安装minikube
minikube介绍
minikube是kubernetes的简化版本，可以在本地运行单节点kubernetes集群，适合学习kubernetes使用。但minikube是一个没有高可用的单节点服务，不能启动生产集群。
虚拟机设置
安装之前需要开启虚拟化功能。这里是在vmvare虚拟机中安装。开启步骤如下图：
单击VMware虚拟机列表中的虚拟机进入虚拟机界面，依次点击虚拟机设置→处理器→虚拟化选项（需在虚拟机关机状态下完成）
虚拟机设置.png
安装VirtualBox
官网下载地址：https://www.virtualbox.org/wiki/Linux_Downloads
或者直接在虚拟机上执行wget https://download.virtualbox.org/virtualbox/6.1.12/VirtualBox-6.1-6.1.12_139181_el7-1.x86_64.rpm
或者通过官方yum源的方式安装，repo文件内容如下：
[virtualbox]
name=Oracle Linux / RHEL / CentOS-$releasever / $basearch - VirtualBox
baseurl=http://download.virtualbox.org/virtualbox/rpm/el/$releasever/$basearch
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://www.virtualbox.org/download/oracle_vbox.asc
如果使用官方yum源安装，则需要更新yum源安装。
yum clean all && yum makecache
yum install VirtualBox-6.1
由于网络原因，我通过下载rpm包方式安装。安装时报错缺少很多依赖，然后直接yum安装rpm包：
rpm -ivh VirtualBox-6.1-6.1.12_139181_el7-1.x86_64.rpm
warning: VirtualBox-6.1-6.1.12_139181_el7-1.x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 98ab5139: NOKEY
error: Failed dependencies:
libGL.so.1()(64bit) is needed by VirtualBox-6.1-6.1.12_139181_el7-1.x86_64
libICE.so.6()(64bit) is needed by VirtualBox-6.1-6.1.12_139181_el7-1.x86_64
libSDL-1.2.so.0()(64bit) is needed by VirtualBox-6.1-6.1.12_139181_el7-1.x86_64
libSM.so.6()(64bit) is needed by VirtualBox-6.1-6.1.12_139181_el7-1.x86_64
……(省略)
yum install VirtualBox-6.1-6.1.12_139181_el7-1.x86_64.rpm
……(省略)
Complete!
安装minikuber
下载地址：https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
如果谷歌地址下载失败，可以从阿里云的地址下载http://kubernetes.oss-cn-hangzhou.aliyuncs.com/minikube/releases/v1.4.0/minikube-linux-amd64
curl -O http://kubernetes.oss-cn-hangzhou.aliyuncs.com/minikube/releases/v1.4.0/minikube-linux-amd64
chmod +x minikube
mv minikube /usr/local/bin/
下载kubectl
curl -O http://kubernetes.oss-cn-hangzhou.aliyuncs.com/minikube/releases/v1.16.0/bin/windows/amd64/kubectl
chmod +x kubectl
mv kubectl /usr/local/bin/
创建集群
minikube默认给VM分配2G内存，如有必要可用以下命令调整内存。示例中将内存调到4G。minikube config set memory 4096
# minikube start
* minikube v1.4.0 on Centos 7.5.1804
* The "virtualbox" driver should not be used with root privileges.
* If you are running minikube within a VM, consider using --vm-driver=none:
* https://minikube.sigs.k8s.io/docs/reference/drivers/none/
这个报错提示，virtualbox不能被root用户启动，于是切换到普通用户
X Unable to start VM
* Error: [VBOX_DRV_NOT_LOADED] create: precreate: We support Virtualbox starting with version 5. Your VirtualBox install is "WARNING: The vboxdrv kernel module is not loaded. Either there is no module\n available for the current kernel (3.10.0-862.el7.x86_64) or it failed to\n load. Please recompile the kernel module and install it by\n\n sudo /sbin/vboxconfig\n\n You will not be able to start VMs until this problem is fixed.\n6.1.12r139181". Please upgrade at https://www.virtualbox.org
* Suggestion: Reinstall VirtualBox and reboot. Alternatively, try the kvm2 driver: https://minikube.sigs.k8s.io/docs/reference/drivers/kvm2/
依然报错。查看报错原因，当前内核(3.10.0-862.el7.x86_64)版本不支持，于是更新内核版本：
yum -y update
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
yum --disablerepo="*" --enablerepo="elrepo-kernel" list available #查看版本
yum --enablerepo=elrepo-kernel install kernel-ml #安装新版本内核
#设置grub2，内核安装好后要设置为默认启动项才会生效
awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg #查看已安装版本
0 : CentOS Linux (5.8.4-1.el7.elrepo.x86_64) 7 (Core)
1 : CentOS Linux (3.10.0-1127.19.1.el7.x86_64) 7 (Core)
2 : CentOS Linux (3.10.0-862.el7.x86_64) 7 (Core)
3 : CentOS Linux (0-rescue-04e78dda12d64388a7529320c6318965) 7 (Core)
#可以看到有4个内核版本。设置0为默认启动
grub2-set-default 0
#重启验证
uname -r
#加载vbox内核
rcvboxdrv setup
结果还是报错，经查需要安装kernel header文件（更新内核的操作是没必要的），命令：
yum install kernel-devel
还要记得用命令grub2-set-default 0把内核替换回去。
$ minikube start
* minikube v1.4.0 on Centos 7.8.2003
* Using image repository registry.cn-hangzhou.aliyuncs.com/google_containers
* Creating virtualbox VM (CPUs=2, Memory=2000MB, Disk=20000MB) ...
