helm 的安装使用

helm 用途

1. 创建新的chart
2. chart 打包成tgz 格式
3. 上传chart 到 chart 残酷或从仓库中下载chart
4. 在k8s集群中安装或卸载chart
5. 管理用helm安装的 chart的发布周期

重要概念

1. chart 包含了创建k8s的一个应用实例的必要信息
2. config: 包含了应用发布配置信息
3. release: 是一个chart 及其配置的一个运行实例

helm基本使用

仓库

helm 的repo 仓库和 docker registry 比较类似, chart 库可以用来存储和共享打包chart的位置, 我们安装了helm后, 默认的仓库是google一个地址, 可以使用 helm repo list

来查看仓库配置

root@master1 tools]# helm  repo list

添加仓库地址

helm repo add stable https://kubernetes-charts.storage.googleapis.com/
helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo add incubator https://kubernetes-charts-incubator.storage.googleapis.com/

更新

更新

[root@master1 tools]# helm repo update
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "ali-incubator" chart repository
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈Happy Helming!⎈

从chart仓库中 查找 nginx

[root@master1 tools]# helm search repo nginx
NAME CHART VERSION APP VERSION DESCRIPTION

查看chart/mysql 的信息

[root@master1 tools]# helm show chart bitnami/mysql

安装

[root@master1 tools]# helm install nginx bitnami/nginx

查看详细的values值

[root@master1 tools]# helm show  values bitnami/nginx

自定义配置

[root@master1 tools]# cat 1.yaml 
service:
  type: ClusterIP

安装运行测试

helm  install  nginx -f 1.yaml bitnami/nginx --dry-run 

更新升级

[root@master1 tools]# cat 1.yaml 
service:
  type: NodePort

helm upgrade -f 1.yaml nginx  bitnami/nginx

查看历史记录

[root@master1 tools]# helm ls
NAME     NAMESPACE    REVISION    UPDATED                                    STATUS      CHART          APP VERSION
nginx    default      2           2021-06-14 17:43:21.358066771 +0800 CST    deployed    nginx-9.1.0    1.21.0     
[root@master1 tools]# helm history nginx
REVISION    UPDATED                     STATUS        CHART          APP VERSION    DESCRIPTION     
1           Mon Jun 14 17:41:34 2021    superseded    nginx-9.1.0    1.21.0         Install complete
2           Mon Jun 14 17:43:21 2021    deployed      nginx-9.1.0    1.21.0         Upgrade complete

回滚到上一个版本

[root@master1 tools]# helm rollback nginx 1
Rollback was a success! Happy Helming!

[root@master1 tools]# helm history nginx
REVISION    UPDATED                     STATUS        CHART          APP VERSION    DESCRIPTION     
1           Mon Jun 14 17:41:34 2021    superseded    nginx-9.1.0    1.21.0         Install complete
2           Mon Jun 14 17:43:21 2021    deployed      nginx-9.1.0    1.21.0         Upgrade complete

[root@master1 tools]# helm rollback nginx 1
Rollback was a success! Happy Helming!


[root@master1 tools]# helm ls
NAME     NAMESPACE    REVISION    UPDATED                                    STATUS      CHART          APP VERSION
nginx    default      3           2021-06-14 17:47:30.537248127 +0800 CST    deployed    nginx-9.1.0    1.21.0   

  
[root@master1 tools]# helm history nginx
REVISION    UPDATED                     STATUS        CHART          APP VERSION    DESCRIPTION     
1           Mon Jun 14 17:41:34 2021    superseded    nginx-9.1.0    1.21.0         Install complete
2           Mon Jun 14 17:43:21 2021    superseded    nginx-9.1.0    1.21.0         Upgrade complete
3           Mon Jun 14 17:47:30 2021    deployed      nginx-9.1.0    1.21.0         Rollback to 1   

helm 模版之内置函数和values

常见chart包

[root@master1 tools]# helm create helloworld
Creating helloworld
[root@master1 tools]# tree helloworld/
helloworld/
├── charts
├── Chart.yaml
├── templates
│   ├── deployment.yaml
│   ├── _helpers.tpl
│   ├── hpa.yaml
│   ├── ingress.yaml
│   ├── NOTES.txt
│   ├── serviceaccount.yaml
│   ├── service.yaml
│   └── tests
│       └── test-connection.yaml
└── values.yaml

