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本篇内容主要讲解“helm的部署和简单使用”,感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷,实用性强。下面就让小编来带大家学习“helm的部署和简单使用”吧!
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Helm通过软件打包的形式,支持发布的版本管理和控制,很大程度上简化了Kubernetes应用部署和管理的复杂性。
随着业务容器化与向微服务架构转变,通过分解巨大的单体应用为多个服务的方式,分解了单体应用的复杂性,使每个微服务都可以独立部署和扩展,实现了敏捷开发和快速迭代和部署。但任何事情都有两面性,虽然微服务给我们带来了很多便利,但由于应用被拆分成多个组件,导致服务数量大幅增加,对于Kubernetest编排来说,每个组件有自己的资源文件,并且可以独立的部署与伸缩,这给采用Kubernetes做应用编排带来了诸多挑战:
管理、编辑与更新大量的K8s配置文件
部署一个含有大量配置文件的复杂K8s应用
分享和复用K8s配置和应用
参数化配置模板支持多个环境
管理应用的发布:回滚、diff和查看发布历史
控制一个部署周期中的某一些环节
发布后的验证
而Helm恰好可以帮助我们解决上面问题。
Helm把Kubernetes资源(比如deployments、services或 ingress等) 打包到一个chart中,而chart被保存到chart仓库。通过chart仓库来存储和分享chart。Helm使发布可配置,支持发布应用配置的版本管理,简化了Kubernetes部署应用的版本控制、打包、发布、删除、更新等操作。
本文简单介绍了Helm的用途、架构、安装和使用。
做为Kubernetes的一个包管理工具,Helm具有如下功能:
创建新的chart
chart打包成tgz格式
上传chart到chart仓库或从仓库中下载chart
在Kubernetes集群中安装或卸载chart
管理用Helm安装的chart的发布周期
Helm有三个重要概念:
chart:包含了创建Kubernetes的一个应用实例的必要信息
config:包含了应用发布配置信息
release:是一个chart及其配置的一个运行实例
Helm有以下两个组成部分:
Helm Client是用户命令行工具,其主要负责如下:
本地chart开发
仓库管理
与Tiller sever交互
发送预安装的chart
查询release信息
要求升级或卸载已存在的release
Tiller server是一个部署在Kubernetes集群内部的server,其与Helm client、Kubernetes API server进行交互,主要负责如下:
监听来自Helm client的请求
通过chart及其配置构建一次发布
安装chart到Kubernetes集群,并跟踪随后的发布
通过与Kubernetes交互升级或卸载chart
简单的说,client管理charts,而server管理发布release。
Helm client
Helm client采用go语言编写,采用gRPC
协议与Tiller server交互。
Helm server
Tiller server也同样采用go语言编写,提供了gRPC server与helm client进行交互,利用Kubernetes client 库与Kubernetes进行通信,当前库使用了REST+JSON
格式。
Tiller server 没有自己的数据库,目前使用Kubernetes的ConfigMaps
存储相关信息
说明:配置文件尽可能使用YAM格式
如果与我的情况不同,请阅读官方的quick guide,了安装的核心流程和多种情况。
Helm Release地址
kubernetes集群
了解kubernetes的Context安全机制
下载helm的安装包wget https://storage.googleapis.com/kubernetes-helm/helm-v2.11.0-linux-amd64.tar.gz
我的环境使用了RBAC(Role-Based Access Control )
的授权方式,需要先配置ServiceAccount和规则,然后再安装helm。官方配置参考Role-based Access Control文档。
权限管理yml:
apiVersion: v1 kind: ServiceAccount metadata: name: tiller namespace: kube-system --- apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: name: tiller roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: cluster-admin subjects: - kind: ServiceAccount name: tiller namespace: kube-system
cluster-admin
是kubernetes默认创建的角色。不需要重新定义。
安装helm:
$ kubectl create -f rbac-config.yaml serviceaccount "tiller" created clusterrolebinding "tiller" created $ helm init --service-account tiller
运行结果:
$HELM_HOME has been configured at /root/.helm. Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster. Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy. To prevent this, run `helm init` with the --tiller-tls-verify flag. For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation Happy Helming!
