kubernete入门学习二--安装

╰半橙微兮° 2022-03-18 02:54 340阅读 0赞

**一、总体架构**

etcd 一款开源软件。提供可靠的分布式数据存储服务，用于持久化存储K8s集群的配置和状态。

K8s API server 用户程序（如kubectl）、K8s其它组件之间通信的接口。K8s其它组件之间不直接通信，而是通过API server通信的。这一点在上图的连接中可以体现，例如，只有API server连接了etcd，即其它组件更新K8s集群的状态时，只能通过API server读写etcd中的数据。

Scheduler 排程组件，为用户应用的每一可部署组件分配工作结点。

Controller Manager 执行集群级别的功能，如复制组件、追踪工作结点状态、处理结点失败等。Controller Manager组件是由多个控制器组成的，其中很多控制器是按K8s的资源类型划分的，如Replication Manager（管理ReplicationController 资源），ReplicaSet Controller，PersistentVolume controller。

kube-proxy 在应用组件间负载均衡网络流量。

Kubelet 管理工作结点上的容器。

Container runtime Docker, rkt等实际运行容器的组件

API Server作为kubernetes系统的入口，封装了核心对象的增删改查操作，以[RESTFul][]接口方式提供给外部客户和内部组件调用。

### **二、两种部署方式：** ###

1.  k8s、docke等组件r都是直接安装到物理机上（系统级别的守护进程）--传统手动方式--复杂--网上也有相关脚本

1.  Kubeadm方式--kubelet和docker部署到物理机上，其他组件以容器方式部署为pod。--简单--静态pod （也可以运行为动态pod）

### **三、部署步骤（以上第二种模式安装）** ###

1.  Master，nodes：安装kubelet、kubadm、docker
2.  Master：kubadm init
3.  Nodes：kubadm join

### **四：实验部署** ###

host  
192.168.6.100 master  
192.168.6.101 node1  
192.168.6.102 node2

pod的默认ip 为 10.244.0.0/16  
service的默认ip  10.92.0.0/12  
节点网络为：172.20.0.0/16

系统初始化  
关闭防火墙等  
echo 1 > /proc/sys/net/bridge/bridge-nf-call-ip6tables   
echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables

wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

vi /etc/yum.repos.d/kubernetes.repo  
\[kubernetes\]  
name=Kubernetes  
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86\_64  
enabled=1  
gpgcheck=0

然后yum repolist验证是否可用

wget http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg  
rpm --import yum-key.gpg

yum install docker-ce kubelet kubeadm kubectl

启动docker服务  
systemctl daemon-reload  
systemctl start docker  
systemctl enable docker  
docker info

key  
\[root@master ~\]\# ssh-keygen  
\[root@master ~\]\# ssh-copy-id root@192.168.6.101  
\[root@master ~\]\# ssh-copy-id root@192.168.6.102  
\[root@master ~\]\# ssh node1  
The authenticity of host 'node1 (192.168.6.101)' can't be established.  
ECDSA key fingerprint is SHA256:Xz7Q7WFVuisRYJASODutHkF//Kw/RJZPpondCB6US7o.  
ECDSA key fingerprint is MD5:ae:cc:de:f5:09:a4:e3:ec:2b:1a:93:3f:49:60:5f:b1.  
Are you sure you want to continue connecting (yes/no)? yes  
Warning: Permanently added 'node1' (ECDSA) to the list of known hosts.  
Last login: Mon Feb 25 08:28:30 2019 from 10.249.100.226  
\[root@node01 ~\]\# exit  
logout  
Connection to node1 closed.

\[root@master ~\]\# kubeadm config images list  
I0225 22:03:15.247260   35483 version.go:94\] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get https://storage.googleapis.com/kubernetes-release/release/stable-1.txt: net/http: request canceled (Client.Timeout exceeded while awaiting headers)  
I0225 22:03:15.248140   35483 version.go:95\] falling back to the local client version: v1.13.3  
k8s.gcr.io/kube-apiserver:v1.13.3  
k8s.gcr.io/kube-controller-manager:v1.13.3  
k8s.gcr.io/kube-scheduler:v1.13.3  
k8s.gcr.io/kube-proxy:v1.13.3  
k8s.gcr.io/pause:3.1  
k8s.gcr.io/etcd:3.2.24  
k8s.gcr.io/coredns:1.2.6

