Kubernetes容器化工具Kind實踐部署Kubernetes v1.18.x 版本, 釋出WordPress和MySQL
阿新 • • 發佈:2020-07-14
## Kind 介紹
[Kind](https://kind.sigs.k8s.io/)是Kubernetes In Docker的縮寫,顧名思義是使用Docker容器作為Node並將Kubernetes部署至其中的一個工具。官方文件中也把Kind作為一種本地叢集搭建的工具進行推薦。預設情況下,Kind會先下載kindest/node映象,該映象包含kubernetes的主要元件,當映象節點準備好時,Kind使用kubeadm進行叢集的建立,內部使用containerd跑元件容器。最終,Kind只是為了方便測試kubernetes叢集的,且不可用於生產環境。
![](https://raw.githubusercontent.com/PassZhang/passzhang.github.io/images-picgo/20200714154918.png)
## 部署Kind
Kind使用Golang進行開發,在倉庫的Release頁面,已經上傳了構建好的二進位制,支援多種作業系統,可直接按需下載進行使用。
```
wget -O /usr/local/bin/kind https://github.com/kubernetes-sigs/kind/releases/download/v0.8.1/kind-linux-amd64 && chmod +x /usr/local/bin/kind
# kind v0.8.1版本支援最新kubernetes v1.18.2叢集
```
**安裝docker**
```
yum-config-manager --add-repo https://mirrors.ustc.edu.cn/docker-ce/linux/centos/docker-ce.repo
sed -i 's#download.docker.com#mirrors.ustc.edu.cn/docker-ce#g' /etc/yum.repos.d/docker-ce.repo
yum install -y docker-ce
```
**部署kubectl**
```
wget -O /usr/local/bin/kubctl https://storage.googleapis.com/kubernetes-release/release/v1.18.5/bin/linux/amd64/kubectl
chmod +x /usr/local/bin/kubectl
```
## 建立kind單叢集
### 使用kind命令建立
**使用`kind create` 建立叢集,預設是單節點叢集。**
```
# kind create cluster --name test
Creating cluster "test" ...
✓ Ensuring node image (kindest/node:v1.18.2)
✓ Preparing nodes
✓ Creating kubeadm config
✓ Starting control-plane ️
✓ Installing CNI
✓ Installing StorageClass
Cluster creation complete. You can now use the cluster with:
export KUBECONFIG="$(kind get kubeconfig-path --name="test")"
kubectl cluster-info
```
**在docker環境下,會啟動一個映象**
```
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2e0a5e15a4a0 kindest/node:v1.18.2 "/usr/local/bin/entr…" 14 minutes ago Up 14 minutes 45319/tcp, 127.0.0.1:45319->6443/tcp test-control-plane
```
**檢視叢集資訊**
```
export KUBECONFIG="$(kind get kubeconfig-path --name="test")"
echo 'export KUBECONFIG="$(kind get kubeconfig-path --name=test)"' >> /root/.bashrc
kubectl cluster-info
Kubernetes master is running at https://localhost:45319
KubeDNS is running at https://localhost:45319/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
kubectl get node -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
test-control-plane Ready master 16m v1.18.2 172.17.0.2 Ubuntu Disco Dingo (development branch) 3.10.0-693.el7.x86_64 containerd://1.2.6-0ubuntu1
kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-fb8b8dccf-6r58d 1/1 Running 0 17m
kube-system coredns-fb8b8dccf-bntk8 1/1 Running 0 17m
kube-system etcd-test-control-plane 1/1 Running 0 17m
kube-system ip-masq-agent-qww8n 1/1 Running 0 17m
kube-system kindnet-vbz6w 1/1 Running 0 17m
kube-system kube-apiserver-test-control-plane 1/1 Running 0 16m
kube-system kube-controller-manager-test-control-plane 1/1 Running 0 17m
kube-system kube-proxy-wf7dq 1/1 Running 0 17m
kube-system kube-scheduler-test-control-plane 1/1 Running 0 16m
