Helmのサブコマンドを全部使ってみた

2021.01.28

Helmの勉強のために、各サブコマンドで何ができるか調べました。

環境情報

EKS Workshopで使う、Cloud 9インスタンス上で検証しています。Linuxです。

Helmのバージョンは以下です。

$ helm version 
version.BuildInfo{Version:"v3.5.0", GitCommit:"32c22239423b3b4ba6706d450bd044baffdcf9e6", GitTreeState:"clean", GoVersion:"go1.15.6"}

completion

generate autocompletions script for the specified shell

シェル自動補完のためのスクリプトを吐いてくれます。

各シェル用のサブコマンドがあります。

Available Commands:
  bash        generate autocompletion script for bash
  fish        generate autocompletion script for fish
  zsh         generate autocompletion script for zsh

例えばbashの場合、現在のシェルセッションで自動補完を有効化するには、以下のコマンドを実行します。

$ source <(helm completion bash)

今後のセッションで自動補完を有効化するには、以下のコマンドを実行します。

$ helm completion bash >> ~/.bash_completion

そうすると、helm以降のサブコマンドの自動補完が効くようになります。

$ helm (ここでTabを押す)
completion  dependency  get         install     list        plugin      repo        search      status      test        upgrade     version     
create      env         history     lint        package     pull        rollback    show        template    uninstall   verify

create

create a new chart with the given name

独自のチャートを作成します。EKS Workshopでも登場します。

$ helm create eksdemo
Creating eksdemo
$ tree eksdemo/
eksdemo/
├── 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

こんな感じで、チャートの雛形を作ってくれます。

--starter もしくは -pオプションがあります。これは他のチャートを雛形として新しいチャートを作るオプションです。

雛形となるチャートは$XDG_DATA_HOME/helm/startersに存在している必要があります。

$ mkdir -p /home/ec2-user/.local/share/helm/starters/
$ cp -r eksdemo /home/ec2-user/.local/share/helm/starters/
$ helm create eksdemo2 --starter eksdemo 
Creating eksdemo2

dependency

manage a chart's dependencies

チャートは別のチャートに依存している場合があります。そのような依存関係を管理するコマンドです。

以下のサブコマンドがあります。

Available Commands:
  build       rebuild the charts/ directory based on the Chart.lock file
  list        list the dependencies for the given chart
  update      update charts/ based on the contents of Chart.yaml

先程作ったチャートeksdemoは現在中身空っぽなので何の依存関係もありません。

$ helm dependency list eksdemo
WARNING: no dependencies at eksdemo/charts

依存関係があるチャートをダウンロードしてきて確認したいと思います。

$ helm pull stable/wordpress
$ tar zxvf wordpress-9.3.21.tgz
$ tree wordpress
wordpress
├── charts
│   └── mariadb
│       ├── Chart.yaml
│       ├── files
│       │   └── docker-entrypoint-initdb.d
│       │       └── README.md
│       ├── OWNERS
│       ├── README.md
│       ├── templates
│       │   ├── _helpers.tpl
│       │   ├── initialization-configmap.yaml
│       │   ├── master-configmap.yaml
│       │   ├── master-pdb.yaml
│       │   ├── master-statefulset.yaml
│       │   ├── master-svc.yaml
│       │   ├── NOTES.txt
│       │   ├── rolebinding.yaml
│       │   ├── role.yaml
│       │   ├── secrets.yaml
│       │   ├── serviceaccount.yaml
│       │   ├── servicemonitor.yaml
│       │   ├── slave-configmap.yaml
│       │   ├── slave-pdb.yaml
│       │   ├── slave-statefulset.yaml
│       │   ├── slave-svc.yaml
│       │   ├── test-runner.yaml
│       │   └── tests.yaml
│       ├── values-production.yaml
│       ├── values.schema.json
│       └── values.yaml
├── Chart.yaml
├── README.md
├── requirements.lock
├── requirements.yaml
├── templates
│   ├── deployment.yaml
│   ├── externaldb-secrets.yaml
│   ├── _helpers.tpl
│   ├── ingress.yaml
│   ├── NOTES.txt
│   ├── pvc.yaml
│   ├── secrets.yaml
│   ├── servicemonitor.yaml
│   ├── svc.yaml
│   ├── tests
│   │   └── test-mariadb-connection.yaml
│   └── tls-secrets.yaml
├── values.schema.json
└── values.yaml

mariadbに依存していることがわかります。

$ helm dependencies list wordpress
NAME    VERSION REPOSITORY                                              STATUS  
mariadb 7.x.x   https://kubernetes-charts.storage.googleapis.com/       unpacked