实验环境建议使用本方式安装,然后安装ingress-nginx等系统组件。
配置helm 安装在helm-system
namespace,允许Tiller发布应用到kube-public
namespace。
创建helm-system
namespace,使用命令kubectl create namespace helm-system
定义ServiceAccount
--- kind: ServiceAccount apiVersion: v1 metadata: name: tiller namespace: helm-system
创建一个Role,拥有namespace kube-public
的所有权限。将Tiller的ServiceAccount绑定到这个角色上,允许Tiller 管理kube-public
namespace 所有的资源。
--- kind: Role apiVersion: rbac.authorization.k8s.io/v1 metadata: name: tiller-manager namespace: kube-public rules: - apiGroups: ["", "extensions", "apps"] resources: ["*"] verbs: ["*"] --- kind: RoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: tiller-binding namespace: kube-public subjects: - kind: ServiceAccount name: tiller namespace: helm-system roleRef: kind: Role name: tiller-manager apiGroup: rbac.authorization.k8s.io
Helm中的Release信息存储在Tiller安装的namespace中的ConfigMap
,即helm-system
,需要允许Tiller操作helm-system
的ConfigMap
。所以创建Role helm-system.tiller-manager
,并绑定到ServiceAccounthelm-system.tiller
--- kind: Role apiVersion: rbac.authorization.k8s.io/v1 metadata: namespace: helm-system name: tiller-manager rules: - apiGroups: ["", "extensions", "apps"] resources: ["configmaps"] verbs: ["*"] --- kind: RoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: tiller-binding namespace: helm-system subjects: - kind: ServiceAccount name: tiller namespace: helm-system roleRef: kind: Role name: tiller-manager apiGroup: rbac.authorization.k8s.io
使用命令`helm init --service-account tiller --tiller-namespace helm-system`安装helm。
helm init
参数说明:
--service-account
:指定helm Tiller的ServiceAccount,对于启用了kubernetesRBAC的集群适用。
--tiller-namespace
:将helm 安装到指定的namespace中;
--tiller-image
:指定helm镜像
--kube-context
:将helm Tiller安装到特定的kubernetes集群中;
第一次运行出现问题:
[root@kuber24 helm]# helm init --service-account tiller --tiller-namespace helm-system Creating /root/.helm Creating /root/.helm/repository Creating /root/.helm/repository/cache Creating /root/.helm/repository/local Creating /root/.helm/plugins Creating /root/.helm/starters Creating /root/.helm/cache/archive Creating /root/.helm/repository/repositories.yaml Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com Error: Looks like "https://kubernetes-charts.storage.googleapis.com" is not a valid chart repository or cannot be reached: Get https://kubernetes-charts.storage.googleapis.com/index.yaml: EOF
这个是由于google的都被墙了,修改Hosts,指定storage.googleapis.com
对应的课访问的IP即可。最新的国内可访问google的Hosts配置见github项目googlehosts/hosts的hosts/hosts-files/hosts文件。
再次运行init helm命令,成功安装。
[root@kuber24 helm]# helm init --service-account tiller --tiller-namespace helm-system Creating /root/.helm/repository/repositories.yaml Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com Adding local repo with URL: http://127.0.0.1:8879/charts $HELM_HOME has been configured at /root/.helm. Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster. Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy. To prevent this, run `helm init` with the --tiller-tls-verify flag. For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation Happy Helming!