```
**啟動nginx app**
```
kubectl run nginx --image nginx:1.17.0-alpine --restart=Never --port 80 --labels="app=nginx-test"
kubectl port-forward --address 0.0.0.0 pod/nginx 8080:80
curl localhost:8080
```
### **指定配置檔案建立**
```
# cat kube-config.yaml
kind: Cluster
apiVersion: kind.sigs.k8s.io/v1alpha3
kubeadmConfigPatches:
- |
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
metadata:
name: config
networking:
serviceSubnet: 10.0.0.0/16
imageRepository: registry.aliyuncs.com/google_containers
nodeRegistration:
kubeletExtraArgs:
pod-infra-container-image: registry.aliyuncs.com/google_containers/pause:3.1
- |
apiVersion: kubeadm.k8s.io/v1beta2
kind: InitConfiguration
metadata:
name: config
networking:
serviceSubnet: 10.0.0.0/16
imageRepository: registry.aliyuncs.com/google_containers
nodes: # 指定節點,預設是一個節點
- role: control-plane
# kind create cluster --name test2 --config kube-config.yaml
Creating cluster "test2" ...
✓ Ensuring node image (kindest/node:v1.18.2)
✓ Preparing nodes
✓ Creating kubeadm config
✓ Starting control-plane ️
✓ Installing CNI
✓ Installing StorageClass
Cluster creation complete. You can now use the cluster with:
export KUBECONFIG="$(kind get kubeconfig-path --name="test2")"
kubectl cluster-info
```
## 建立kind-ha叢集
只能通過配置檔案來宣告ha叢集配置
```
# cat kind-ha-config.yaml
kind: Cluster
apiVersion: kind.sigs.k8s.io/v1alpha3
kubeadmConfigPatches:
- |
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
metadata:
name: config
networking:
serviceSubnet: 10.0.0.0/16
imageRepository: registry.aliyuncs.com/google_containers
nodeRegistration:
kubeletExtraArgs:
pod-infra-container-image: registry.aliyuncs.com/google_containers/pause:3.1
- |
apiVersion: kubeadm.k8s.io/v1beta2
kind: InitConfiguration
metadata:
name: config
networking:
serviceSubnet: 10.0.0.0/16
imageRepository: registry.aliyuncs.com/google_containers
nodes: #主要修改這個位置,增加role,指定node節點,工作節點名稱必須為worker,master節點必須為control-plane
- role: control-plane
- role: control-plane
- role: control-plane
- role: worker
- role: worker
- role: worker
# kind create cluster --name test-ha --config kind-ha-config.yaml
Creating cluster "test-ha" ...
✓ Ensuring node image (kindest/node:v1.18.2)
✓ Preparing nodes
✓ Configuring the external load balancer ⚖️
✓ Creating kubeadm config
✓ Starting control-plane ️
✓ Installing CNI
✓ Installing StorageClass
✓ Joining more control-plane nodes
✓ Joining worker nodes
Cluster creation complete. You can now use the cluster with:
export KUBECONFIG="$(kind get kubeconfig-path --name="test3")"
kubectl cluster-info
# kubectl get nodes
NAME STATUS ROLES AGE VERSION
test3-control-plane Ready master 7m44s v1.18.2
test3-control-plane2 Ready master 4m59s v1.18.2
test3-control-plane3 Ready master 2m18s v1.15.0
test3-worker Ready 110s v1.15.0
test3-worker2 Ready 109s v1.15.0
test3-worker3 Ready 105s v1.15.0
```
## 常用操作
kind 是基於 docker 的,那麼我們再來看下 docker 資源,來驗證一下是否真的是基於 docker 的?