この情報はどこから取ってきているのかというと、YAMLのdependencies:以下です。上記のチャートですと requirements.yamlに書かれています。

requirements.yaml

dependencies:
  - name: mariadb
    version: 7.x.x
    repository: https://kubernetes-charts.storage.googleapis.com/
    condition: mariadb.enabled
    tags:
      - wordpress-database

そして、dependencies:以下に定義されたチャートは、 charts/以下に実態ファイルがあります。先程のtreeの結果にも、eksdemo/charts/mariadbというディレクトリがありますよね。

また、helm dependencies updatedependencies:以下の定義に基づきcharts/以下のチャートを更新することができます。

$ helm dependencies update wordpress
Getting updates for unmanaged Helm repositories...
...Unable to get an update from the "https://kubernetes-charts.storage.googleapis.com/" chart repository:
        failed to fetch https://kubernetes-charts.storage.googleapis.com/index.yaml : 403 Forbidden

失敗しましたね…調べたところによると、mariadbチャート配布元のhttps://kubernetes-charts.storage.googleapis.com/リポジトリが廃止され、代わりにhttps://charts.helm.sh/stableを使う必要があるようです。というわけで先程のYAMLを更新します。

requirements.yaml

dependencies:
  - name: mariadb
    version: 7.x.x
-    repository: https://kubernetes-charts.storage.googleapis.com/
+    repository: https://charts.helm.sh/stable
    condition: mariadb.enabled
    tags:
      - wordpress-database

もう一度helm dependencies updateしてみます。

$ helm dependencies update wordpress
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "eks" chart repository
...Successfully got an update from the "stable" chart repository
...Successfully got an update from the "bitnami" chart repository
Update Complete. ⎈Happy Helming!⎈
Saving 1 charts
Downloading mariadb from repo https://charts.helm.sh/stable
Deleting outdated charts

今度は成功したようです。成功した場合requirements.lockファイルが更新されます。

requirements.lock

dependencies:
- name: mariadb
  repository: https://charts.helm.sh/stable
  version: 7.3.14
digest: sha256:a011b4950ffc35f94724fd8a1d7c99f8ce7b26cd9806cd00a6454f5ee3ee5b70
generated: "2021-01-16T12:41:09.122145628Z"

バージョン7.3.14がインストールされているようですね。

試しにdependencies:のバージョンを変更してみましょう。

requirements.yaml

dependencies:
  - name: mariadb
-    version: 7.x.x
+    version: 6.x.x
    repository: https://charts.helm.sh/stable
    condition: mariadb.enabled
    tags:
      - wordpress-database

その後再度helm dependencies update wordpressしてみると、requirements.lockファイルの中身が更新されていることが確認できました。

requirements.lock

dependencies:
- name: mariadb
  repository: https://charts.helm.sh/stable
  version: 6.13.0
digest: sha256:739bdb805fe539dd522fdc639e44af2bed8ca0fda36ee418a960405f9634d61b
generated: "2021-01-17T12:02:38.579708892Z"

最後のサブコマンド helm dependencies buildは以下のようなコマンドです。

  • 前述のロックファイルが無い時 → helm dependencies updateと同じ挙動
  • ロックファイルがある時 → YAMLファイルのdependencies:以下に書かれているバージョンではなく、ロックファイルに書かれているバージョンを使って依存関係のチャートをインストールする

