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k8s helm基础

发布时间 2023-09-08 16:59:46作者: 小吉猫

Helm 介绍

Helm是一款将Kubernetes应用打包为“图表”格式，并基于该格式完成应用管理的工具。类似于Linux系统上的yum或apt-get等包管理器，可以帮助用户查找、分享及管理Kubernetes应用程序。

Helm 概念

Chart： 代表着 Helm 包。它包含在 Kubernetes 集群内部运行应用程序，工具或服务所需的所有资源定义。你可以把它看作是 Homebrew formula，Apt dpkg，或 Yum RPM 在Kubernetes 中的等价物。

Repository（仓库）： 是用来存放和共享 charts 的地方。它就像 Perl 的 CPAN 档案库网络 或是 Fedora 的 软件包仓库，只不过它是供 Kubernetes 包所使用的。

Release： 是运行在 Kubernetes 集群中的 chart 的实例。一个 chart 通常可以在同一个集群中安装多次。每一次安装都会创建一个新的 release。以 MySQL chart为例，如果你想在你的集群中运行两个数据库，你可以安装该chart两次。每一个数据库都会拥有它自己的 release 和 release name。

Helm 优势

▪ 管理复杂应用：Chart能够描述哪怕是最复杂的程序结构，提供了可重复使用的应用安装的定义。
▪ 易于升级：使用就地升级和自定义钩子来解决更新的难题。
▪ 简单分享：Chart易于通过公共或私有服务完成版本化、共享及主机构建，且目前有众多成熟的Chart可供使用。
▪ 回滚：使用helm rollback命令轻松实现快速回滚。

Helm 版本支持

Helm 安装

先决条件

1. 使用Helm，需要一个Kubernetes集群。对于Helm的最新版本，我们建议使用Kubernetes的最新稳定版， 在大多数情况下，它是倒数第二个次版本。
2. 部署节点需要有运行 kubectl。

Helm 下载

# wget https://get.helm.sh/helm-v3.12.3-linux-amd64.tar.gz

Helm 解压

# tar xf helm-v3.12.3-linux-amd64.tar.gz
# mv linux-amd64/helm /usr/local/bin/

Helm 验证信息

# helm version
version.BuildInfo{Version:"v3.12.3", GitCommit:"3a31588ad33fe3b89af5a2a54ee1d25bfe6eaa5e", GitTreeState:"clean", GoVersion:"go1.20.7"}

Helm 管理应用示例

helm repo 仓库管理

helm repo 提供了一组命令用于添加、列出和移除仓库。
helm repo add - add a chart repository
helm repo index - generate an index file given a directory containing packaged charts
helm repo list - list chart repositories
helm repo remove - remove one or more chart repositories
helm repo update - update information of available charts locally from chart repositories

示例

# helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
"prometheus-community" has been added to your repositories
# helm repo update
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "prometheus-community" chart repository
Update Complete. ⎈Happy Helming!⎈
# helm repo list
NAME                	URL                                               
prometheus-community	https://prometheus-community.github.io/helm-charts

helm search 查找 Charts

Helm 自带一个强大的搜索命令，可以用来从两种来源中进行搜索：

helm search hub 从 Artifact Hub 中查找并列出 helm charts。 Artifact Hub中存放了大量不同的仓库。
helm search repo 从你添加（使用 helm repo add）到本地 helm 客户端中的仓库中进行查找。该命令基于本地数据进行搜索，无需连接互联网。