```
# 本機執行,就會提示有個docker容器正在執行,可以看到 docker 裡有一個 container,而 kind 建立的叢集就是基於這個 container 的,如果你直接刪掉了這個 container,通過 kind 建立的 k8s 叢集也會有問題
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2e0a5e15a4a0 kindest/node:v1.18.2 "/usr/local/bin/entr…" 14 minutes ago Up 14 minutes 45319/tcp, 127.0.0.1:45319->6443/tcp test-control-plane
```
再來看一下 network,執行 `docker network ls`,可以看到有一個名稱為 kind 的 network。
```
docker network ls
NETWORK ID NAME DRIVER SCOPE
94de31154cb7 bridge bridge local
0c31de104d44 host host local
a667b873436d kind bridge local
6083dbc308a4 none null local
```
我們可以進一步探究 kind-control-plane(就是上面的 docker container)
通過 `docker exec kind-control-plane crictl ps` 獲取這個容器內部的執行容器列表,這個容器內部通過 `crictl` 來操作容器,可以參考 https://github.com/kubernetes-sigs/cri-tools,crtctl 主要用來管理容器,命令使用和docker命令是一樣,可以通過 `docker exec kind-control-plane crictl help` 幫助檢視命令使用方法。
```
# master 節點
docker exec kind-ha-control-plane crictl ps
CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID
4b62cd954c86a ace0a8c17ba90 18 minutes ago Running kube-controller-manager 3 8f000bb1c20f3
90552a29c50d9 db10073a6f829 19 minutes ago Running local-path-provisioner 8 7e648bc7297b1
268f41443c426 a3099161e1375 19 minutes ago Running kube-scheduler 4 a64377f98d627
aa3fea2edc80d 67da37a9a360e 3 hours ago Running coredns 0 719884414c5f4
04c58978f5395 67da37a9a360e 3 hours ago Running coredns 0 da6e08629ac71
110429a5a873b 2186a1a396deb 3 hours ago Running kindnet-cni 0 5359903320ef9
1c125b02f6300 0d40868643c69 3 hours ago Running kube-proxy 0 9ba4d0a1fdd3d
0301cd4d26d9c 6ed75ad404bdd 3 hours ago Running kube-apiserver 0 4905e2b2a8a1a
435ee12a45bff 303ce5db0e90d 3 hours ago Running etcd 0 96f4e9190bede
# worker節點
docker exec kind-ha-worker crictl ps
CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID
5e82bf4756b6f bfba26ca350c1 21 minutes ago Running nginx 0 78d1324b8b1a1
ea02b20040341 0d40868643c69 3 hours ago Running kube-proxy 0 de6a57d0b7381
c2aa986df532f 2186a1a396deb 3 hours ago Running kindnet-cni 1 ebea7a329cfe0
```
**獲取 k8s 叢集所有資源示例**
```
kubectl get all --all-namespaces
```
**獲取叢集外部的config配置配置檔案**
```
kind get kubeconfig --name kind-ha
```
**獲取叢集內部的config配置配置檔案(一般獲取外部就夠用了)**
```
kind get kubeconfig --internal --name kind-ha
```
**刪除叢集(清理很方便)**
```
kind delete cluster --name test
```
**掛載檔案**
```
nodes:
- role: control-plane
extraMounts:
- containerPath: /etc/docker/daemon.json
hostPath: /etc/docker/daemon.json
readOnly: true
```
**暴露埠方法1**
```
nodes:
- role: control-plane
extraPortMappings:
- containerPort: 30080
hostPort: 30080
```
> 有時候我們想暴露svc的埠給外部訪問,因為kubernetes的節點是在docker容器中,所以還需要容器暴露svc的埠,外部才能通過宿主機訪問。
**暴露埠方法2**
```
# 使用埠轉發的方式
kubectl port-forward --address 0.0.0.0 pod/nginx 8080:80
```
**從私有倉庫下載映象**
```