查看Tiller的Pod状态时,发现Pod出现错误ImagePullBackOff
,如下:
[root@kuber24 resources]# kubectl get pods --all-namespaces|grep tiller helm-system tiller-deploy-cdcd5dcb5-fqm57 0/1 ImagePullBackOff 0 13m
查看pod的详细信息kubectl describe pod tiller-deploy-cdcd5dcb5-fqm57 -n helm-system
,发现Pod依赖镜像gcr.io/kubernetes-helm/tiller:v2.11.0
。
查询docker hub上是否有人复制过改镜像,如图:
[root@kuber24 ~]# docker search tiller:v2.11.0 INDEX NAME DESCRIPTION STARS OFFICIAL AUTOMATED docker.io docker.io/jay1991115/tiller gcr.io/kubernetes-helm/tiller:v2.11.0 1 [OK] docker.io docker.io/luyx30/tiller tiller:v2.11.0 1 [OK] docker.io docker.io/1017746640/tiller FROM gcr.io/kubernetes-helm/tiller:v2.11.0 0 [OK] docker.io docker.io/724399396/tiller gcr.io/kubernetes-helm/tiller:v2.11.0-rc.2... 0 [OK] docker.io docker.io/fengzos/tiller gcr.io/kubernetes-helm/tiller:v2.11.0 0 [OK] docker.io docker.io/imwower/tiller tiller from gcr.io/kubernetes-helm/tiller:... 0 [OK] docker.io docker.io/xiaotech/tiller FROM gcr.io/kubernetes-helm/tiller:v2.11.0 0 [OK] docker.io docker.io/yumingc/tiller tiller:v2.11.0 0 [OK] docker.io docker.io/zhangc476/tiller gcr.io/kubernetes-helm/tiller/kubernetes-h... 0 [OK]
同样使用hub.docker.com
上mirrorgooglecontainers
加速的google镜像,然后改镜像的名字。每个Node节点都需要安装。
镜像下载不下来:使用他人同步到docker hub上面的镜像;使用docker search $NAME:$VERSION
使用Hosts翻墙实现。
问题提示:
[root@kuber24 ~]# helm install nginx --tiller-namespace helm-system --namespace kube-public Error: failed to download "nginx" (hint: running `helm repo update` may help)
使用helm repo update
后,并没有解决问题。
如下:
[root@kuber24 ~]# helm install nginx --tiller-namespace helm-system --namespace kube-public Error: failed to download "nginx" (hint: running `helm repo update` may help) [root@kuber24 ~]# helm repo update Hang tight while we grab the latest from your chart repositories... ...Skip local chart repository ...Successfully got an update from the "stable" chart repository Update Complete. ⎈ Happy Helming!⎈ [root@kuber24 ~]# helm install nginx --tiller-namespace helm-system --namespace kube-public Error: failed to download "nginx" (hint: running `helm repo update` may help)
可能的原因:
没有nginx这个chart:使用helm search nginx
查询nginx chart信息。
网络连接问题,下载不了。这种情况下,等待一定超时后,helm会提示。
添加aliyun, github 和官方incubator charts repository。
helm add repo gitlab https://charts.gitlab.io/ helm repo add aliyun https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts helm repo add incubator https://kubernetes-charts-incubator.storage.googleapis.com/
本小结的$NAME
表示helm的repo/chart_name。
查询charts: helm search $NAME
查看release的列表:helm ls [--tiller-namespace $TILLER_NAMESPACE]
查询package 信息: helm inspect $NAME
查询package支持的选项:helm inspect values $NAME
部署chart:helm install $NAME [--tiller-namespace $TILLER_NAMESPACE] [--namespace $CHART_DEKPLOY_NAMESPACE]
删除release:helm delete $RELEASE_NAME [--purge] [--tiller-namespace $TILLER_NAMESPACE]
更新:helm upgrade --set $PARAM_NAME=$PARAM_VALUE $RELEASE_NAME $NAME [--tiller-namespace $TILLER_NAMESPACE]
回滚:helm rollback $RELEASE_NAME $REVERSION [--tiller-namespace $TILLER_NAMESPACE]
删除release时,不使用
--purge
参数,会仅撤销pod部署,不会删除release的基本信息,不能release同名的chart。
部署MySQL时,查询参数并配置相应的参数。
查询可配置的参数:
