k8s基于kubeadm部署集群 含集群NotReady解决方案

1）简介

kubernetes简称k8s。是用于自动部署，扩展和管理容器化应用程序的开源系统。
中文官网：https://kubernetes.io/Zh/
中文社区：https://www.kubernetes.org.cn/
官方文档：https://kubernetes.io/zh/docs/home/
社区文档：https://docs.kubernetes.org.cn/

（2）主机分配

一主二从，centos7.6版本，kubectl1.7.3

（3）设置Linux环境（三个节点都执行）

• 关闭防火墙

systemctl stop firewalld
systemctl disable firewalld

• 关闭Linux

sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0

• 关闭swap

swapoff -a #临时关闭
sed -ri 's/.*swap.*/#&/' /etc/fstab #永久关闭
free -g #验证，swap必须为0

• 添加主机名与IP对应关系：

查看主机名：

hostname

hostnamectl set-hostname k8s-node1
hostnamectl set-hostname k8s-node2
hostnamectl set-hostname k8s-node3

如果主机名不正确，可以通过“hostnamectl set-hostname <newhostname> :指定新的hostname”命令来进行修改。

cat >> /etc/hosts << EOF
172.16.1.67 k8s-node3
172.16.1.68 k8s-node2
172.16.1.62 k8s-node1
EOF

将桥接的IPV4流量传递到iptables的链：

cat > /etc/sysctl.d/k8s.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

应用规则：

sysctl --system

疑难问题：遇见提示是只读的文件系统，运行如下命令

mount -o remount rw /

• date 查看时间（可选）

yum -y install ntpupdate

ntpupdate time.window.com #同步最新时间

（3）所有节点安装docker、kubeadm、kubelet、kubectl

Kubenetes默认CRI（容器运行时）为Docker，因此先安装Docker。

（1）Doker 安装

清理已经安装的docker（如果没有安装过，可以跳过此步）

yum remove docker \
    docker-client \                  
    docker-client-latest \
    docker-common \
    docker-latest \
    docker-latest-logrotate \
    docker-logrotate \
    docker-selinux \
    docker-engine-selinux \
    docker-engine

安装Device Mapper工具

yum install -y yum-utils device-mapper-persistent-data lvm2

配置docker的yum数据源

yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

更新 yum缓存

yum makecache fast

安装docker-ce（社区版）

yum -y install docker-ce docker-ce-cli containerd.io 

启动docker

systemctl start docker

开机启动

systemctl enable docker.service

重启

systemctl restart docker

启动后可以使用如下命令进行校验

 docker -v

（2）添加阿里与Yum源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

更多详情见： https://developer.aliyun.com/mirror/kubernetes

（3）安装kubeadm，kubelet和kubectl

yum list|grep kube

安装

yum install -y kubelet-1.17.3 kubeadm-1.17.3 kubectl-1.17.3

开机启动

systemctl enable kubelet && systemctl start kubelet

查看kubelet的状态： 状态是失败，但是在运行是正常的，只要组网后就会显示成功

systemctl status kubelet

查看kubelet版本：

[root@k8s-node2 ~]# kubelet --version
Kubernetes v1.17.3

4）部署k8s-master

（1）master节点初始化

在Master节点上，创建并执行master_images.sh

#!/bin/bash

images=(
	kube-apiserver:v1.17.3
    kube-proxy:v1.17.3
	kube-controller-manager:v1.17.3
	kube-scheduler:v1.17.3
	coredns:1.6.5
	etcd:3.4.3-0
    pause:3.1
)

for imageName in ${images[@]} ; do
    docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
#   docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName  k8s.gcr.io/$imageName
done

初始化kubeadm

kubeadm init \
--apiserver-advertise-address=172.16.1.62 \
--image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
--kubernetes-version   v1.17.3 \
--service-cidr=10.96.0.0/16  \
--pod-network-cidr=10.244.0.0/16

注：–apiserver-advertise-address=172.16.1.62 ：这里的IP地址是master主机的地址，为上面的eth0网卡的地址；

执行结果：

[root@k8s-node1 opt]# kubeadm init \
> --apiserver-advertise-address=172.16.1.62 \
> --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
> --kubernetes-version   v1.17.3 \
> --service-cidr=10.96.0.0/16  \
> --pod-network-cidr=10.244.0.0/16
W0503 14:07:12.594252   10124 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.17.3
[preflight] Running pre-flight checks
        [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two,depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-node1 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.2.15]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-node1 localhost] and IPs [10.0.2.15 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-node1 localhost] and IPs [10.0.2.15 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
W0503 14:07:30.908642   10124 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0503 14:07:30.911330   10124 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 22.506521 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.18" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8s-node1 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node k8s-node1 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: sg47f3.4asffoi6ijb8ljhq
[bootstrap-token] Configuring bootstrap tokens,cluster-info ConfigMap,RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
#表示kubernetes已经初始化成功了
Your Kubernetes control-plane has initialized successfully!

