1. 介紹
Minikube是Kubernetes社區維護的單機版的Kubernetes集群工具，幫助Kubernetes新手和開發者快速建立本地的Kubernetes集群,降低Kubernetes學習成本。
在Kubernetes文檔中也首推開發者使用Minikube進行學習使用，見：https://kubernetes.io/zh/docs/tutorials/hello-minikube/
Minikube官網鏈接： https://minikube.sigs.k8s.io
以下是在本地Linux虛擬機中搭建成功的結果示例：
[landscape@MiWiFi-R4CM-srv ~]$ minikube start
* Centos 7.8.2003 上的 minikube v1.15.1
* 根據現有的配置文件使用 docker 驅動程序
* Starting control plane node minikube in cluster minikube
* Updating the running docker "minikube" container ...
* 正在 Docker 20.10.0 中准備 Kubernetes v1.19.4…
* Verifying Kubernetes components...
* Enabled addons: storage-provisioner, default-storageclass, dashboard
* Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default
[landscape@MiWiFi-R4CM-srv ~]$ minikube status
minikube
type: Control Plane
host: Running
kubelet: Running
apiserver: Running
kubeconfig: Configured
[landscape@MiWiFi-R4CM-srv ~]$ docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e4acce8ab8c3 kicbase/stable:v0.0.15-snapshot4 "/usr/local/bin/entr…" 5 weeks ago Up 10 hours 127.0.0.1:32771->22/tcp, 127.0.0.1:32770->2376/tcp, 127.0.0.1:32769->5000/tcp, 127.0.0.1:32768->8443/tcp minikube
[landscape@MiWiFi-R4CM-srv ~]$ minikube ssh
docker@minikube:~$ docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c38e76753066 bad58561c4be "/storage-provisioner" 5 hours ago Up 5 hours k8s_storage-provisioner_storage-provisioner_kube-system_41b54bd4-c655-4f3d-8e65-0945bf564971_15
a697f54873d6 503bc4b7440b "/dashboard --insecu…" 10 hours ago Up 10 hours k8s_kubernetes-dashboard_kubernetes-dashboard-6f9cb85d88-6s4v9_kubernetes-dashboard_0c142bb5-a1ed-4f78-a56d-e408a1ce4120_8
150b34be990b 86262685d9ab "/metrics-sidecar" 10 hours ago Up 10 hours k8s_dashboard-metrics-scraper_dashboard-metrics-scraper-c85578d8-k7vdm_kubernetes-dashboard_1dd96b8e-c9ca-4e25-b632-0b187b85ca51_4
f9cf094c99f0 bfe3a36ebd25 "/coredns -conf /etc…" 10 hours ago Up 10 hours k8s_coredns_coredns-6c76c8bb89-gb8rp_kube-system_6f72f157-73da-4618-b882-b9a2cddc6f46_8
aeb847fb4718 635b36f4d89f "/usr/local/bin/kube…" 10 hours ago Up 10 hours k8s_kube-proxy_kube-proxy-vm84w_kube-system_4e157482-6fee-4d5c-9e8c-7848666bfea2_7
006b63a03302 4830ab618586 "kube-controller-man…" 10 hours ago Up 10 hours k8s_kube-controller-manager_kube-controller-manager-minikube_kube-system_be338aa45050ec7206c766bab91becdb_8
5f8a8157b70a 14cd22f7abe7 "kube-scheduler --au…" 10 hours ago Up 10 hours k8s_kube-scheduler_kube-scheduler-minikube_kube-system_bfdfba5e160e5615ef897a84299c8df5_7
6c17b84fe3b0 b15c6247777d "kube-apiserver --ad…" 10 hours ago Up 10 hours k8s_kube-apiserver_kube-apiserver-minikube_kube-system_84fbf273d9d4bc25831a46f437b7344c_8
62509564babb 0369cf4303ff "etcd --advertise-cl…" 10 hours ago Up 10 hours k8s_etcd_etcd-minikube_kube-system_44e0bd5176f5542a3e8d77b000b60c76_8
雖然Minikube官方文檔很完善，但是還是會讓第一次使用的人摸不着頭腦。希望這篇簡單的文章可以幫助你繞過彎路初窺Kubernetes的真容。
如果文中出現錯誤或者有更好的方案，歡迎評論交流。
2. 安裝
本文默認安裝環境為：
- Cent OS 7.X+
- Docker 19.0+
其他版本或環境也可以稍作參考，沒有安裝Docker可以按照Docker官方文檔的步驟安裝Docker：https://docs.docker.com/engine/install/
2.1 Minikube
首先從官網選擇合適的版本下載Minikube，地址：https://minikube.sigs.k8s.io/docs/start/
這里建議用X雷或者其他工具下載
上傳到服務器，我這里選擇了二進制文件進行安裝，所以按照文檔執行命令：sudo install minikube-linux-amd64 /usr/local/bin/minikube
[landscape@localhost ~]$ ls
minikube-linux-amd64
[landscape@localhost ~]$ sudo install minikube-linux-amd64 /usr/local/bin/minikube
[landscape@localhost ~]$ minikube start
* Centos 7.8.2003 上的 minikube v1.17.0
* minikube 1.17.1 is available! Download it: https://github.com/kubernetes/minikube/releases/tag/v1.17.1
* To disable this notice, run: 'minikube config set WantUpdateNotification false'
* 根據現有的配置文件使用 docker 驅動程序
* Starting control plane node minikube in cluster minikube
* Pulling base image ...
