【kubernetes 问题排查】使用 kubeadm 部署时遇到的问题

引言

再使用kubeadm部署集群时会多少遇到一些问题，这里做下记录，方便后面查找问题时有方向，同时也为刚要入坑的你指明下方向，让你少走点弯路

问题汇总

• The connection to the server localhost:8080 was refused - did you specify the right host or port?

# root 用户
  export KUBECONFIG=/etc/kubernetes/admin.conf

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

• failed to run Kubelet: misconfiguration: kubelet cgroup driver: “systemd“ is different from docker

{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}

• Unable to connect to the server: x509: certificate signed by unknown authority (possibly because of "crypto/rsa: verification error" while trying to verify candidate authority certificate "kubernetes")

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl get nodes
export KUBECONFIG=/etc/kubernetes/kubelet.conf
kubectl get node

• Kubeadm：如何解决kubectl get cs显示scheduler Unhealthy，controller-manager Unhealthy

root用户

配置文件路径为：

/etc/kubernetes/manifests/kube-scheduler.yaml

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

user账号

$HOME/.kube/

将两个配置文件中 –port 注释掉

• 解决 Kubernetes 中 Kubelet 组件报 failed to get cgroup 错误

http://www.mydlq.club/article/80/

• 解决k8s"failed to set bridge addr: "cni0" already has an IP address different from 10.244.1.1/24"
  
  具体原因

ifconfig cni0 down
ip link delete cni0

• 查看kubelet日志

journalctl -xeu kubelet

高可用 HA

• Haproxy

  查看 haproxy.cfg 配置文件

  global
  log 127.0.0.1 local0
  log 127.0.0.1 local1 notice
  maxconn 4096
  #chroot /usr/share/haproxy
  #user haproxy
  #group haproxy
  #daemon
  stats socket /var/lib/haproxy/stats
  
  defaults
      mode                    http
      log                     global
      option                  httplog
      option                  dontlognull
      option http-server-close
      option forwardfor       except 127.0.0.0/8
      option                  redispatch
      retries                 3
      timeout http-request    10s
      timeout queue           1m
      timeout connect         10s
      timeout client          1m
      timeout server          1m
      timeout http-keep-alive 10s
      timeout check           10s
      maxconn                 3000
  
  frontend kube-apiserver
  bind *:6444
  mode tcp
  timeout client 1h
  log global
  option tcplog
  
  default_backend kube-apiserver
  
  backend kube-apiserver
  option httpchk GET /healthz
  http-check expect status 200
  mode tcp
  option ssl-hello-chk
  balance     roundrobin
  balance roundrobin
    server k8s-master01 192.168.4.41:6443 check #主要配置这里
    server k8s-master02 192.168.4.42:6443 check
    server k8s-master03 172.17.0.66:6443 check
  
  

  docker run -d --restart=always --name haproxy -p 6444:6444 \
      -v ~/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg \
      haproxy
  

• Keepalived

  • ip address associated with VRID 160 not present in MASTER advert : xx.xx.xx.xx

    可能是keepalive master的virtual_router_id和局域网内的其它的keepalive master的virtual_router_id有冲突
    
    修改 /etc/keepalived/keepalived.conf 中的 virtual_router_id 重启即可

  • 配置文件详解

  https://blog.csdn.net/u012758088/article/details/76599500

    #!/bin/bash
    VIRTUAL_IP=192.168.4.200 # 设置虚拟IP
    INTERFACE=eth0 #所使用的的网卡
    NETMASK_BIT=24
    CHECK_PORT=6444
    RID=10
    VRID=160 #虚拟路由ID 需要唯一
    MCAST_GROUP=224.0.0.18
  
    docker run -itd --restart=always --name=Keepalived-K8S \
            --net=host --cap-add=NET_ADMIN \
            -e VIRTUAL_IP=$VIRTUAL_IP \
            -e INTERFACE=$INTERFACE \
            -e CHECK_PORT=$CHECK_PORT \
            -e RID=$RID \
            -e VRID=$VRID \
            -e NETMASK_BIT=$NETMASK_BIT \
            -e MCAST_GROUP=$MCAST_GROUP \
            wise2c/keepalived-k8s
  

  使用 ip addr 即可看到所设置网卡上的虚拟IP(PS:ifconfig是看不到的)