docker pull mirrorgooglecontainers/kube-apiserver-amd64:v1.13.3  
docker pull mirrorgooglecontainers/kube-controller-manager-amd64:v1.13.3  
docker pull mirrorgooglecontainers/kube-scheduler-amd64:v1.13.3  
docker pull mirrorgooglecontainers/kube-proxy-amd64:v1.13.3  
docker pull mirrorgooglecontainers/pause:3.1  
docker pull mirrorgooglecontainers/etcd-amd64:3.2.24  
docker pull coredns/coredns:1.2.6

docker tag mirrorgooglecontainers/kube-apiserver-amd64:v1.13.3 k8s.gcr.io/kube-apiserver:v1.13.3  
docker tag mirrorgooglecontainers/kube-controller-manager-amd64:v1.13.3 k8s.gcr.io/kube-controller-manager:v1.13.3  
docker tag mirrorgooglecontainers/kube-scheduler-amd64:v1.13.3 k8s.gcr.io/kube-scheduler:v1.13.3  
docker tag mirrorgooglecontainers/kube-proxy-amd64:v1.13.3 k8s.gcr.io/kube-proxy:v1.13.3  
docker tag mirrorgooglecontainers/pause:3.1 k8s.gcr.io/pause:3.1  
docker tag mirrorgooglecontainers/etcd-amd64:3.2.24 k8s.gcr.io/etcd:3.2.24  
docker tag coredns/coredns:1.2.6 k8s.gcr.io/coredns:1.2.6

kubeadm init  --kubernetes-version=v1.13.3 --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12 --ignore-preflight-errors=Swap

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

保存，客户端执行  
kubeadm join 192.168.6.100:6443 --token 2wh7mm.9zd1w12wyuqsdm7i --discovery-token-ca-cert-hash sha256:d0864f7935eff8a635f134e767c85b1a99629d3bc13508d3fc1c586e8a7f55b4

组件状态信息  
kubectl get cs  
kubectl get componentstatus

节点信息  
kubectl get nodes

\[root@master ~\]\# kubectl get nodes  
NAME     STATUS   ROLES    AGE   VERSION  
master   Ready    master   24h   v1.13.3

\---------------------------------------  
部署网络  
https://github.com/coreos/flannel  
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml  
docker images ls  
kubectl get pods  
kubectl get pods -n kube-system  
kubectl get ns

\[root@master ~\]\# kubectl get pods --all-namespaces  
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE  
kube-system   coredns-86c58d9df4-29lwf         1/1     Running   0          21m  
kube-system   coredns-86c58d9df4-5n755         1/1     Running   0          21m  
kube-system   etcd-master                      1/1     Running   0          20m  
kube-system   kube-apiserver-master            1/1     Running   0          20m  
kube-system   kube-controller-manager-master   1/1     Running   0          20m  
kube-system   kube-flannel-ds-amd64-6fj5c      1/1     Running   0          10m  
kube-system   kube-proxy-ldskb                 1/1     Running   0          21m  
kube-system   kube-scheduler-master            1/1     Running   0          20m

维护命令  
kubectl --namespace kube-system logs  kube-flannel-ds-amd64-6fj5c  
\-------------------------------  
相关仓库文件scp到客户端  
将docker和kubelet设置为开机启动  
启动docker

客户端安装  
yum install docker-ce kubelet kubeadm  
执行之前服务器的命令  
这里遇到token过期，重新生成token即可  
kubeadm join 192.168.6.100:6443 --token o6vu26.dlq1knjxwqq93aht --discovery-token-ca-cert-hash sha256:d0864f7935eff8a635f134e767c85b1a99629d3bc13508d3fc1c586e8a7f55b4