[root@kuber24 charts]# helm inspect values aliyun/mysql ## mysql image version ## ref: https://hub.docker.com/r/library/mysql/tags/ ## image: "mysql" imageTag: "5.7.14" ## Specify password for root user ## ## Default: random 10 character string # mysqlRootPassword: testing ## Create a database user ## # mysqlUser: # mysqlPassword: ## Allow unauthenticated access, uncomment to enable ## # mysqlAllowEmptyPassword: true ## Create a database ## # mysqlDatabase: ## Specify an imagePullPolicy (Required) ## It's recommended to change this to 'Always' if the image tag is 'latest' ## ref: http://kubernetes.io/docs/user-guide/images/#updating-images ## imagePullPolicy: IfNotPresent livenessProbe: initialDelaySeconds: 30 periodSeconds: 10 timeoutSeconds: 5 successThreshold: 1 failureThreshold: 3 readinessProbe: initialDelaySeconds: 5 periodSeconds: 10 timeoutSeconds: 1 successThreshold: 1 failureThreshold: 3 ## Persist data to a persistent volume persistence: enabled: true ## database data Persistent Volume Storage Class ## If defined, storageClassName:## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName spec is ## set, choosing the default provisioner. (gp2 on AWS, standard on ## GKE, AWS & OpenStack) ## # storageClass: "-" accessMode: ReadWriteOnce size: 8Gi ## Configure resource requests and limits ## ref: http://kubernetes.io/docs/user-guide/compute-resources/ ## resources: requests: memory: 256Mi cpu: 100m # Custom mysql configuration files used to override default mysql settings configurationFiles: # mysql.cnf: |- # [mysqld] # skip-name-resolve ## Configure the service ## ref: http://kubernetes.io/docs/user-guide/services/ service: ## Specify a service type ## ref: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services---service-types type: ClusterIP port: 3306 # nodePort: 32000
例如我们需要配置mysql的root密码,那么可以直接使用--set
参数设置选项,例如roo密码设置:--set mysqlRootPassword=hgfgood
。
通过mysql选项的说明中persistence
参数,可以看出mysql 需要持久化存储,所以需要给kubernetes配置持久化存储卷PV。
创建PV:
[root@kuber24 resources]# cat local-pv.yml apiVersion: v1 kind: PersistentVolume metadata: name: local-pv namespace: kube-public spec: capacity: storage: 30Gi accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Recycle hostPath: path: /home/k8s
完整的release chart命令如下:helm install --name mysql-dev --set mysqlRootPassword=hgfgood aliyun/mysql --tiller-namespace helm-system --namespace kube-public
。
查看已经release的chart列表:
[root@kuber24 charts]# helm ls --tiller-namespace=helm-system NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE mysql-dev 1 Fri Oct 26 10:35:55 2018 DEPLOYED mysql-0.3.5 kube-public
正常情况下,dashboard监控的情况如下图:
运行此mysql chart 需要busybox镜像,偶尔会出现下图所示的问题,这是docker默认访问国外的docker hub导致的。需要先下载busybox镜像。
上例中,安装完mysql,使用的root密码为hgfgood
。本例中将其更新为hgf
然后回滚到原始的密码hgfgood
。
查询mysql安装后的密码:
[root@kuber24 charts]# kubectl get secret --namespace kube-public mysql-dev-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo hgfgood
更新mysql的root密码,helm upgrade --set mysqlRootPassword=hgf mysql-dev mysql --tiller-namespace helm-system
更新完成后再次查询mysql的root用户密码
[root@kuber24 charts]# kubectl get secret --namespace kube-public mysql-dev-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo hgf