To start using your cluster,you need to run the following as a regular user:

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

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 10.0.2.15:6443 --token sg47f3.4asffoi6ijb8ljhq \
    --discovery-token-ca-cert-hash sha256:81fccdd29970cbc1b7dc7f171ac0234d53825bdf9b05428fc9e6767436991bfb 
[root@k8s-node1 opt]# 

由于默认拉取镜像地址k8s.cr.io国内无法访问，这里指定阿里云仓库地址。可以手动按照我们的images.sh先拉取镜像。

地址变为：registry.aliyuncs.com/googole_containers也可以。
科普：无类别域间路由（Classless Inter-Domain Routing 、CIDR）是一个用于给用户分配IP地址以及在互联网上有效第路由IP数据包的对IP地址进行归类的方法。
拉取可能失败，需要下载镜像。

运行完成提前复制：加入集群的令牌。

（2）测试Kubectl（主节点执行）

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

详细部署文档：https://kubernetes.io/docs/concepts/cluster-administration/addons/

$ kubectl get nodes #获取所有节点

目前Master状态为notready。等第七步组网，网络加入完成即可。

$ journalctl -u kubelet #查看kubelet日志

（5）安装POD网络插件（CNI）

在master节点上执行按照POD网络插件

kubectl apply -f \
https://raw.githubusercontent.com/coreos/flanne/master/Documentation/kube-flannel.yml

[root@k8s-node1 k8s]# kubectl apply -f  kube-flannel.yml    
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds-amd64 created
daemonset.apps/kube-flannel-ds-arm64 created
daemonset.apps/kube-flannel-ds-arm created
daemonset.apps/kube-flannel-ds-ppc64le created
daemonset.apps/kube-flannel-ds-s390x created
[root@k8s-node1 k8s]#

同时flannel.yml中指定的images访问不到可以去docker hub找一个wget yml地址
vi 修改yml 所有amd64的地址修改了即可
等待大约3分钟
查看指定名称空间的pods

kubectl get pods -n kube-system 

查看所有名称空间的pods

kubectl get pods --all-namespaces

执行watch kubectl get pod -n kube-system -o wide 监控pod进度，等待3-10分钟，完全都是running以后继续

查看命名空间：

[root@k8s-node1 k8s]# kubectl get ns
NAME              STATUS   AGE
default           Active   30m
kube-node-lease   Active   30m
kube-public       Active   30m
kube-system       Active   30m
[root@k8s-node1 k8s]#

[root@k8s-node1 k8s]# kubectl get pods --all-namespaces       
NAMESPACE     NAME                                READY   STATUS    RESTARTS   AGE
# coredns 在主节点ready之后会调度成功
kube-system   coredns-546565776c-9sbmk            0/1     Pending   0          31m
kube-system   coredns-546565776c-t68mr            0/1     Pending   0          31m
kube-system   etcd-k8s-node1                      1/1     Running   0          31m
kube-system   kube-apiserver-k8s-node1            1/1     Running   0          31m
kube-system   kube-controller-manager-k8s-node1   1/1     Running   0          31m
kube-system   kube-flannel-ds-amd64-6xwth         1/1     Running   0          2m50s
kube-system   kube-proxy-sz2vz                    1/1     Running   0          31m
kube-system   kube-scheduler-k8s-node1            1/1     Running   0          31m

查看master上的节点信息：

[root@k8s-node1 k8s]# kubectl get nodes
NAME        STATUS   ROLES    AGE   VERSION
k8s-node1   NotReady    master   34m   v1.17.3 

如果master一直没有ready，查看日志报错：[failed to find plugin “flannel” in path [/opt/cni/bin]]

解决结点NotReady方案

github下载地址：https://github.com/containernetworking/plugins/releases/tag/v0.8.6

下载后上传到Linux /k8s目录解压

tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz

复制 flannel 到 /opt/cni/bin/

cp flannel /opt/cni/bin/

再查看状态

[root@k8s-node1 k8s]# kubectl get nodes
NAME        STATUS   ROLES    AGE   VERSION
k8s-node1   NotReady    master   34m   v1.17.3   #status为ready才能够执行下面的命令

最后再次执行，并且分别在“k8s-node2”和“k8s-node3”上也执行这里命令：

# 请使用当时生成的token,不要复制这个
kubeadm join 172.16.1.62:6443 --token zy7rjn.60c64bs6a9fiiw8n     --discovery-token-ca-cert-hash sha256:73cb3ebfdee05b40824c93e6ec470b5eeff128c0bdab433bfe720f8050ded1aa 
# 如果没记录token,在主节点执行:
kubeadm token create --print-join-command

[root@k8s-node1 opt]# kubectl get nodes
NAME        STATUS     ROLES    AGE   VERSION
k8s-node1   Ready      master   47m   v1.17.3
k8s-node2   NotReady   <none>   75s   v1.17.3
k8s-node3   NotReady   <none>   76s   v1.17.3

监控pod进度

watch kubectl get pod -n kube-system -o wide

如果监控状态都running了,但是从节点没有ready

1、在从节点查看日志

[root@k8s-node2 ~]# journalctl -u kubelet -f

2、如果是: [failed to find plugin “flannel” in path [/opt/cni/bin]],则和前面master一样解决

[root@k8s-node1 ~]#  kubectl get nodes;                         
NAME        STATUS   ROLES    AGE     VERSION
k8s-node1   Ready    master   3h50m   v1.17.3
k8s-node2   Ready    <none>   3h3m    v1.17.3
k8s-node3   Ready    <none>   3h3m    v1.17.3
[root@k8s-node1 ~]# 

(6）加入kubenetes的Node节点

token过期怎么办

kubeadm token create --print-join-command

原文地址：https://blog.csdn.net/mr_zhu_wenxing/article/details/128506782