示例

# helm search hub prometheus
URL                                               	CHART VERSION 	APP VERSION                                   	DESCRIPTION                                       
https://artifacthub.io/packages/helm/prometheus...	24.3.0        	v2.46.0                                       	Prometheus is a monitoring system and time seri...
https://artifacthub.io/packages/helm/truecharts...	12.1.2        	2.46.0                                        	kube-prometheus-stack collects Kubernetes manif...
...
# helm search repo prometheus
NAME                                              	CHART VERSION	APP VERSION	DESCRIPTION                                       
prometheus-community/kube-prometheus-stack        	50.3.1       	v0.67.1    	kube-prometheus-stack collects Kubernetes manif...
prometheus-community/prometheus                   	24.3.0       	v2.46.0    	Prometheus is a monitoring system and time seri...
prometheus-community/prometheus-adapter           	4.4.1        	v0.11.0    	A Helm chart for k8s prometheus adapter           
prometheus-community/prometheus-blackbox-exporter 	8.3.0        	v0.24.0    	Prometheus Blackbox Exporter                      
prometheus-community/prometheus-cloudwatch-expo...	0.25.1       	0.15.4     	A Helm chart for prometheus cloudwatch-exporter   
prometheus-community/prometheus-conntrack-stats...	0.5.7        	v0.4.15    	A Helm chart for conntrack-stats-exporter         
prometheus-community/prometheus-consul-exporter   	1.0.0        	0.4.0      	A Helm chart for the Prometheus Consul Exporter   
prometheus-community/prometheus-couchdb-exporter  	1.0.0        	1.0        	A Helm chart to export the metrics from couchdb...
prometheus-community/prometheus-druid-exporter    	1.1.0        	v0.11.0    	Druid exporter to monitor druid metrics with Pr...
prometheus-community/prometheus-elasticsearch-e...	5.2.0        	1.5.0      	Elasticsearch stats exporter for Prometheus       
prometheus-community/prometheus-fastly-exporter   	0.1.2        	7.2.4      	A Helm chart for the Prometheus Fastly Exporter   
prometheus-community/prometheus-json-exporter     	0.7.1        	v0.5.0     	Install prometheus-json-exporter                  
prometheus-community/prometheus-kafka-exporter    	2.4.0        	v1.6.0     	A Helm chart to export the metrics from Kafka i...
prometheus-community/prometheus-modbus-exporter   	0.1.0        	0.4.0      	A Helm chart for prometheus-modbus-exporter       
prometheus-community/prometheus-mongodb-exporter  	3.3.0        	0.31.0     	A Prometheus exporter for MongoDB metrics         
prometheus-community/prometheus-mysql-exporter    	2.0.0        	v0.15.0    	A Helm chart for prometheus mysql exporter with...
prometheus-community/prometheus-nats-exporter     	2.13.0       	0.12.0     	A Helm chart for prometheus-nats-exporter         
prometheus-community/prometheus-nginx-exporter    	0.1.1        	0.11.0     	A Helm chart for the Prometheus NGINX Exporter    
prometheus-community/prometheus-node-exporter     	4.23.0       	1.6.1      	A Helm chart for prometheus node-exporter         
prometheus-community/prometheus-operator          	9.3.2        	0.38.1     	DEPRECATED - This chart will be renamed. See ht...
prometheus-community/prometheus-operator-admiss...	0.6.0        	0.67.0     	Prometheus Operator Admission Webhook             
prometheus-community/prometheus-operator-crds     	5.1.0        	0.67.0     	A Helm chart that collects custom resource defi...
prometheus-community/prometheus-pgbouncer-exporter	0.1.1        	1.18.0     	A Helm chart for prometheus pgbouncer-exporter    
prometheus-community/prometheus-pingdom-exporter  	2.5.0        	20190610-1 	A Helm chart for Prometheus Pingdom Exporter      
prometheus-community/prometheus-pingmesh-exporter 	0.3.0        	v1.1.0     	Prometheus Pingmesh Exporter                      
prometheus-community/prometheus-postgres-exporter 	5.0.0        	v0.13.2    	A Helm chart for prometheus postgres-exporter     
prometheus-community/prometheus-pushgateway       	2.4.0        	v1.6.0     	A Helm chart for prometheus pushgateway           
prometheus-community/prometheus-rabbitmq-exporter 	1.8.0        	v0.29.0    	Rabbitmq metrics exporter for prometheus          
prometheus-community/prometheus-redis-exporter    	5.5.0        	v1.44.0    	Prometheus exporter for Redis metrics             
prometheus-community/prometheus-smartctl-exporter 	0.6.0        	v0.11.0    	A Helm chart for Kubernetes                       
prometheus-community/prometheus-snmp-exporter     	1.8.0        	v0.21.0    	Prometheus SNMP Exporter                          
prometheus-community/prometheus-stackdriver-exp...	4.3.0        	0.13.0     	Stackdriver exporter for Prometheus               
prometheus-community/prometheus-statsd-exporter   	0.10.0       	v0.24.0    	A Helm chart for prometheus stats-exporter        
prometheus-community/prometheus-to-sd             	0.4.2        	0.5.2      	Scrape metrics stored in prometheus format and ...
prometheus-community/prometheus-windows-exporter  	0.1.1        	0.22.0     	A Helm chart for prometheus windows-exporter      
prometheus-community/alertmanager                 	1.6.0        	v0.26.0    	The Alertmanager handles alerts sent by client ...
prometheus-community/alertmanager-snmp-notifier   	0.1.2        	v1.4.0     	The SNMP Notifier handles alerts coming from Pr...
prometheus-community/jiralert                     	1.6.0        	v1.3.0     	A Helm chart for Kubernetes to install jiralert   
prometheus-community/kube-state-metrics           	5.13.0       	2.10.0     	Install kube-state-metrics to generate and expo...
prometheus-community/prom-label-proxy             	0.5.0        	v0.6.0     	A proxy that enforces a given label in a given ...