\[root@master ~\]\# kubectl get nodes  
NAME     STATUS     ROLES    AGE    VERSION  
master   Ready      master   25h    v1.13.3  
node01   NotReady   <none>   49s    v1.13.3  
node02   NotReady   <none>   105s   v1.13.3  
这里环境安装完成  
==================  
错误一  
启动kubelet报错（这里不能先启动，要先初始化）  
Feb 25 21:56:53 master systemd: kubelet.service holdoff time over, scheduling restart.  
Feb 25 21:56:53 master systemd: Stopped kubelet: The Kubernetes Node Agent.  
Feb 25 21:56:53 master systemd: Started kubelet: The Kubernetes Node Agent.  
Feb 25 21:56:53 master kubelet: F0225 21:56:53.242340   33085 server.go:189\] failed to load Kubelet config file /var/lib/kubelet/config.yaml, error failed to read kubelet config file "/var/lib/kubelet/config.yaml", error: open /var/lib/kubelet/config.yaml: no such file or directory  
Feb 25 21:56:53 master systemd: kubelet.service: main process exited, code=exited, status=255/n/a  
Feb 25 21:56:53 master systemd: Unit kubelet.service entered failed state.  
Feb 25 21:56:53 master systemd: kubelet.service failed

错误二：  
\[root@master ~\]\# docker pull mirrorgooglecontainers/kube-apiserver-amd64:v1.13.3  
Error response from daemon: Get https://registry-1.docker.io/v2/: proxyconnect tcp: dial tcp 172.96.236.117:10080: connect: connection refused  
解决：  
去掉代理

问题三  
Feb 25 22:39:53 master kubelet: W0225 22:39:53.428422    3123 cni.go:203\] Unable to update cni config: No networks found in /etc/cni/net.d  
Feb 25 22:39:53 master kubelet: E0225 22:39:53.428599    3123 kubelet.go:2192\] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized  
这个是flannel或者calico的cni配置文件还没生成  
生成之后就好了  
\[root@master ~\]\# ll /etc/cni/net.d/  
total 4  
\-rw-r--r--. 1 root root 267 Feb 25 22:51 10-flannel.conflist  
   
问题四  
docker: Error response from daemon: OCI runtime create failed: container\_linux.go:344: starting

CentOS 7升级新版的Linux内核  
添加 ELRepo仓库  
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org  
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm

启用仓库后，列出可用的kernel.related包  
yum --disablerepo="\*" --enablerepo="elrepo-kernel" list available

接下来安装最新的稳定版内核  
yum --enablerepo=elrepo-kernel install kernel-ml

设置默认的启动内核  
根据/boot/目录内的文件，自动创建GRUB内核配置开机选单  
grub2-mkconfig -o /boot/grub2/grub.cfg

查看可选的GRUB内核配置开机选单  
awk -F\\' '$1=="menuentry " \{print i++ " : " $2\}' /etc/grub2.cfg

通过命令指定默认的内核  
grub2-set-default 0

编辑/etc/default/grub文件，指定默认运行的内核版本。（0代表第一项）  
GRUB\_DEFAULT=0

更换内核之后启动，恢复正常

问题五  
\[root@node02 ~\]\# kubeadm join 192.168.6.100:6443 --token 2wh7mm.9zd1w12wyuqsdm7i --discovery-token-ca-cert-hash sha256:d0864f7935eff8a635f134e767c85b1a99629d3bc13508d3fc1c586e8a7f55b4  
\[preflight\] Running pre-flight checks  
    \[WARNING SystemVerification\]: this Docker version is not on the list of validated versions: 18.09.2. Latest validated version: 18.06  
\[discovery\] Trying to connect to API Server "192.168.6.100:6443"  
\[discovery\] Created cluster-info discovery client, requesting info from "https://192.168.6.100:6443"  
\[discovery\] Failed to connect to API Server "192.168.6.100:6443": token id "2wh7mm" is invalid for this cluster or it has expired. Use "kubeadm token create" on the master node to creating a new valid token

token过期导致  
kubeadm reset  
使用命令查看  
\[root@master ~\]\# kubeadm token list  
TOKEN     TTL       EXPIRES   USAGES    DESCRIPTION   EXTRA GROUPS  
这里为空  
重新创建一个  
\[root@master ~\]\# kubeadm token create  
o6vu26.dlq1knjxwqq93aht  
\[root@master ~\]\# kubeadm token list  
TOKEN                     TTL       EXPIRES                     USAGES                   DESCRIPTION   EXTRA GROUPS  
o6vu26.dlq1knjxwqq93aht   23h       2019-02-27T23:40:25+08:00   authentication,signing   <none>        system:bootstrappers:kubeadm:default-node-token

群名称：k8s学习群   群   号：153144292

[RESTFul]: https://www.centos.bz/tag/restful/