到這里繼續按照官方文檔的步驟直接執行minikube start大概率是沒用的，minikube會從谷歌鏡像倉庫下載所需鏡像，可能是用法網絡等原因，按照阿里雲社區這篇文檔的步驟進行依舊無法使用：https://developer.aliyun.com/article/221687。
然后一直卡住,最終下載以失敗告終，如下：
[landscape@localhost ~]$ ./minikube-linux-amd64-ali start --image-mirror-country cn --registry-mirror=https://registry.docker-cn.com
* Centos 7.8.2003 上的 minikube v1.16.0
* 根據現有的配置文件使用 docker 驅動程序
* Starting control plane node minikube in cluster minikube
* Pulling base image ...
E0130 20:58:57.870751 3153 cache.go:180] Error downloading kic artifacts: failed to download kic base image or any fallback image
* Creating docker container (CPUs=2, Memory=2200MB) ...
! StartHost failed, but will try again: creating host: create: creating: setting up container node: preparing volume for minikube container: docker run --rm --entrypoint /usr/bin/test -v minikube:/var kicbase/stable:v0.0.17 -d /var/lib: exit status 125
stdout:
stderr:
Unable to find image 'kicbase/stable:v0.0.17' locally
docker: Error response from daemon: Head https://registry-1.docker.io/v2/kicbase/stable/manifests/v0.0.17: Get https://auth.docker.io/token?scope=repository%3Akicbase%2Fstable%3Apull&service=registry.docker.io: net/http: TLS handshake timeout.
See 'docker run --help'.
* docker "minikube" container is missing, will recreate.
* Creating docker container (CPUs=2, Memory=2200MB) ...
我們從錯誤信息中得知minikube拉取的基礎鏡像是 kicbase/stable:v0.0.17，這里可以在DockerHub中找到鏡像 ，如下：
嘗試手動拉取鏡像：
[landscape@localhost ~]$ docker pull kicbase/stable:v0.0.17
v0.0.17: Pulling from kicbase/stable
da7391352a9b: Pull complete
14428a6d4bcd: Pull complete
2c2d948710f2: Pull complete
a068cd99c676: Pull complete
086636b22e9d: Pull complete
5221d3fd465c: Pull complete
8a2738df9ade: Pull complete
74fc054d5085: Downloading [============================> ] 10.84MB/19.17MB
20228527694f: Download complete
a7823b5983e9: Downloading [==> ] 5.901MB/130.4MB
a036a37c5c11: Downloading [==========================================> ] 36.82MB/43.48MB
bb15b50b0a94: Waiting
a596876de093: Waiting
0e301f5a0ff7: Waiting
9e29a8a5c096: Waiting
445dc96e3be9: Waiting
f41b1d751d1d: Waiting
cdabbc900ca4: Waiting
網絡不好的可以嘗試更換版本、開啟魔法上網工具，實在不行可以嘗試一下其他的備用鏡像：
然后使用minikube參數指定你下載的鏡像即可啟動minikube
[landscape@localhost ~]$ minikube start --base-image="kicbase/stable:v0.0.15-snapshot4" --image-repository='registry.cn-hangzhou.aliyuncs.com/google_containers'
* Centos 7.8.2003 上的 minikube v1.17.0
* 自動選擇 docker 驅動
* 正在使用鏡像存儲庫 registry.cn-hangzhou.aliyuncs.com/google_containers
* Starting control plane node minikube in cluster minikube
* Creating docker container (CPUs=2, Memory=2200MB) ...