helm show 查看chart信息

helm show all - 显示chart的所有信息
helm show chart - 显示chart定义
helm show crds - 显示chart的CRD
helm show readme - 显示chart的README
helm show values - 显示chart的values

示例

# helm show all prometheus-community/prometheus

helm install 安装一个 helm 包

使用 helm install 命令来安装一个新的 helm 包。最简单的使用方法只需要传入两个参数：你命名的release名字和你想安装的chart的名称。
有六种不同的方式来标识需要安装的chart：

通过chart引用： helm install mymaria example/mariadb
通过chart包： helm install mynginx ./nginx-1.2.3.tgz
通过未打包chart目录的路径： helm install mynginx ./nginx
通过URL绝对路径： helm install mynginx https://example.com/charts/nginx-1.2.3.tgz
通过chart引用和仓库url： helm install --repo https://example.com/charts/ mynginx nginx
通过OCI注册中心： helm install mynginx --version 1.2.3 oci://example.com/charts/nginx
要重写chart中的值，使用'--values'/'-f'参数传递一个文件或者使用'--set'参数在命令行传递配置，强制使用字符串要用'--set-string'。 当值本身对于命令行太长或者是动态生成的时候，可以使用 '--set-file' 设置独立的值。也可以在命令行使用'--set-json'参数设置json值(scalars/objects/arrays)。
helm install [NAME] [CHART] [flags]
为了检测生成的清单，但并不安装到chart，可以将'--debug'和'--dry-run'组合使用。

示例

$ helm install -f myvalues.yaml myredis ./redis

或者

$ helm install --set name=prod myredis ./redis

或者

$ helm install --set-string long_int=1234567890 myredis ./redis

或者

$ helm install --set-file my_script=dothings.sh myredis ./redis

或者

$ helm install --set-json 'master.sidecars=[{"name":"sidecar","image":"myImage","imagePullPolicy":"Always",ports":[{"name":"portname","containerPort":1234}]}]' myredis ./redis

你可以多次指定'--values'/'-f'参数。最右侧指定的文件优先级最高。比如，如果两个文件myvalues.yaml和override.yaml 都包含名为'Test'的可以，override.yaml中的值优先：

$ helm install -f myvalues.yaml -f override.yaml  myredis ./redis

可以指定'--set'参数多次，最右边的参数优先级最高，比如，'bar'和'newbar'都设置了一个名为'foo'的可以，'newbar'的值优先：

    $ helm install --set foo=bar --set foo=newbar  myredis ./redis

类似地,下面的示例中'foo'被设置成了'["four"]':