* Preparing Kubernetes v1.16.0 on Docker 18.09.9 ...
* Downloading kubeadm v1.16.0
* Downloading kubelet v1.16.0
* Pulling images ...
* Launching Kubernetes ...
* Waiting for: apiserver proxy etcd scheduler controller dns
* Done! kubectl is now configured to use "minikube"
启动成功，用命令minikube dashboard可以打开控制台。但是产生了报错
sudoers file. This incident will be reported.
[operator@localhost ~]$ minikube dashboard
* Verifying dashboard health ...
* Launching proxy ...
*
X kubectl proxy: proxy start: fork/exec /usr/local/bin/kubectl: exec format error
*
* Sorry that minikube crashed. If this was unexpected, we would love to hear from you:
- https://github.com/kubernetes/minikube/issues/new/choose
用命令开启控制台，依然报错：
# kubectl proxy --address='0.0.0.0' --accept-hosts='^*&'
/usr/local/bin/kubectl: line 1: syntax error near unexpected token `newline'
/usr/local/bin/kubectl: line 1: `<?xml version="1.0" encoding="UTF-8"?>'
居然报这个命令的语法错误，查看/usr/local/bin/kubectl文件：
<?xml version="1.0" encoding="UTF-8"?>
<Error>
<Code>NoSuchKey</Code>
<Message>The specified key does not exist.</Message>
<RequestId>5F476947E4499630362835B9</RequestId>
<HostId>kubernetes.oss-cn-hangzhou.aliyuncs.com</HostId>
<Key>minikube/releases/v1.16.0/bin/windows/amd64/kubectl</Key>
</Error>
诶，发现问题了，这个文件居然是个xml文件。这不是个命令吗，不是二进制文件也应该是个shell文件呀，为什么是xml呢。所以应该是文件下载错了，于是又找到正确的链接https://kubernetes.oss-cn-hangzhou.aliyuncs.com/kubernetes-release/release/v1.16.0/bin/linux/amd64/kubectl下载后重复之前的赋权、移动到/usr/local/bin/，再次启动控制台
$ minikube dashboard
* Verifying dashboard health ...
* Launching proxy ...
* Verifying proxy health ...
* Opening http://127.0.0.1:35534/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/ in your default browser...
X failed to open browser: exec: "xdg-open": executable file not found in $PATH
报错是说当前虚拟机没有图形化界面，不用处理。在本机浏览器访问那个地址，把IP替换成虚拟机IP，页面打不开。通过netstat命令发现35534端口监听在127.0.0.1上，并没有监听在0.0.0.0上。
$ netstat -lntp
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:35534 0.0.0.0:* LISTEN 3000/kubectl
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN -
tcp 0 0 192.168.122.1:53 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:953 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:35453 0.0.0.0:* LISTEN -
tcp6 0 0 :::111 :::* LISTEN -
tcp6 0 0 ::1:53 :::* LISTEN -
tcp6 0 0 :::22 :::* LISTEN -
tcp6 0 0 ::1:25 :::* LISTEN -
tcp6 0 0 ::1:953 :::* LISTEN -
将端口绑定在0.0.0.0:8001上：kubectl proxy --address=0.0.0.0 --accept-hosts="^*$"
然后可以通过http://IP:8001/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/#/overview?namespace=default访问控制台。
控制台.png
minikube常用操作
$ minikube version #查看版本
minikube version: v1.4.0
commit: b4e86486b6f529c2de808260556caa75ec6330cf
$ minikube status #查看状态
host: Running
kubelet: Running
apiserver: Running
kubectl: Correctly Configured: pointing to minikube-vm at 192.168.99.100
$ minikube start #启动一个kubernetes
* minikube v1.4.0 on Centos 7.8.2003
* Using image repository registry.cn-hangzhou.aliyuncs.com/google_containers
* Tip: Use 'minikube start -p <name>' to create a new cluster, or 'minikube delete' to delete this one.
* Using the running virtualbox "minikube" VM ...
* Waiting for the host to be provisioned ...
* Preparing Kubernetes v1.16.0 on Docker 18.09.9 ...
* Relaunching Kubernetes using kubeadm ...
* Waiting for: apiserver proxy etcd scheduler controller dns
* Done! kubectl is now configured to use "minikube"
#其他命令
$ minikube start --kubernetes-version v1.7.3 #指定版本启动kubernetes
$ minikube stop #关闭一个kubenates
$ minikube ip #查看内部虚拟机启动的IP
$ minikube ssh #进入虚机所构建的集群内部
$ minikube logs #查看运行log
$ minikube addons list #查看addons的列表
$ minikube delete #关闭集群并删除minikube虚拟机，不保留任何虚机数据或状态，但~/.minikube目录会存在缓存文件。
$ minikube dashboard #启动Kubernetes仪表盘