查看RELEASE的信息:
[root@kuber24 charts]# helm ls --tiller-namespace helm-system NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE mysql-dev 2 Fri Oct 26 11:26:48 2018 DEPLOYED mysql-0.3.5 kube-public
查看REVISION
,可以目前mysql-dev
有两个版本。
回滚到版本1
:
[root@kuber24 charts]# helm rollback mysql-dev 1 --tiller-namespace helm-system Rollback was a success! Happy Helming! [root@kuber24 charts]# kubectl get secret --namespace kube-public mysql-dev-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo hgfgood
通过上述输出可以发现RELEASE已经回滚。
Error: could not find tiller
,使用helm client,需要与tiller 交互时,需要制定tiller的namespace,使用参数--tiller-namespace helm-system
,此参数默认时kube-system
。
由于网络问题下载会失败的问题,例如:
[root@kuber24 ~]# helm install stable/mysql --tiller-namespace helm-system --namespace kube-public --debug [debug] Created tunnel using local port: '32774' [debug] SERVER: "127.0.0.1:32774" [debug] Original chart version: "" Error: Get https://kubernetes-charts.storage.googleapis.com/mysql-0.10.2.tgz: read tcp 10.20.13.24:56594->216.58.221.240:443: read: connection reset by peer
进入本地charts保存的目录
使用阿里云fetch对应的chart
例如 安装mysql。
helm fetch aliyun/mysql --untar [root@kuber24 charts]# ls mysql [root@kuber24 charts]# ls mysql/ Chart.yaml README.md templates values.yaml
然后再次运行helm install
安装mysql chart。
helm install mysql --tiller-namespace helm-system --namespace kube-public
可以使用--debug
参数,打开debug信息。
[root@kuber24 charts]# helm install mysql --tiller-namespace helm-system --namespace kube-public --debug [debug] Created tunnel using local port: '41905' [debug] SERVER: "127.0.0.1:41905" [debug] Original chart version: "" [debug] CHART PATH: /root/Downloads/charts/mysql NAME: kissable-bunny REVISION: 1 RELEASED: Thu Oct 25 20:20:23 2018 CHART: mysql-0.3.5 USER-SUPPLIED VALUES: {} COMPUTED VALUES: configurationFiles: null image: mysql imagePullPolicy: IfNotPresent imageTag: 5.7.14 livenessProbe: failureThreshold: 3 initialDelaySeconds: 30 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 5 persistence: accessMode: ReadWriteOnce enabled: true size: 8Gi readinessProbe: failureThreshold: 3 initialDelaySeconds: 5 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1 resources: requests: cpu: 100m memory: 256Mi service: port: 3306 type: ClusterIP HOOKS: MANIFEST: --- # Source: mysql/templates/secrets.yaml apiVersion: v1 kind: Secret metadata: name: kissable-bunny-mysql labels: app: kissable-bunny-mysql chart: "mysql-0.3.5" release: "kissable-bunny" heritage: "Tiller" type: Opaque data: mysql-root-password: "TzU5U2tScHR0Sg==" mysql-password: "RGRXU3Ztb3hQNw==" --- # Source: mysql/templates/pvc.yaml kind: PersistentVolumeClaim apiVersion: v1 metadata: name: kissable-bunny-mysql labels: app: kissable-bunny-mysql chart: "mysql-0.3.5" release: "kissable-bunny" heritage: "Tiller" spec: accessModes: - "ReadWriteOnce" resources: requests: storage: "8Gi" --- # Source: mysql/templates/svc.yaml apiVersion: v1 kind: Service metadata: name: kissable-bunny-mysql labels: app: kissable-bunny-mysql chart: "mysql-0.3.5" release: "kissable-bunny" heritage: "Tiller" spec: type: ClusterIP ports: - name: mysql port: 3306 targetPort: