Kubernetes 学习笔记 001
2020-02-13 本文已影响0人
chengchaos
Kubernetes
Kubernates 的概念
Namespace
Kubernetes 使用 namespace 来划分成多个虚拟集群，用以供不同的团队或业务群组使用，进行资源隔离等。
创建新 namespace 的命令：
kubectl create namespace chengchaos
Pod
Pod 是 kubernetes 的最小调度单元，可以看作应用服务的逻辑宿主机，通常可以这样理解：部署几个实例，就是部署几个 Pod。
Replication Controller
Pod 的控制器，用于监控指定条件 Pod 的实例状态，并维持其健康个数为指定的副本数量。其主要功能包括：确保 Pod实例数量、确保 Pod 健康、弹性伸缩、滚动升级。
Service
Service 为一组提供相同服务的 Pod 提供对外访问，具备对 Pod 的服务返现、路由的能力。
Label
Label 用来关联 Pod 和 Service，每个 Pod 可以定义 Label，然后 Service 可以通过 Label 去选择服务哪些 Pod。
Deployment
Repllication Controller 的升级版，对 Deployment 进行了更新、展示及控制，可以查看升级的纤细进度及状态，对每次 Deployment 进行版本管理，方便回滚，也可以对升级行为进行暂停和继续等。
Minikube
Minikube 是 Kubernetes 提供的
文档地址：
https://kubernetes.io/docs/tasks/tools/install-minikube/
安装 Minikube
- 安装 Docker
参考: https://docs.docker.com/install/linux/docker-ce/centos/
$ sudo yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-engine
$ sudo yum install -y yum-utils \
device-mapper-persistent-data \
lvm2
$ sudo yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
$ sudo yum install docker-ce docker-ce-cli containerd.io
$ sudo systemctl start docker
$ sudo docker run hello-world
- 安装 kubectl
参考: https://kubernetes.io/docs/tasks/tools/install-kubectl/#install-kubectl-on-linux
$ curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl
$ chmod +x ./kubectl
$ sudo mv ./kubectl /usr/local/bin/kubectl
$ kubectl version --client
Client Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.3", GitCommit:"06ad960bfd03b39c8310aaf92d1e7c12ce618213", GitTreeState:"clean", BuildDate:"2020-02-11T18:14:22Z", GoVersion:"go1.13.6", Compiler:"gc", Platform:"linux/amd64"}
- 安装 Minikube
参考: https://kubernetes.io/docs/tasks/tools/install-minikube/
$ curl -Lo minikube https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 \
&& chmod +x minikube
$ sudo mkdir -p /usr/local/bin/
$ sudo install minikube /usr/local/bin/
$ minikube status
E0213 16:27:33.329391 10179 status.go:98] The "minikube" cluster does not exist!
host: Nonexistent
kubelet: Nonexistent
apiserver: Nonexistent
kubeconfig: Nonexistent
- 安装 VirtualBox
$ sudo -i
# cd /etc/yum.repos.d/
# touch virtualbox.repo
# vim virtualbox.repo
virtualbox.repo 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
安装 VirtualBox :
# written
[root@bogon yum.repos.d]# yum search VirtualBox
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.zju.edu.cn
* extras: mirror.lzu.edu.cn
* updates: mirrors.zju.edu.cn
virtualbox/7/x86_64/signature | 181 B 00:00
Retrieving key from https://www.virtualbox.org/download/oracle_vbox.asc
Importing GPG key 0x98AB5139:
Userid : "Oracle Corporation (VirtualBox archive signing key) <info@virtualbox.org>"
Fingerprint: 7b0f ab3a 13b9 0743 5925 d9c9 5442 2a4b 98ab 5139
From : https://www.virtualbox.org/download/oracle_vbox.asc
Is this ok [y/N]: y
virtualbox/7/x86_64/signature | 2.9 kB 00:04 !!!
virtualbox/7/x86_64/primary_db | 146 kB 00:01
=========================== N/S matched: VirtualBox ============================
VirtualBox-4.3.x86_64 : Oracle VM VirtualBox
VirtualBox-5.0.x86_64 : Oracle VM VirtualBox
VirtualBox-5.1.x86_64 : Oracle VM VirtualBox
VirtualBox-5.2.x86_64 : Oracle VM VirtualBox
VirtualBox-6.0.x86_64 : Oracle VM VirtualBox
VirtualBox-6.1.x86_64 : Oracle VM VirtualBox
Name and summary matches only, use "search all" for everything.
# yum -y install VirtualBox-6.1
# exit
- 启动 Minikube
$ minikube start --vm-driver=virtualbox
* minikube v1.7.2 on Centos 7.7.1908
* Using the virtualbox driver based on user configuration
* Downloading VM boot image ...
$
* minikube v1.7.2 on Centos 7.7.1908
* Using the virtualbox driver based on user configuration
* Creating virtualbox VM (CPUs=2, Memory=2000MB, Disk=20000MB) ...
*
X Unable to start VM. Please investigate and run 'minikube delete' if possible
* 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 (3.10.0-1062.9.1.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.\n5.1.38r122592". 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/
* Related issues:
- https://github.com/kubernetes/minikube/issues/4043
- https://github.com/kubernetes/minikube/issues/4711
$ sudo /sbin/vboxconfig
vboxdrv.sh: Stopping VirtualBox services.
vboxdrv.sh: Building VirtualBox kernel modules.
This system is not currently set up to build kernel modules (system extensions).
Running the following commands should set the system up correctly:
yum install gcc make
yum install kernel-devel-3.10.0-1062.9.1.el7.x86_64
(The last command may fail if your system is not fully updated.)
yum install kernel-devel
vboxdrv.sh: failed: Look at /var/log/vbox-install.log to find out what went wrong.
This system is not currently set up to build kernel modules (system extensions).
Running the following commands should set the system up correctly:
yum install gcc make
yum install kernel-devel-3.10.0-1062.9.1.el7.x86_64
(The last command may fail if your system is not fully updated.)
yum install kernel-devel
There were problems setting up VirtualBox. To re-start the set-up process, run
/sbin/vboxconfig
as root
$ sudo -i
# /sbin/vboxconfig
vboxdrv.sh: Stopping VirtualBox services.
vboxdrv.sh: Building VirtualBox kernel modules.
