    "Type": "vxlan"
  }
}

安装

kubectl apply  -f  kube-flannel.yml

安装完成后，查看pod和node

lu@192:~/download$ sudo kubectl get pods --all-namespaces
NAMESPACE      NAME                             READY   STATUS    RESTARTS   AGE
kube-flannel   kube-flannel-ds-lhvfb            1/1     Running   0          19s
kube-system    coredns-6d58d46f65-c4fvs         1/1     Running   0          4m54s
kube-system    coredns-6d58d46f65-lcxjf         1/1     Running   0          4m54s
kube-system    etcd-master                      1/1     Running   10         5m
kube-system    kube-apiserver-master            1/1     Running   0          5m
kube-system    kube-controller-manager-master   1/1     Running   0          60s
kube-system    kube-proxy-2t4hq                 1/1     Running   0          4m55s
kube-system    kube-scheduler-master            1/1     Running   13         4m59s

lu@192:~/download$ sudo kubectl get nodes
NAME     STATUS   ROLES           AGE     VERSION
master   Ready    control-plane   4m58s   v1.30.14

如果想删除

kubectl delete -f <apply的文件>

查看funnel执行情况

kubectl describe pod kube-flannel-ds-rtlfh -n kube-flannel
kubectl logs -n kube-flannel kube-flannel-ds-rtlfh -c kube-flannel

安装可能遇到的问题

1 flannel安装失败
原因：
br_netfilter没有安装或者配置
解决方案：

sudo modprobe br_netfilter

echo "br_netfilter" | sudo tee /etc/modules-load.d/br_netfilter.conf

2 flannel的pod启动失败
2.1 原因：

E0826 04:53:41.827892       1 main.go:276] Failed to check br_netfilter: stat /proc/sys/net/bridge/bridge-nf-call-iptables: no such file or directory

解决方案：

cat > /etc/sysctl.d/k8s.conf << EOF
net.ipv4.ip_forward = 1 # 开启路由转发
net.bridge.bridge-nf-call-ip6tables = 1 # 开启桥流量监控
net.bridge.bridge-nf-call-iptables = 1 # 开启桥流量监控

2.2 原因：

E0826 05:01:08.447320       1 main.go:367] Error registering network: failed to acquire lease: node "master" pod cidr not assigned
I0826 05:01:08.447395       1 main.go:499] Stopping shutdownHandler...

解决方案：

vi /etc/kubernetes/manifests/kube-controller-manager.yaml

--allocate-node-cidrs=true
--cluster-cidr=192.168.0.0/16