docker exec test-drone-control-plane bash -c "sed -i '56a\ [plugins.cri.registry.mirrors.\"192.168.77.134:5000\"]' /etc/containerd/config.toml"
docker exec test-drone-control-plane bash -c "sed -i '57a\ endpoint = [\"http://192.168.77.134:5000\"]' /etc/containerd/config.toml"
docker exec test-drone-control-plane bash -c "cat /etc/containerd/config.toml"
docker exec test-drone-control-plane bash -c 'kill -s SIGHUP $(pgrep containerd)'
COPY
```
> 還可以通過掛載檔案的方式,掛載containerd的配置檔案
**重啟叢集**
```
docker stop test-drone-control-plane
docker start test-drone-control-plane
COPY
```
總之,kind可以很方便的在docker環境下建立測試叢集,而不汙染我們的宿主機,給我們測試提供了很大的便利。
## 示例:使用持久卷部署WordPress和MySQL
本教程向您展示如何使用Kind部署WordPress網站和MySQL資料庫。這兩個應用程式都使用PersistentVolumes和PersistentVolumeClaims來儲存資料。
[PersistentVolume](https://kubernetes.io/docs/concepts/storage/persistent-volumes/)(PV)是已經由管理員手動供應,或動態地使用由Kubernetes置備叢集中的一塊儲存的[StorageClass](https://kubernetes.io/docs/concepts/storage/storage-classes)。[PersistentVolumeClaim](https://kubernetes.io/docs/concepts/storage/persistent-volumes/#persistentvolumeclaims)(PVC)是由能夠由PV滿足使用者對於儲存的請求。PersistentVolumes和PersistentVolumeClaims與Pod生命週期無關,並通過重新啟動,重新計劃甚至刪除Pod來保留資料。
> **警告:**此部署不適合生產用例,因為它使用單例項WordPress和MySQL Pods。考慮使用[WordPress Helm Chart](https://github.com/kubernetes/charts/tree/master/stable/wordpress)在生產中部署WordPress。
> **注意:**本教程中提供的檔案使用的是GA Deployment API,並且特定於kubernetes 1.9和更高版本。如果您希望將本教程與Kubernetes的早期版本一起使用,請相應地更新API版本,或參考本教程的早期版本。
### 目標
- 建立PersistentVolumeClaims和PersistentVolumes
- 建立一個`kustomization.yaml`與
- Secret密碼配置
- MySQL資源配置
- WordPress資源配置
- 通過以下方式應用Kustomization目錄 `kubectl apply -k ./`
- 清理
### 在你開始之前
您需要具有Kubernetes叢集,並且必須將kubectl命令列工具配置為與叢集通訊。如果還沒有叢集,則可以使用[Minikube](https://kubernetes.io/docs/setup/learning-environment/minikube/)或者是Kind建立一個叢集,也 可以使用以下Kubernetes遊樂場之一:
- [katacoda](https://www.katacoda.com/courses/kubernetes/playground)
- [play-Kubernetes](http://labs.play-with-k8s.com/)
要檢查版本,請輸入`kubectl version`。此頁面上顯示的示例適用於`kubectl`1.14及更高版本,上面我們已經建立了kind-ha叢集,直接執行後面的步驟既可。
```
kubectl version
Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.5", GitCommit:"e6503f8d8f769ace2f338794c914a96fc335df0f", GitTreeState:"clean", BuildDate:"2020-06-26T03:47:41Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.2", GitCommit:"52c56ce7a8272c798dbc29846288d7cd9fbae032", GitTreeState:"clean", BuildDate:"2020-04-16T11:48:36Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
```
下載以下配置檔案:
1. [mysql-deployment.yaml](https://kubernetes.io/examples/application/wordpress/mysql-deployment.yaml)
2. [wordpress-deployment.yaml](https://kubernetes.io/examples/application/wordpress/wordpress-deployment.yaml)
### 建立PersistentVolumeClaims和PersistentVolumes
MySQL和Wordpress都需要一個PersistentVolume來儲存資料。他們的PersistentVolumeClaims將在部署步驟中建立。