  • Helm Dependency

env

helm client environment information

Helmが使う環境変数一覧を出力します。

$ helm env
HELM_BIN="helm"
HELM_CACHE_HOME="/home/ec2-user/.cache/helm"
HELM_CONFIG_HOME="/home/ec2-user/.config/helm"
HELM_DATA_HOME="/home/ec2-user/.local/share/helm"
HELM_DEBUG="false"
HELM_KUBEAPISERVER=""
HELM_KUBEASGROUPS=""
HELM_KUBEASUSER=""
HELM_KUBECAFILE=""
HELM_KUBECONTEXT=""
HELM_KUBETOKEN=""
HELM_MAX_HISTORY="10"
HELM_NAMESPACE="default"
HELM_PLUGINS="/home/ec2-user/.local/share/helm/plugins"
HELM_REGISTRY_CONFIG="/home/ec2-user/.config/helm/registry.json"
HELM_REPOSITORY_CACHE="/home/ec2-user/.cache/helm/repository"
HELM_REPOSITORY_CONFIG="/home/ec2-user/.config/helm/repositories.yaml"

get

download extended information of a named release

リリースについての 様々な詳細方法を取得するコマンドです。以下サブコマンドがあります。

Available Commands:
  all         download all information for a named release
  hooks       download all hooks for a named release
  manifest    download the manifest for a named release
  notes       download the notes for a named release
  values      download the values file for a named release

EKS Workshopでは Bitnamiリポジトリのnginxチャートからmywebserverという名前のリリースを作成します。このリリースに対してgetコマンドを使ってみます。

$ helm get hooks mywebserver

$ helm get manifest mywebserver
---
# Source: nginx/templates/server-block-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: mywebserver-nginx-server-block
  labels:
    app.kubernetes.io/name: nginx
    helm.sh/chart: nginx-8.3.0
    app.kubernetes.io/instance: mywebserver
    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: mywebserver-nginx
  labels:
    app.kubernetes.io/name: nginx
    helm.sh/chart: nginx-8.3.0
    app.kubernetes.io/instance: mywebserver
    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: mywebserver
---
# Source: nginx/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mywebserver-nginx
  labels:
    app.kubernetes.io/name: nginx
    helm.sh/chart: nginx-8.3.0
    app.kubernetes.io/instance: mywebserver
    app.kubernetes.io/managed-by: Helm
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: nginx
      app.kubernetes.io/instance: mywebserver
  template:
    metadata:
      labels:
        app.kubernetes.io/name: nginx
        helm.sh/chart: nginx-8.3.0
        app.kubernetes.io/instance: mywebserver
        app.kubernetes.io/managed-by: Helm
    spec:
      
      affinity:
        podAffinity:
          
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
            - podAffinityTerm:
                labelSelector:
                  matchLabels:
                    app.kubernetes.io/name: nginx
                    app.kubernetes.io/instance: mywebserver
                namespaces:
                  - default
                topologyKey: kubernetes.io/hostname
              weight: 1
        nodeAffinity:
          
      containers:
        - name: nginx
          image: docker.io/bitnami/nginx:1.19.6-debian-10-r21
          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: mywebserver-nginx-server-block
            items:
              - key: server-blocks-paths.conf
                path: server-blocks-paths.conf
                
$ helm get notes mywebserver
NOTES:
** Please be patient while the chart is being deployed **

NGINX can be accessed through the following DNS name from within your cluster:

    mywebserver-nginx.default.svc.cluster.local (port 80)

To access NGINX from outside the cluster, follow the steps below:

1. Get the NGINX URL by running these commands:

  NOTE: It may take a few minutes for the LoadBalancer IP to be available.
        Watch the status with: 'kubectl get svc --namespace default -w mywebserver-nginx'

    export SERVICE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].port}" services mywebserver-nginx)
    export SERVICE_IP=$(kubectl get svc --namespace default mywebserver-nginx -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
    echo "http://${SERVICE_IP}:${SERVICE_PORT}"
    
