Helm神器,讓管理Kubernetes像yum安裝包一樣簡單

  • 2019 年 10 月 30 日
  • 筆記

一、什麼是Helm

Helm是K8S下的包管理器,相當於apt-get、yum、brew這樣的軟件工具,重點概念

  1. Helm。命令行客戶端工具。主要用於K8S應用程序Chart的創建、打包、發佈及管理倉庫
  2. Tiller。Helm的服務端,用於接收Heml的請求,並根據Chart生成K8S的部署文件(稱為Release),然後提交給K8S創建應用。Tiller還提供了Release的升級、回滾等一系列功能
  3. Chart。Helm的軟件包,採用TAR格式,類似APT的deb或者yum的fpm包,包含了一組定義了K8S資源相關的YAML文件
  4. Repostory。Helm的軟件倉庫,本質上是一個Web服務器,保存了一系列Char軟件包以供用戶下載
  5. Release。使用hel install命令在K8S集群中部署的Chart稱為Release

二、安裝

1.安裝helm客戶端

基本就是brew install之類的,或者使用統一安裝腳本,這裡我用的是brew安裝

brew install kubernetes-helm

2.安裝Tiller

先在每個節點安裝socat軟件,不然會報錯

E0522 22:22:15.492436 24409 portforward.go:331] an error occurred forwarding 38398 -> 44134: error forwarding port 44134 to pod dc6da4ab99ad9c497c0cef1776b9dd18e0a612d507e2746ed63d36ef40f30174, uid : unable to do port forwarding: socat not found.  Error: cannot connect to Tiller

Tiller是以Deployment方式部署到K8S中,只需要使用以下命令安裝

helm init

Helm默認會去storage.googleapis.com拉取鏡像,如果你當前執行的機器不能訪問訪域名的話可以使用以下命令安裝

helm init --client-only --stable-repo-url https://aliacs-app-catalog.oss-cn-hangzhou.aliyuncs.com/charts/  helm repo add incubator https://aliacs-app-catalog.oss-cn-hangzhou.aliyuncs.com/charts-incubator/  helm repo update

3.創建服務端

helm init --service-account tiller --upgrade -i registry.cn-hangzhou.aliyuncs.com/google_containers/tiller:v2.9.1 --stable-repo-url https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts  # 創建TLS認證服務端,參考地址:https://github.com/gjmzj/kubeasz/blob/master/docs/guide/helm.md  helm init --service-account tiller --upgrade -i registry.cn-hangzhou.aliyuncs.com/google_containers/tiller:v2.9.1 --tiller-tls-cert /etc/kubernetes/ssl/tiller001.pem --tiller-tls-key /etc/kubernetes/ssl/tiller001-key.pem --tls-ca-cert /etc/kubernetes/ssl/ca.pem --tiller-namespace kube-system --stable-repo-url https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts

在K8S中安裝Tiller服務,因數官方鏡像無法拉取,可以使用-i指定自己的鏡像,可選鏡像:registry.cn-hangzhou.aliyuncs.com/google_containers/tiller:v2.9.1(阿里雲),該鏡像的版本與helm客戶端的版本相同,使用helm version可查看helm客戶端版本。

4.給Tiller授權

因為Helm的服務端的Tiller是一個部署在kube-system命令空間下的Deployment,它會去連接Kube-Api在K8S里創建和刪除應用
創建 Kubernetes 的服務帳號和綁定角色

kubectl create serviceaccount --namespace kube-system tiller  kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller

5.為 Tiller 設置帳號

# 使用 kubectl patch 更新 API 對象  $ kubectl patch deploy --namespace kube-system tiller-deploy -p '{"spec":{"template":{"spec":{"serviceAccount":"tiller"}}}}'  deployment.extensions "tiller-deploy" patched

查看是否授權成功

kubectl get deploy --namespace kube-system tiller-deploy --output yaml|grep serviceAccount        serviceAccount: tiller        serviceAccountName: tille

6.驗證Tiller是否安裝成功

kubectl -n kube-system get pods|grep tiller  tiller-deploy-6dcc74c957-m7brr 1/1 Running 0 3m39s  ➜ helm-test helm version  Client: &version.Version{SemVer:"v2.15.1", GitCommit:"cf1de4f8ba70eded310918a8af3a96bfe8e7683b", GitTreeState:"clean"}  Server: &version.Version{SemVer:"v2.9.1", GitCommit:"20adb27c7c5868466912eebdf6664e7390ebe710", GitTreeState:"clean"}