3 directories, 10 files

使用 helm get manifest  name 获取详细信息

[root@master1 tools]# helm get manifest nginx
---
# Source: nginx/templates/server-block-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-server-block
  labels:
    app.kubernetes.io/name: nginx
    helm.sh/chart: nginx-9.1.0
    app.kubernetes.io/instance: nginx
    app.kubernetes.io/managed-by: Helm
data:
  server-blocks-paths.conf: |-
    include  "/opt/bitnami/nginx/conf/server_blocks/ldap/*.conf";
    include  "/opt/bitnami/nginx/conf/server_blocks/common/*.conf";
---
# Source: nginx/templates/svc.yaml
apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app.kubernetes.io/name: nginx
    helm.sh/chart: nginx-9.1.0
    app.kubernetes.io/instance: nginx
    app.kubernetes.io/managed-by: Helm
spec:
  type: LoadBalancer
  externalTrafficPolicy: "Cluster"
  ports:
    - name: http
      port: 80
      targetPort: http
  selector:
    app.kubernetes.io/name: nginx
    app.kubernetes.io/instance: nginx
---
# Source: nginx/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app.kubernetes.io/name: nginx
    helm.sh/chart: nginx-9.1.0
    app.kubernetes.io/instance: nginx
    app.kubernetes.io/managed-by: Helm
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: nginx
      app.kubernetes.io/instance: nginx
  template:
    metadata:
      labels:
        app.kubernetes.io/name: nginx
        helm.sh/chart: nginx-9.1.0
        app.kubernetes.io/instance: nginx
        app.kubernetes.io/managed-by: Helm
    spec:
      
      serviceAccountName: default
      affinity:
        podAffinity:
          
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
            - podAffinityTerm:
                labelSelector:
                  matchLabels:
                    app.kubernetes.io/name: nginx
                    app.kubernetes.io/instance: nginx
                namespaces:
                  - "default"
                topologyKey: kubernetes.io/hostname
              weight: 1
        nodeAffinity:
          
      containers:
        - name: nginx
          image: docker.io/bitnami/nginx:1.21.0-debian-10-r0
          imagePullPolicy: "IfNotPresent"
          env:
            - name: BITNAMI_DEBUG
              value: "false"
          ports:
            - name: http
              containerPort: 8080
          livenessProbe:
            tcpSocket:
              port: http
            periodSeconds: 10
            timeoutSeconds: 5
            successThreshold: 1
            failureThreshold: 6
          readinessProbe:
            tcpSocket:
              port: http
            initialDelaySeconds: 5
            periodSeconds: 5
            timeoutSeconds: 3
            successThreshold: 1
            failureThreshold: 3
          resources:
            limits: {}
            requests: {}
          volumeMounts:
            - name: nginx-server-block-paths
              mountPath: /opt/bitnami/nginx/conf/server_blocks
      volumes:
        - name: nginx-server-block-paths
          configMap:
            name: nginx-server-block
            items:
              - key: server-blocks-paths.conf
                path: server-blocks-paths.conf

内置对象

{{ .Release.Name }} 将 relases的名字插入到模版中,  Release是 helm的内置对象,

Release:  这个对象描述了release本身
1. Release.Name   release 名称
2. Release.Time    release 时间
3. Release.Namespace: release 的namespace
4. Release.Service: release 的服务名称
5. Release.Revision:  release修订版本,从1开始累加
6. Release.isUpgrade: 如果当前操作是升级或者回滚, 则将其设置为true
7. Release.isInstall: 如果当前操作是安装, 则设置为true

vlues: 从values.yaml 文件和用户提供的文件传入模版的值,默认情况下, values是空.

chart: chart.yaml文件的内容, 所有的chart对象都是将从该文件访问,例如
{{ .Chart.Name }} {{ .Chart.Version }}

Files: 这提供了对 chart中所有非特殊文件的访问, 虽然无法使用它来访问模版,但是可以使用它来访问chart中的其他文件

Template: 包含有关正在执行的当前模版信息

helm 模版之管道与控制结构

模版函数

apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Release.Name }}
data:
  nacosserver: "172.16.230.111"
  k8s: {{ quote .Values.k8s.apiserver }}
  python: {{ .Values.python }}

模版函数遵循的语法是: functionName arg1 arg2 , 在上面的模版中, quote.Values.apiserver 调用了 quote函数并将后面的值作为一个参数传递给它. quote 函数是模版中的一个值渲染成字符串

[root@master1 tools]# helm install fengjianconfigmap apiserver --dry-run
NAME: fengjianconfigmap
LAST DEPLOYED: Mon Jun 14 18:53:50 2021
NAMESPACE: default
STATUS: pending-install
REVISION: 1
TEST SUITE: None
HOOKS:
MANIFEST:
---
# Source: apiserver/templates/configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: fengjianconfigmap
data:
  nacosserver: "172.16.230.111"
  k8s: "master1"
  python: list

把k8s指的值变成大写

apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Release.Name }}
data:
  # 如果values.yaml 默认没有定义hello的值,默认是空, 可以使用default 定义一个值
  nacosserver: {{ .Values.hello | default "I don't" | quote }}
  # 转成字符串,再转成大写
  k8s: {{ .Values.k8s.apiserver | quote | upper  }}
  # 转成字符串,并且重复3次
  python: {{ .Values.python | repeat 3 | quote }}