    $ helm install --set-json='foo=["one", "two", "three"]' --set-json='foo=["four"]' myredis ./redis

下面的示例中，'foo'被设置成了'{"key1":"value1","key2":"bar"}'：

    $ helm install --set-json='foo={"key1":"value1","key2":"value2"}' --set-json='foo.key2="bar"' myredis ./redis

helm list

列出的已经安装生成的Release.
如果未找到结果，'helm list'会退出，但是没有输出(或者使用'-q'，只返回头部）。

默认情况下，最多返回256项，使用'--max'限制数量，'--max'设置为0不会返回所有结果，而是返回服务器默认值，可能要比256更多。 同时使用'--max'和'--offset'参数可以翻页显示。

示例

$ helm list --filter 'ara[a-z]+'

helm upgrade

当你想升级到 chart 的新版本，或是修改 release 的配置，你可以使用 helm upgrade 命令。

示例

$ helm upgrade -f panda.yaml happy-panda bitnami/wordpress

在上面的例子中，happy-panda 这个 release 使用相同的 chart 进行升级，但是使用了一个新的 YAML 文件：

mariadb.auth.username: user1

helm get

对于运行中的Release，我们可以使用helm get命令获取相关的钩子、最终资源配置清单、注意事项和用户自定义的模板参数值信息，相关信息的获取各自依赖于相关的子命令，或者直接使用子命令all一次性地列出所有这些信息。
helm get all - download all information for a named release
helm get hooks - download all hooks for a named release
helm get manifest - download the manifest for a named release
helm get notes - download the notes for a named release
helm get values - download the values file for a named release

示例

$ helm get values happy-panda
mariadb:
  auth:
    username: user1

helm rollback

假如在一次发布过程中，发生了不符合预期的事情，也很容易通过 helm rollback [RELEASE] [REVISION] 命令回滚到之前的发布版本。
$ helm rollback happy-panda 1

helm uninstall

使用 helm uninstall 命令从集群中卸载一个 release。
在 Helm 3 中，删除也会移除 release 的记录。 如果你想保留删除记录，使用 helm uninstall --keep-history。使用 helm list --uninstalled 只会展示使用了 --keep-history 删除的 release。

示例

$ helm uninstall happy-panda

Helm 帮助信息

The Kubernetes package manager

Common actions for Helm:

- helm search:    search for charts
- helm pull:      download a chart to your local directory to view
- helm install:   upload the chart to Kubernetes
- helm list:      list releases of charts

Environment variables:

| Name                               | Description                                                                                       |
|------------------------------------|---------------------------------------------------------------------------------------------------|
| $HELM_CACHE_HOME                   | set an alternative location for storing cached files.                                             |
| $HELM_CONFIG_HOME                  | set an alternative location for storing Helm configuration.                                       |
| $HELM_DATA_HOME                    | set an alternative location for storing Helm data.                                                |
| $HELM_DEBUG                        | indicate whether or not Helm is running in Debug mode                                             |
| $HELM_DRIVER                       | set the backend storage driver. Values are: configmap, secret, memory, sql.                       |
| $HELM_DRIVER_SQL_CONNECTION_STRING | set the connection string the SQL storage driver should use.                                      |
| $HELM_MAX_HISTORY                  | set the maximum number of helm release history.                                                   |
| $HELM_NAMESPACE                    | set the namespace used for the helm operations.                                                   |
| $HELM_NO_PLUGINS                   | disable plugins. Set HELM_NO_PLUGINS=1 to disable plugins.                                        |
| $HELM_PLUGINS                      | set the path to the plugins directory                                                             |
| $HELM_REGISTRY_CONFIG              | set the path to the registry config file.                                                         |
| $HELM_REPOSITORY_CACHE             | set the path to the repository cache directory                                                    |
| $HELM_REPOSITORY_CONFIG            | set the path to the repositories file.                                                            |
| $KUBECONFIG                        | set an alternative Kubernetes configuration file (default "~/.kube/config")                       |
| $HELM_KUBEAPISERVER                | set the Kubernetes API Server Endpoint for authentication                                         |
| $HELM_KUBECAFILE                   | set the Kubernetes certificate authority file.                                                    |
| $HELM_KUBEASGROUPS                 | set the Groups to use for impersonation using a comma-separated list.                             |
| $HELM_KUBEASUSER                   | set the Username to impersonate for the operation.                                                |
| $HELM_KUBECONTEXT                  | set the name of the kubeconfig context.                                                           |
| $HELM_KUBETOKEN                    | set the Bearer KubeToken used for authentication.                                                 |
| $HELM_KUBEINSECURE_SKIP_TLS_VERIFY | indicate if the Kubernetes API server's certificate validation should be skipped (insecure)       |
| $HELM_KUBETLS_SERVER_NAME          | set the server name used to validate the Kubernetes API server certificate                        |
| $HELM_BURST_LIMIT                  | set the default burst limit in the case the server contains many CRDs (default 100, -1 to disable)|