卸載Helm服務端Tiller命令

helm reset或  helm reset --force

三、Helm使用

1.更換倉庫

若遇到Unable to get an update from the 「stable」 chart repository (https://kubernetes-charts.storage.googleapis.com) 錯誤,手動更換stable 存儲庫為阿里雲的存儲庫

# 先移除原先的倉庫  helm repo remove stable  # 添加新的倉庫地址  helm repo add stable https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts  # 更新倉庫  helm repo update

2.查看存儲庫中可用的所有Helm chats:

helm search

3.更新charts列表

helm repo update

4.查看已經安裝的chats

helm list

5.關於helm報錯不兼容問題

Helm Error: incompatible versions client[v2.15.0] server[v2.9.1]

解決

brew unlink kubernetes-helm  brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/78d64252f30a12b6f4b3ce29686ab5e262eea812/Formula/kubernetes-helm.rb  brew switch kubernetes-helm 2.9.1

參考鏈接:https://stackoverflow.com/questions/50701224/helm-incompatible-versions-between-client-and-server

四、創建自己的chart

1.建一個cqh的包

➜ helm-test helm create cqh  Creating cqh  ➜ helm-test ls  cqh examples get_helm.sh mongodb tiller.yaml  ➜ helm-test cd cqh  ➜ cqh tree  .  ├── Chart.yaml  ├── charts  ├── templates  │ ├── NOTES.txt  │ ├── _helpers.tpl  │ ├── deployment.yaml  │ ├── ingress.yaml  │ └── service.yaml  └── values.yaml

將values.yaml的鏡像改成nginx:alpine

2.檢查配置和模板是否有效

helm install --dry-run --debug

會輸出包含了模板的變量配置和最終渲染的yaml文件

➜ cqh helm install --dry-run --debug .  [debug] Created tunnel using local port: '62307'    [debug] SERVER: "127.0.0.1:62307"    [debug] Original chart version: ""  [debug] CHART PATH: /Users/chenqionghe/Downloads/helm-test/cqh    NAME: agile-parrot  REVISION: 1  RELEASED: Wed Oct 30 11:09:47 2019  CHART: cqh-0.1.0  USER-SUPPLIED VALUES:  {}    COMPUTED VALUES:  affinity: {}  image:    pullPolicy: IfNotPresent    repository: nginx    tag: alpine  ingress:    annotations: {}    enabled: false    hosts:    - chart-example.local    path: /    tls: []  nodeSelector: {}  replicaCount: 1  resources: {}  service:    port: 80    type: ClusterIP  tolerations: []    HOOKS:  MANIFEST:    ---  # Source: cqh/templates/service.yaml  apiVersion: v1  kind: Service  metadata:    name: agile-parrot-cqh    labels:      app: cqh      chart: cqh-0.1.0      release: agile-parrot      heritage: Tiller  spec:    type: ClusterIP    ports:      - port: 80        targetPort: http        protocol: TCP        name: http    selector:      app: cqh      release: agile-parrot  ---  # Source: cqh/templates/deployment.yaml  apiVersion: apps/v1beta2  kind: Deployment  metadata:    name: agile-parrot-cqh    labels:      app: cqh      chart: cqh-0.1.0      release: agile-parrot      heritage: Tiller  spec:    replicas: 1    selector:      matchLabels:        app: cqh        release: agile-parrot    template:      metadata:        labels:          app: cqh          release: agile-parrot      spec:        containers:          - name: cqh            image: "nginx:alpine"            imagePullPolicy: IfNotPresent            ports:              - name: http                containerPort: 80                protocol: TCP            livenessProbe:              httpGet:                path: /                port: http            readinessProbe:              httpGet:                path: /                port: http            resources:              {}