$ helm get values mywebserver
USER-SUPPLIED VALUES:
null

リリースの中身を確認するのに便利ですね。

個人的に便利だなーと感じたのは--revisionオプションです。helm historyで確認できる各リビジョン時のリリースの中身がどうなっていたのかを知ることができます。

help

Help about any command

サブコマンドを教えてくれるだけかと思いきや、環境変数の解説なども表示してくれるんですね。

$ helm help
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, postgres   |
| $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 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
  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:
      --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-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 "/home/ec2-user/.config/helm/registry.json")
      --repository-cache string     path to the file containing cached repository indexes (default "/home/ec2-user/.cache/helm/repository")
      --repository-config string    path to the file containing repository names and URLs (default "/home/ec2-user/.config/helm/repositories.yaml")

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

history

fetch release history

リリースにはリビジョンの概念があります。このコマンドでは特定のリリースのリビジョン履歴が確認できます。

インストールしたばっかりのリリースのリビジョンは当然1だけです。

$ helm install mywebserver bitnami/nginx
(省略)
$ helm history mywebserver
REVISION        UPDATED                         STATUS          CHART           APP VERSION     DESCRIPTION     
1               Tue Jan 19 12:06:58 2021        deployed        nginx-8.3.0     1.19.6          Install complete

upgradeしてみます。

$ helm upgrade -f ./mywebserver.yaml mywebserver bitnami/nginx                                                                                                                                      
Release "mywebserver" has been upgraded. Happy Helming!
NAME: mywebserver
LAST DEPLOYED: Tue Jan 19 12:22:25 2021
NAMESPACE: default
STATUS: deployed
REVISION: 2
TEST SUITE: None
NOTES:
** Please be patient while the chart is being deployed **

NGINX can be accessed through the following DNS name from within your cluster:

    mywebserver-nginx.default.svc.cluster.local (port 80)

To access NGINX from outside the cluster, follow the steps below:

1. Get the NGINX URL by running these commands:

  NOTE: It may take a few minutes for the LoadBalancer IP to be available.
        Watch the status with: 'kubectl get svc --namespace default -w mywebserver-nginx'

    export SERVICE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].port}" services mywebserver-nginx)
    export SERVICE_IP=$(kubectl get svc --namespace default mywebserver-nginx -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
    echo "http://${SERVICE_IP}:${SERVICE_PORT}"

もう一度 helm historyしてみます。

$ helm history mywebserver
REVISION        UPDATED                         STATUS          CHART           APP VERSION     DESCRIPTION     
1               Tue Jan 19 12:06:58 2021        superseded      nginx-8.3.0     1.19.6          Install complete
2               Tue Jan 19 12:22:25 2021        deployed        nginx-8.3.0     1.19.6          Upgrade complete

STATUS列に注目ください。先程はdeployedステータスだったリビジョン1がsuperseded(=取って代わられた)になり、代わりにリビジョン2のステータスがdeployedになっています。

また、rollbackコマンドですぐに元のリビジョンに戻せます。

$ helm rollback mywebserver 1
Rollback was a success! Happy Helming!
$ helm history mywebserver
REVISION        UPDATED                         STATUS          CHART           APP VERSION     DESCRIPTION     
1               Tue Jan 19 12:06:58 2021        superseded      nginx-8.3.0     1.19.6          Install complete
2               Tue Jan 19 12:22:25 2021        superseded      nginx-8.3.0     1.19.6          Upgrade complete
3               Tue Jan 19 12:28:05 2021        deployed        nginx-8.3.0     1.19.6          Rollback to 1

リビジョン1が再びdeployedになるわけではなく、1と同じ内容のリビジョン3が作られそのステータスがdeployedになります。

install

install a chart

リポジトリからチャートをダウンロードしてきて、リリースを作成します。

$ helm install mywebserver bitnami/nginx
NAME: mywebserver
LAST DEPLOYED: Sun Jan 24 12:46:14 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
** Please be patient while the chart is being deployed **

NGINX can be accessed through the following DNS name from within your cluster:

    mywebserver-nginx.default.svc.cluster.local (port 80)

To access NGINX from outside the cluster, follow the steps below:

