【K8S环境搭建】

K8S环境搭建

[root@node2 ~]# yum install ntpdate -y 安装时间同步

[root@master ~]# ntpdate time.windows.com 开启时间同步

[root@node2 ~]# yum -y install ipset ipvsadm 安装ipset和ipsadm

关闭防火墙

systemctl disable firewalld
systemctl stop firewalld

关闭selinux

临时禁用selinux

setenforce 0

永久关闭 修改/etc/sysconfig/selinux文件设置

sed -i ‘s/SELINUX=permissive/SELINUX=disabled/’ /etc/sysconfig/selinux
sed -i “s/SELINUX=enforcing/SELINUX=disabled/g” /etc/selinux/config

禁用交换分区

swapoff -a

永久禁用，打开/etc/fstab注释掉swap那一行。

sed -i ‘s/.swap./#&/’ /etc/fstab

修改内核参数

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

sysctl --system

安装docker k8s 3台服务器同时进行

## 获取镜像

wget http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O  /etc/yum.repos.d/docker-ce.repo

##刷新yum源

yum clean all

yum makecache

1. 安装docker（三台节点）

   yum -y install docker-ce-18.06.1.ce-3.el7
   

   ###启动docker并设置开机自启

   systemctl enable docker && systemctl start docker
   

2. vim /etc/docker/daemon.json 修改配置文件3个节点都需要

   { "exec-opts": ["native.cgroupdriver=systemd"] }
   

   重启docker systemctl restart docker

所有节点都要配置kubeadm,kubelet,kubectl镜像

kubelet：运行在集群所有节点上,负责启动POD和容器

kubeadm：用于初始化集群

kubectl：kubenetes命令行工具，通过kubectl可以部署和管理应用，查看各种资源，创建，删除和更新组件

–创建源文件

vim 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

创建好的源文件放入指定目录下

mv kubernetes.repo  /etc/yum.repos.d/

下载 kubelet

yum install -y kubelet-1.14.1

yum install -y kubeadm-1.14.1 kubectl-1.14.1

设置开启启动

systemctl enable kubelet

设置k8s 为插件为systemd

vim /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf

在KUBELET_KUBECONFIG_ARGS 后面追加 --cgroup-driver=systemd

Environment=“KUBELET_KUBECONFIG_ARGS=–bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --cgroup-driver=systemd”

初始化节点

sudo docker pull mirrorgooglecontainers/kube-apiserver:v1.14.1
sudo docker pull mirrorgooglecontainers/kube-controller-manager:v1.14.1
sudo docker pull mirrorgooglecontainers/kube-scheduler:v1.14.1
sudo docker pull mirrorgooglecontainers/kube-proxy:v1.14.1
sudo docker pull mirrorgooglecontainers/pause:3.1
sudo docker pull mirrorgooglecontainers/etcd:3.3.10
sudo docker pull coredns/coredns:1.3.1

sudo docker tag mirrorgooglecontainers/kube-apiserver:v1.14.1 k8s.gcr.io/kube-apiserver:v1.14.1
sudo docker tag mirrorgooglecontainers/kube-controller-manager:v1.14.1 k8s.gcr.io/kube-controller-manager:v1.14.1
sudo docker tag mirrorgooglecontainers/kube-scheduler:v1.14.1 k8s.gcr.io/kube-scheduler:v1.14.1
sudo docker tag mirrorgooglecontainers/kube-proxy:v1.14.1 k8s.gcr.io/kube-proxy:v1.14.1
sudo docker tag mirrorgooglecontainers/pause:3.1 k8s.gcr.io/pause:3.1
sudo docker tag mirrorgooglecontainers/etcd:3.3.10 k8s.gcr.io/etcd:3.3.10
sudo docker tag coredns/coredns:1.3.1 k8s.gcr.io/coredns:1.3.1

kubeadm init  --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.6.153 --kubernetes-version=v1.14.1 --ignore-preflight-errors=Swap 

 
--pod-network-cidr是指配置节点中的pod的可用IP地址，此为内部IP
--apiserver-advertise-address 为master的IP地址
--kubernetes-version 通过kubectl version 可以查看到