> kubectl.sha256: 64 B / 64 B [--------------------------] 100.00% ? p/s 0s
> kubeadm.sha256: 64 B / 64 B [--------------------------] 100.00% ? p/s 0s
- Generating certificates and keys ...
- Booting up control plane ...
- Configuring RBAC rules ...
* Verifying Kubernetes components...
* Enabled addons: storage-provisioner, default-storageclass
* Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default
2.2 kubectl(可選)
接下來安裝kubectl管理Kubernetes集群，可以直接在Kubernetes官網找到安裝命令執行
curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl
也將版本號替換到鏈接中用X雷或者其他工具下載，例如我這里下載的版本是v1.20.2,所以直接下載 https://dl.k8s.io/release/v1.20.2/bin/linux/amd64/kubectl 即可。
3. 啟動示例
寫入一個簡單的Deployment示例：
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: mynginx
image: nginx:1.19.6
ports:
- containerPort: 80
創建Deployment：
[landscape@localhost minikube]$ kubectl create -f nginx-deploy.yaml
deployment.apps/nginx-deployment created
[landscape@localhost minikube]$ kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deployment-bd5567f5b 3 3 0 11s
[landscape@localhost minikube]$ kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-deployment-bd5567f5b-ctqjb 0/1 ContainerCreating 0 15s
nginx-deployment-bd5567f5b-pzntl 0/1 ContainerCreating 0 15s
nginx-deployment-bd5567f5b-tp8vc 0/1 ContainerCreating 0 15s
這里是一個小坑，Minikube的鏡像運行在Docker容器里沒有任何配置，即會從官方registry拉取鏡像，所以如果像下面一樣創建失敗了(ImagePullBackOff)也不奇怪
[landscape@localhost minikube]$ kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-deployment-bd5567f5b-ctqjb 0/1 ContainerCreating 0 11m
nginx-deployment-bd5567f5b-pzntl 0/1 ImagePullBackOff 0 11m
nginx-deployment-bd5567f5b-tp8vc 0/1 ContainerCreating 0 11m
所以像配置外部Docker一樣配置容器內的鏡像加速即可，使用minikube ssh進入容器，然后創建或修改/etc/docker/daemon.json文件，如果不了解的同學按照 阿里雲 官方鏡像加速這篇文章操作就行。
minikube ssh
sudo chmod 777 /etc/docker/ && sudo echo '{"registry-mirrors": ["https://XXXXXXXX.mirror.aliyuncs.com"]}' > /etc/docker/daemon.json
重啟minikube，stop + start ，直接start雖然顯示update但是沒什么用
[landscape@localhost minikube]$ minikube stop
* Stopping node "minikube" ...
* 正在通過 SSH 關閉“minikube”…
* 1 nodes stopped.
[landscape@localhost minikube]$ minikube start
* Centos 7.8.2003 上的 minikube v1.17.0
* 根據現有的配置文件使用 docker 驅動程序
* Starting control plane node minikube in cluster minikube
* Restarting existing docker container for "minikube" ...
! This container is having trouble accessing https://registry.cn-hangzhou.aliyuncs.com/google_containers
* To pull new external images, you may need to configure a proxy: https://minikube.sigs.k8s.io/docs/reference/networking/proxy/
* 正在 Docker 20.10.0 中准備 Kubernetes v1.20.2…
* Verifying Kubernetes components...
* Enabled addons: default-storageclass, storage-provisioner
* Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default
[landscape@localhost minikube]$ kubectl delete deploy nginx-deployment
deployment.apps "nginx-deployment" deleted
[landscape@localhost minikube]$ kubectl create -f nginx-deploy.yaml
deployment.apps/nginx-deployment created
[landscape@localhost minikube]$ kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deployment-5599fc6777 3 3 0 4s
[landscape@localhost minikube]$ kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-deployment-5599fc6777-7fmvp 1/1 Running 0 34s
nginx-deployment-5599fc6777-9t5k5 1/1 Running 0 34s
nginx-deployment-5599fc6777-tr49g 1/1 Running 0 34s
nginx-deployment-bd5567f5b-7rczv 0/1 Terminating 0 2m22s
nginx-deployment-bd5567f5b-pjcsl 0/1 Terminating 0 2m22s
nginx-deployment-bd5567f5b-xpsjb 0/1 Terminating 0 2m22s
pod成功運行，開始有趣的Kubernetes學習之旅吧👌~