1. Get the NGINX URL by running these commands:

  NOTE: It may take a few minutes for the LoadBalancer IP to be available.
        Watch the status with: 'kubectl get svc --namespace default -w mywebserver-nginx'

    export SERVICE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].port}" services mywebserver-nginx)
    export SERVICE_IP=$(kubectl get svc --namespace default mywebserver-nginx -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
    echo "http://${SERVICE_IP}:${SERVICE_PORT}"

lint

examine a chart for possible issues

チャートの構文チェックを行ないます。

$ helm create lintexample
Creating lintexample
$ helm lint lintexample
==> Linting lintexample
[INFO] Chart.yaml: icon is recommended

1 chart(s) linted, 0 chart(s) failed

icon is recommendedという指摘が入りましたね。追加してみます。

lintexample/Chart.yaml

apiVersion: v2
name: lintexample
description: A Helm chart for Kubernetes

# A chart can be either an 'application' or a 'library' chart.
#
# Application charts are a collection of templates that can be packaged into versioned archives
# to be deployed.
#
# Library charts provide useful utilities or functions for the chart developer. They're included as
# a dependency of application charts to inject those utilities and functions into the rendering
# pipeline. Library charts do not define any templates and therefore cannot be deployed.
type: application

# This is the chart version. This version number should be incremented each time you make changes
# to the chart and its templates, including the app version.
# Versions are expected to follow Semantic Versioning (https://semver.org/)
version: 0.1.0

# This is the version number of the application being deployed. This version number should be
# incremented each time you make changes to the application. Versions are not expected to
# follow Semantic Versioning. They should reflect the version the application is using.
# It is recommended to use it with quotes.
appVersion: "1.16.0"

icon: https://dev.classmethod.jp/_nuxt/img/91723c1.svg

もう一度lintを実行するとiconの指摘はされなくなりました。

$ helm lint lintexample
==> Linting lintexample

1 chart(s) linted, 0 chart(s) failed

list

list releases

リリースの一覧を出力します。

$ helm list
NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART           APP VERSION
mywebserver     default         1               2021-01-24 12:46:14.506322101 +0000 UTC deployed        nginx-8.3.0     1.19.6

デフォルトでは現在のネームスペースに存在するリリースのみを出力することにご注意ください。-n もしくは--namespaceオプションで別ネームスペース上のリリースも確認できます。 -A--all-namespaces オプションを使うと全ネームスペース上のリリースを一挙確認もできます。フィルタリングとかソートのオプションも色々ありますが、まだそこまで活用したことないです。。

package

package a chart directory into a chart archive

チャートを圧縮ファイルを作成します。圧縮ファイルはリポジトリを作成する際に使うそうです。

$ helm package wordpress
Successfully packaged chart and saved it to: /home/ec2-user/environment/wordpress-9.0.3.tgz

plugin

install, list, or uninstall Helm plugins

HelmにはHelm pluginというアドオンツール群が存在します。この helm pluginコマンドはその管理を担います。以下4つのサブコマンドが存在します。

Available Commands:
  install     install one or more Helm plugins
  list        list installed Helm plugins
  uninstall   uninstall one or more Helm plugins
  update      update one or more Helm plugins

helm diffというプラグインを例に説明します。

最初は何のプラグインもありません。

$ helm plugin list
NAME    VERSION DESCRIPTION

helm diffをインストールしてみます。

$ helm plugin install https://github.com/databus23/helm-diff
Downloading https://github.com/databus23/helm-diff/releases/download/v3.1.3/helm-diff-linux.tgz
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   643  100   643    0     0   2248      0 --:--:-- --:--:-- --:--:--  2248
100 14.9M  100 14.9M    0     0  4348k      0  0:00:03  0:00:03 --:--:-- 6071k
Preparing to install into /home/ec2-user/.local/share/helm/plugins/helm-diff
helm-diff installed into /home/ec2-user/.local/share/helm/plugins/helm-diff/helm-diff

The Helm Diff Plugin

(割愛)