3.部署到K8S

➜ cqh helm install .  NAME: wintering-jellyfish  LAST DEPLOYED: Wed Oct 30 11:13:30 2019  NAMESPACE: default  STATUS: DEPLOYED    RESOURCES:  ==> v1/Pod(related)  NAME READY STATUS RESTARTS AGE  wintering-jellyfish-cqh-849b9f698c-p6tkz 0/1 ContainerCreating 0 0s    ==> v1/Service  NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE  wintering-jellyfish-cqh ClusterIP 10.43.219.155 <none> 80/TCP 0s    ==> v1beta2/Deployment  NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE  wintering-jellyfish-cqh 1 1 1 0 0s      NOTES:  1. Get the application URL by running these commands:    export POD_NAME=$(kubectl get pods --namespace default -l "app=cqh,release=wintering-jellyfish" -o jsonpath="{.items[0].metadata.name}")    echo "Visit http://127.0.0.1:8080 to use your application"    kubectl port-forward $POD_NAME 8080:80

4.測試訪問

使用安裝後NOTES的提示命令

➜ ~ export POD_NAME=$(kubectl get pods --namespace default -l "app=cqh,release=wintering-jellyfish" -o jsonpath="{.items[0].metadata.name}")    echo "Visit http://127.0.0.1:8080 to use your application"    kubectl port-forward $POD_NAME 8080:80  Visit http://127.0.0.1:8080 to use your application  Forwarding from 127.0.0.1:8080 -> 80  Forwarding from [::1]:8080 -> 80  Handling connection for 8080  Handling connection for 8080  Handling connection for 8080

拉下來就可以使用127.0.0.1:8080訪問這個應用了,safari訪問如下

5.查看部署的release

➜ cqh helm list  NAME REVISION   UPDATED STATUS CHART NAMESPACE  wintering-jellyfish 1 Wed Oct 30 11:13:30 2019  DEPLOYED    cqh-0.1.0   default

6.打包分享

➜ cqh helm package .  Successfully packaged chart and saved it to: /Users/chenqionghe/Downloads/helm-test/cqh/cqh-0.1.0.tgz  ➜ ~ ls ~/.helm/repository/local  cqh-0.1.0.tgz index.yaml

這時候還不能用helm search命令查找到,因為Respository目錄中的Chart包還沒有被Helm管理,可以通過helm repo list看到已經配置的Repository的信息

➜ cqh helm repo list  NAME URL  stable https://kubernetes-charts.storage.googleapis.com  local http://127.0.0.1:8879/charts  incubator   https://aliacs-app-catalog.oss-cn-hangzhou.aliyuncs.com/charts-incubator/

可以在本地啟動一個Repository Server,並將其加入到Helm Repo列表中。
這裡我們就使用 helm serve 命令啟動一個 Repository Server,該 Server 缺省使用 $HOME/.helm/repository/local 目錄作為 Chart 存儲,並在 8879 端口上提供服務。

➜ cqh helm serve  Regenerating index. This may take a moment.  Now serving you on 127.0.0.1:8879

訪問如下

默認情況下該服務只監聽 127.0.0.1,如果你要綁定到其它網絡接口,可使用以下命令:

helm serve --address 192.168.100.211:8879 &

如果想使用指定目錄存儲,可以加上–repo-path

$ helm serve --address 192.168.100.211:8879 --repo-path /data/helm/repository/ --url http://192.168.100.211:8879/charts/

啟動了本地的helm Rpository Server後,就可以將本地Repository加入Helm的Repo列表

➜ ~ helm repo add local http://127.0.0.1:8879  "local" has been added to your repositories  ➜ ~ helm repo list  NAME URL  stable https://kubernetes-charts.storage.googleapis.com  local http://127.0.0.1:8879  incubator   https://aliacs-app-catalog.oss-cn-hangzhou.aliyuncs.com/charts-incubator/

現在可以搜索到了

➜ ~ helm repo update  ➜ ~ helm search cqh  NAME CHART VERSION  APP VERSION DESCRIPTION  local/cqh   0.1.0 1.0 A Helm chart for Kubernetes

7.helm升級和回退一個應用

修改Chart.yaml的0.1.0版本為0.2.0,再使用helm打包發佈到本地人防國

➜ helm-test vim cqh/Chart.yaml  ➜ helm-test helm package cqh  Successfully packaged chart and saved it to: /Users/chenqionghe/Downloads/helm-test/cqh-0.2.0.tgz  ➜ helm-test helm search cqh -l  NAME CHART VERSION  APP VERSION DESCRIPTION  local/cqh   0.2.0 1.0 A Helm chart for Kubernetes  local/cqh   0.1.0 1.0 A Helm chart for Kubernetes