許多叢集環境都安裝了預設的StorageClass。如果在PersistentVolumeClaim中未指定StorageClass,則使用群集的預設StorageClass。
建立PersistentVolumeClaim後,將根據StorageClass配置動態設定PersistentVolume。
```
# 檢視StorageClass
kubectl get sc
kubectl describe sc $(kubectl get sc |grep default|awk 'NR==2{print $1}')
```
> **警告:**在本地叢集中,預設的StorageClass使用`hostPath`配置程式。`hostPath`該卷僅適用於開發和測試。有了`hostPath`卷,您的資料`/tmp`將駐留在Pod排程到的節點上,並且不會在節點之間移動。如果Pod死亡並被排程到群集中的另一個節點,或者該節點被重新引導,則資料將丟失。
> **注意:**如果要啟動需要使用`hostPath`配置程式的群集,則`--enable-hostpath-provisioner`必須在`controller-manager`元件中設定該標誌。
> **注意:**如果您有一個在Kubernetes Engine上執行的Kubernetes叢集,請遵循[本指南](https://cloud.google.com/kubernetes-engine/docs/tutorials/persistent-disk)。
### 建立一個Secret密碼檔案kustomization.yaml
[secret](https://kubernetes.io/docs/concepts/configuration/secret/)是一個物件,其儲存了一塊如密碼或金鑰的敏感資料。從1.14開始,`kubectl`支援使用kustomization檔案管理Kubernetes物件。您可以通過中的生成器建立Secret `kustomization.yaml`。
`kustomization.yaml`從以下命令中新增一個Secret生成器。您將需要替換`YOUR_PASSWORD`為您要使用的密碼。
```shell
cat <./kustomization.yaml
secretGenerator:
- name: mysql-pass
literals:
- password=YOUR_PASSWORD
EOF
```
### 為MySQL和WordPress新增資源配置
以下清單描述了單例項MySQL部署。MySQL容器將PersistentVolume掛載在/ var / lib / mysql。在`MYSQL_ROOT_PASSWORD`環境變數設定從secret資料庫密碼。
[`application/wordpress/mysql-deployment.yaml`](https://raw.githubusercontent.com/kubernetes/website/master/content/en/examples/application/wordpress/mysql-deployment.yaml)
```
apiVersion: v1
kind: Service
metadata:
name: wordpress-mysql
labels:
app: wordpress
spec:
ports:
- port: 3306
selector:
app: wordpress
tier: mysql
clusterIP: None
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysql-pv-claim
labels:
app: wordpress
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 20Gi
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
name: wordpress-mysql
labels:
app: wordpress
spec:
selector:
matchLabels:
app: wordpress
tier: mysql
strategy:
type: Recreate
template:
metadata:
labels:
app: wordpress
tier: mysql
spec:
containers:
- image: mysql:5.6
name: mysql
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-pass
key: password
ports:
- containerPort: 3306
name: mysql
volumeMounts:
- name: mysql-persistent-storage
mountPath: /var/lib/mysql
volumes:
- name: mysql-persistent-storage
persistentVolumeClaim:
claimName: mysql-pv-claim
```
以下清單描述了單例項WordPress部署。WordPress容器將PersistentVolume安裝在`/var/www/html`用於網站資料檔案的位置。在`WORDPRESS_DB_HOST`環境變數設定上面定義的MySQL服務的名稱,WordPress會由服務訪問資料庫。在 `WORDPRESS_DB_PASSWORD`環境變數設定從生成的祕密kustomize資料庫密碼。
[`application/wordpress/wordpress-deployment.yaml`](https://raw.githubusercontent.com/kubernetes/website/master/content/en/examples/application/wordpress/wordpress-deployment.yaml)
```
application/wordpress/wordpress-deployment.yaml
apiVersion: v1
kind: Service
metadata:
name: wordpress
labels:
app: wordpress
spec:
ports:
- port: 80
selector:
app: wordpress