然后执行三行命令

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

安装容器pod网络 主节点就不会NotReady

wget https://docs.projectcalico.org/v3.14/manifests/calico.yaml --no-check-certificate

​ kubectl apply -f calico.yaml

复制admin.conf文件到节点机器

scp /etc/kubernetes/admin.conf [email protected]:/root/
scp /etc/kubernetes/admin.conf [email protected]:/root/

初始化的时候出现的命令 节点加入集群命令

kubeadm join 192.168.6.153:6443 --token 3zvmgf.suatjacffpos1jhq \
    --discovery-token-ca-cert-hash sha256:dd3a2b886ea24685a1d61fe40c60d9416278e9f50974c608c9a3269c1acd82a8

#查看节点信息

kubectl get nodes

#节点不能使用get nodes命令

需要把master 上admin.conf文件拿到node节点上来

cp -i admin.conf /etc/kubernetes/admin.conf

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

出现cp: 无法创建普通文件"/root/.kube/config": 没有那个文件或目录

#创建一个文件夹在执行一次

mkdir /root/.kube/

k8s初始化失败

kubernetes 安装时需要从 k8s.gcr.io 拉取镜像，但是该网站被我国屏蔽了，国内没法正常访问导致没法正常进行kubernetes正常安装。

这里通过介绍从Docker官方默认镜像平台拉取镜像并重新打tag的方式来绕过对 k8s.gcr.io 的访问。

https://blog.csdn.net/happyworld1/article/details/106259080/

重新初始化

# 重启kubeadm

kubeadm reset

执行玩了在重新初始化

安装过程问题汇总

Execution phase preflight

kubeadm reset

Connection refuse

systemctl restart kubelet

the connection to the server localhost:8080 was refuse

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

Unable to connection to the server :X509

rm -rf $HOME/.kube

Port is in use

kubeadm reset

节点状态NotReady

[root@k8s-node1 ~]# docker pull jmgao1983/flannel

[root@k8s-master~]# mkdir -p /etc/cni/net.d/
[root@k8s-master~]# cat < /etc/cni/net.d/10-flannel.conf
> {"name":"cbr0","type":"flannel","delegate": {"isDefaultGateway": true}}
> EOF
[root@k8s-master~]# mkdir /usr/share/oci-umount/oci-umount.d -p
[root@k8s-master~]# mkdir /run/flannel/    
	mkdir: 无法创建目录"/run/flannel/": 
[root@k8s-master~]# cat < /run/flannel/subnet.env
> FLANNEL_NETWORK=192.168.0.0/16
> FLANNEL_SUBNET=192.168.1.0/24
> FLANNEL_MTU=1450
> FLANNEL_IPMASQ=true
> EOF

systemctl restart kubelet 重启

k8s常用命令

各种组件启动

systemctl start etcd

systemctl start docker

systemctl start kube-apiserver

systemctl start kube-controller-manager

systemctl start kube-scheduler

systemctl start kubelet

systemctl start kube-proxy

systemctl enable docker

systemctl start docker

systemctl enable kubelet

重启

systemctl daemon-reload

systemctl restart kube-apiserver

systemctl status kube-apiserver

systemctl restart kube-controller-manager

systemctl status kube-controller-manager

systemctl restart kube-scheduler

systemctl status kube-scheduler

systemctl restart kubelet

systemctl status kubelet

systemctl restart kube-proxy

systemctl status kube-proxy

查看node

kubectl get nodes

kubectl get pod --all-namespaces

kubectl get pods --namespace=kube-system

kubectl get pods -n kube-system -owide | grep cambricon-precision-3630-tower

删除pod

kubectl delete -f myjob.yml

kubectl delete pod coredns-bccdc95cf-mvxnb --grace-period=0 --force -n kube-system pod

描述pod

kubectl describe pod name

删除node

kubectl delete node nodename

执行

kubectl exec -it mlutestpod bash

查看当前可用的API****版本

kubectl api-versions

节点日志

journalctl -f -u kubelet

kubectl describe nodes k8s111

pod日志

kubectl describe pods cambricon-mlu-monitor-m6kdz -n kube-system

把集群日志输出到文件

kubectl cluster-info dump --output-directory=/root/cluster-state