可以看到已經有兩個版本了

升級一個應用使用helm upgrade將已部署的mike-test升級到最新版本,可以使用–version指定版本號

➜ helm-test helm list    NAME REVISION   UPDATED STATUS CHART NAMESPACE  looping-robin   1 Wed Oct 30 13:40:47 2019  DEPLOYED    cqh-0.2.0   default  ➜ helm-test  ➜ helm-test  ➜ helm-test helm upgrade looping-robin local/cqh  Release "looping-robin" has been upgraded. Happy Helming!  LAST DEPLOYED: Wed Oct 30 13:42:08 2019  NAMESPACE: default  STATUS: DEPLOYED    RESOURCES:  ==> v1/Service  NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE  looping-robin-cqh ClusterIP 10.43.204.74 <none> 80/TCP 1m    ==> v1beta2/Deployment  NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE  looping-robin-cqh 1 1 1 1 1m    ==> v1/Pod(related)  NAME READY STATUS RESTARTS AGE  looping-robin-cqh-5bd4c75c64-8qc2k 1/1 Running 0 1m    NOTES:  1. Get the application URL by running these commands:    export POD_NAME=$(kubectl get pods --namespace default -l "app=cqh,release=looping-robin" -o jsonpath="{.items[0].metadata.name}")    echo "Visit http://127.0.0.1:8080 to use your application"    kubectl port-forward $POD_NAME 8080:80

查看歷史升級

➜ helm-test helm history looping-robin  REVISION    UPDATED STATUS CHART DESCRIPTION  1 Wed Oct 30 13:40:47 2019  SUPERSEDED  cqh-0.2.0   Install complete  2 Wed Oct 30 13:42:08 2019  DEPLOYED cqh-0.3.0  Upgrade complete

回退一個應用,根據REVISION的值

helm-test helm rollback looping-robin 1  Rollback was a success! Happy Helming!

8.刪除一個應用

➜ helm-test helm delete looping-robin  release "looping-robin" deleted    ➜ helm-test helm ls -a looping-robin  NAME REVISION   UPDATED STATUS CHART NAMESPACE  looping-robin   3 Wed Oct 30 13:49:37 2019  DELETED cqh-0.2.0   default

如果要移除指定 Release 所有相關 Release 的歷史記錄,可以用如下命令:

➜ helm-test helm delete --purge looping-robin  release "looping-robin" deleted

五、其他

1.自動補全

zsh

$ source <(helm completion zsh)

bash

$ source <(helm completion bash)

2.安裝包如何指定命名空間

helm-test helm install --name=cqh --namespace=web cqh

3.獲取應用的詳細信息

helm get cqh

查看指定版本

helm get  --revision 1  cqh

4.如何解決服務依賴

以下聲明表明 Chart 依賴 Apache 和 MySQL 這兩個第三方 Chart

dependencies:  - name: mariadb  version: 2.1.1  repository: https://kubernetes-charts.storage.googleapis.com/  condition: mariadb.enabled  tags:  - wordpress-database  - name: apache  version: 1.4.0  repository: https://kubernetes-charts.storage.googleapis.com/

5.如何添加第三方庫

helm repo add 存儲庫名 存儲庫URL  helm repo update

參考鏈接:
https://blog.csdn.net/daydayup_668819/article/details/90601967
https://docs.helm.sh/using_helm/#installing-helm
https://mp.weixin.qq.com/s?__biz=MzI3MTI2NzkxMA==&mid=2247486154&idx=1&sn=becd5dd0fadfe0b6072f5dfdc6fdf786&chksm=eac52be3ddb2a2f555b8b1028db97aa3e92d0a4880b56f361e4b11cd252771147c44c08c8913&mpshare=1&scene=24&srcid=0927K11i8Vke44AuSuNdFclU#rd
https://jimmysong.io/kubernetes-handbook/practice/helm.htmlttps://imkira.com/a14.html
https://zhaohuabing.com/2018/04/16/using-helm-to-deploy-to-kubernetes/#undefined
https://help.aliyun.com/document_detail/58587.html?spm=a2c4e.11153940.blogcont159601.20.6703174aRHyZc9