tier: frontend
type: LoadBalancer
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: wp-pv-claim
labels:
app: wordpress
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 20Gi
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
name: wordpress
labels:
app: wordpress
spec:
selector:
matchLabels:
app: wordpress
tier: frontend
strategy:
type: Recreate
template:
metadata:
labels:
app: wordpress
tier: frontend
spec:
containers:
- image: wordpress:4.8-apache
name: wordpress
env:
- name: WORDPRESS_DB_HOST
value: wordpress-mysql
- name: WORDPRESS_DB_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-pass
key: password
ports:
- containerPort: 80
name: wordpress
volumeMounts:
- name: wordpress-persistent-storage
mountPath: /var/www/html
volumes:
- name: wordpress-persistent-storage
persistentVolumeClaim:
claimName: wp-pv-claim
```
使用curl 命令直接下載配置檔案
1. 下載MySQL部署配置檔案。
```shell
curl -LO https://k8s.io/examples/application/wordpress/mysql-deployment.yaml
```
2. 下載WordPress配置檔案。
```shell
curl -LO https://k8s.io/examples/application/wordpress/wordpress-deployment.yaml
```
3. 將它們新增到`kustomization.yaml`檔案。
```
cat <>./kustomization.yaml
resources:
- mysql-deployment.yaml
- wordpress-deployment.yaml
EOF
```
### 執行並驗證
在`kustomization.yaml`包含用於部署WordPress網站和MySQL資料庫的所有資源。您可以通過以下方式啟動應用
```shell
kubectl apply -k ./
```
現在,您可以驗證所有物件是否存在。
1. 通過執行以下命令來驗證機密是否存在:
```shell
kubectl get secrets
```
響應應如下所示:
```shell
NAME TYPE DATA AGE
mysql-pass-c57bb4t7mf Opaque 1 9s
```
2. 驗證是否已動態配置PersistentVolume。
```shell
kubectl get pvc
```
> **注意:**設定和繫結PV可能要花費幾分鐘。
響應應如下所示:
```shell
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
mysql-pv-claim Bound pvc-8cbd7b2e-4044-11e9-b2bb-42010a800002 20Gi RWO standard 77s
wp-pv-claim Bound pvc-8cd0df54-4044-11e9-b2bb-42010a800002 20Gi RWO standard 77s
```
3. 通過執行以下命令來驗證Pod是否正在執行:
```shell
kubectl get pods
```
> **注意:** Pod的狀態最多可能需要幾分鐘的時間`RUNNING`。
響應應如下所示:
```
NAME READY STATUS RESTARTS AGE
wordpress-mysql-1894417608-x5dzt 1/1 Running 0 40s
```
4. 通過執行以下命令來驗證服務是否正在執行:
```shell
kubectl get services wordpress
```
響應應如下所示:
```
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
wordpress LoadBalancer 10.0.0.89 80:32406/TCP 4m
```
> **注意:** Minikube只能通過公開服務`NodePort`。EXTERNAL-IP始終處於掛起狀態。
>
> 當前我使用的是kind建立叢集,可以直接通過埠轉發方式,進行訪問WordPress頁面
5. 執行以下命令以獲取WordPress服務的IP地址:
```shell
kubectl port-forword --address 0.0.0.0 svc/wordpress 8000:80
```
6. 複製IP地址,然後將頁面載入到瀏覽器中以檢視您的站點。
您應該看到類似於以下螢幕截圖的WordPress設定頁面。
![wordpress初始化](https://raw.githubusercontent.com/kubernetes/examples/master/mysql-wordpress-pd/WordPress.png)
> **警告:**請勿在此頁面上保留WordPress安裝。如果其他使用者找到了它,他們可以在您的例項上建立一個網站並使用它來提供惡意內容。
>
> 通過建立使用者名稱和密碼來安裝WordPress或刪除您的例項。
### 刪除WordPress
1. 執行以下命令以刪除您的金鑰,部署,服務和PersistentVolumeClaims:
```shell
kubectl delete -k .