Helm stores cache, configuration, and data based on the following configuration order:

- If a HELM_*_HOME environment variable is set, it will be used
- Otherwise, on systems supporting the XDG base directory specification, the XDG variables will be used
- When no other location is set a default location will be used based on the operating system

By default, the default directories depend on the Operating System. The defaults are listed below:

| Operating System | Cache Path                | Configuration Path             | Data Path               |
|------------------|---------------------------|--------------------------------|-------------------------|
| Linux            | $HOME/.cache/helm         | $HOME/.config/helm             | $HOME/.local/share/helm |
| macOS            | $HOME/Library/Caches/helm | $HOME/Library/Preferences/helm | $HOME/Library/helm      |
| Windows          | %TEMP%\helm               | %APPDATA%\helm                 | %APPDATA%\helm          |

Usage:
  helm [command]

Available Commands:
  completion  generate autocompletion scripts for the specified shell
  create      create a new chart with the given name
  dependency  manage a chart's dependencies
  env         helm client environment information
  get         download extended information of a named release
  help        Help about any command
  history     fetch release history
  install     install a chart
  lint        examine a chart for possible issues
  list        list releases
  package     package a chart directory into a chart archive
  plugin      install, list, or uninstall Helm plugins
  pull        download a chart from a repository and (optionally) unpack it in local directory
  push        push a chart to remote
  registry    login to or logout from a registry
  repo        add, list, remove, update, and index chart repositories
  rollback    roll back a release to a previous revision
  search      search for a keyword in charts
  show        show information of a chart
  status      display the status of the named release
  template    locally render templates
  test        run tests for a release
  uninstall   uninstall a release
  upgrade     upgrade a release
  verify      verify that a chart at the given path has been signed and is valid
  version     print the client version information

Flags:
      --burst-limit int                 client-side default throttling limit (default 100)
      --debug                           enable verbose output
  -h, --help                            help for helm
      --kube-apiserver string           the address and the port for the Kubernetes API server
      --kube-as-group stringArray       group to impersonate for the operation, this flag can be repeated to specify multiple groups.
      --kube-as-user string             username to impersonate for the operation
      --kube-ca-file string             the certificate authority file for the Kubernetes API server connection
      --kube-context string             name of the kubeconfig context to use
      --kube-insecure-skip-tls-verify   if true, the Kubernetes API server's certificate will not be checked for validity. This will make your HTTPS connections insecure
      --kube-tls-server-name string     server name to use for Kubernetes API server certificate validation. If it is not provided, the hostname used to contact the server is used
      --kube-token string               bearer token used for authentication
      --kubeconfig string               path to the kubeconfig file
  -n, --namespace string                namespace scope for this request
      --registry-config string          path to the registry config file (default "/root/.config/helm/registry/config.json")
      --repository-cache string         path to the file containing cached repository indexes (default "/root/.cache/helm/repository")
      --repository-config string        path to the file containing repository names and URLs (default "/root/.config/helm/repositories.yaml")

Use "helm [command] --help" for more information about a command.

参考文档

https://github.com/helm/helm

helm hub： https://artifacthub.io/