mysql selector: app: kissable-bunny-mysql --- # Source: mysql/templates/deployment.yaml apiVersion: extensions/v1beta1 kind: Deployment metadata: name: kissable-bunny-mysql labels: app: kissable-bunny-mysql chart: "mysql-0.3.5" release: "kissable-bunny" heritage: "Tiller" spec: template: metadata: labels: app: kissable-bunny-mysql spec: initContainers: - name: "remove-lost-found" image: "busybox:1.25.0" imagePullPolicy: "IfNotPresent" command: ["rm", "-fr", "/var/lib/mysql/lost+found"] volumeMounts: - name: data mountPath: /var/lib/mysql containers: - name: kissable-bunny-mysql image: "mysql:5.7.14" imagePullPolicy: "IfNotPresent" resources: requests: cpu: 100m memory: 256Mi env: - name: MYSQL_ROOT_PASSWORD valueFrom: secretKeyRef: name: kissable-bunny-mysql key: mysql-root-password - name: MYSQL_PASSWORD valueFrom: secretKeyRef: name: kissable-bunny-mysql key: mysql-password - name: MYSQL_USER value: "" - name: MYSQL_DATABASE value: "" ports: - name: mysql containerPort: 3306 livenessProbe: exec: command: - sh - -c - "mysqladmin ping -u root -p${MYSQL_ROOT_PASSWORD}" initialDelaySeconds: 30 periodSeconds: 10 timeoutSeconds: 5 successThreshold: 1 failureThreshold: 3 readinessProbe: exec: command: - sh - -c - "mysqladmin ping -u root -p${MYSQL_ROOT_PASSWORD}" initialDelaySeconds: 5 periodSeconds: 10 timeoutSeconds: 1 successThreshold: 1 failureThreshold: 3 volumeMounts: - name: data mountPath: /var/lib/mysql volumes: - name: data persistentVolumeClaim: claimName: kissable-bunny-mysql LAST DEPLOYED: Thu Oct 25 20:20:23 2018 NAMESPACE: kube-public STATUS: DEPLOYED RESOURCES: ==> v1/Pod(related) NAME READY STATUS RESTARTS AGE kissable-bunny-mysql-c7df69d65-lmjzn 0/1 Pending 0 0s ==> v1/Secret NAME AGE kissable-bunny-mysql 1s ==> v1/PersistentVolumeClaim kissable-bunny-mysql 1s ==> v1/Service kissable-bunny-mysql 1s ==> v1beta1/Deployment kissable-bunny-mysql 1s NOTES: MySQL can be accessed via port 3306 on the following DNS name from within your cluster: kissable-bunny-mysql.kube-public.svc.cluster.local To get your root password run: MYSQL_ROOT_PASSWORD=$(kubectl get secret --namespace kube-public kissable-bunny-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo) To connect to your database: 1. Run an Ubuntu pod that you can use as a client: kubectl run -i --tty ubuntu --image=ubuntu:16.04 --restart=Never -- bash -il 2. Install the mysql client: $ apt-get update && apt-get install mysql-client -y 3. Connect using the mysql cli, then provide your password: $ mysql -h kissable-bunny-mysql -p To connect to your database directly from outside the K8s cluster: MYSQL_HOST=127.0.0.1 MYSQL_PORT=3306 # Execute the following commands to route the connection: export POD_NAME=$(kubectl get pods --namespace kube-public -l "app=kissable-bunny-mysql" -o jsonpath="{.items[0].metadata.name}") kubectl port-forward $POD_NAME 3306:3306 mysql -h ${MYSQL_HOST} -P${MYSQL_PORT} -u root -p${MYSQL_ROOT_PASSWORD}
[ ] 详细的打包实验。
# 创建一个新的 chart helm create hello-chart # validate chart helm lint # 打包 chart 到 tgz helm package hello-chart
到此,相信大家对“helm的部署和简单使用”有了更深的了解,不妨来实际操作一番吧!这里是创新互联网站,更多相关内容可以进入相关频道进行查询,关注我们,继续学习!