Additional help topics:
  diff          

Use "diff [command] --help" for more information about a command.
Installed plugin: diff
$ helm plugin list
NAME    VERSION DESCRIPTION                           
diff    3.1.3   Preview helm upgrade changes as a diff

これでhelm diffコマンドが使えるようになります。

アンインストールします。

$ helm plugin uninstall diff
Uninstalled plugin: diff
$ helm plugin list
NAME    VERSION DESCRIPTION

pull

download a chart from a repository and (optionally) unpack it in local directory

helm dependencyの項ですでにやっていますが、リポジトリからチャートをダウンロードしてくるコマンドです。

$ helm pull stable/wordpress
$ tar zxvf wordpress-9.3.21.tgz
$ tree wordpress
wordpress
├── charts
│   └── mariadb
│       ├── Chart.yaml
│       ├── files
│       │   └── docker-entrypoint-initdb.d
│       │       └── README.md
│       ├── OWNERS
│       ├── README.md
│       ├── templates
│       │   ├── _helpers.tpl
│       │   ├── initialization-configmap.yaml
│       │   ├── master-configmap.yaml
│       │   ├── master-pdb.yaml
│       │   ├── master-statefulset.yaml
│       │   ├── master-svc.yaml
│       │   ├── NOTES.txt
│       │   ├── rolebinding.yaml
│       │   ├── role.yaml
│       │   ├── secrets.yaml
│       │   ├── serviceaccount.yaml
│       │   ├── servicemonitor.yaml
│       │   ├── slave-configmap.yaml
│       │   ├── slave-pdb.yaml
│       │   ├── slave-statefulset.yaml
│       │   ├── slave-svc.yaml
│       │   ├── test-runner.yaml
│       │   └── tests.yaml
│       ├── values-production.yaml
│       ├── values.schema.json
│       └── values.yaml
├── Chart.yaml
├── README.md
├── requirements.lock
├── requirements.yaml
├── templates
│   ├── deployment.yaml
│   ├── externaldb-secrets.yaml
│   ├── _helpers.tpl
│   ├── ingress.yaml
│   ├── NOTES.txt
│   ├── pvc.yaml
│   ├── secrets.yaml
│   ├── servicemonitor.yaml
│   ├── svc.yaml
│   ├── tests
│   │   └── test-mariadb-connection.yaml
│   └── tls-secrets.yaml
├── values.schema.json
└── values.yaml

上記は圧縮形式でダウンロードして後から解凍していますが、--untarオプションを使えば解凍状態でダウンロードもできます。(今知りました。) --untardirで解凍先ディレクトリも指定できます。

repo

add, list, remove, update, and index chart repositories

リポジトリを操作するコマンドです。以下サブコマンドがあります。

Available Commands:
  add         add a chart repository
  index       generate an index file given a directory containing packaged charts
  list        list chart repositories
  remove      remove one or more chart repositories
  update      update information of available charts locally from chart repositories

一番使うのはaddでしょうか。

add

$ helm repo add bitnami https://charts.bitnami.com/bitnami
"bitnami" has been added to your repositories

list

$ helm repo list
NAME    URL                               
stable  https://charts.helm.sh/stable     
eks     https://aws.github.io/eks-charts  
bitnami https://charts.bitnami.com/bitnami

update

$ helm repo update
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "eks" chart repository
...Successfully got an update from the "stable" chart repository
...Successfully got an update from the "bitnami" chart repository
Update Complete. ⎈Happy Helming!⎈

remove

$ helm repo remove bitnami
"bitnami" has been removed from your repositories

上記コマンド群はリポジトリを利用する際に使うものですが、次のindexはリポジトリを作成する際に使います。

リポジトリにはインデックスファイルというYAMLファイルを置く必要があります。YAMLの中身はリポジトリに格納されているチャートのメタデータ一覧です。このコマンドはそのインデックスファイルを自動作成してくれるコマンドです。

index

$ helm pull stable/wordpress --untar
$ helm repo index .
(カレントディレクトリにindex.yamlが作成される)
$ cat index.yaml                                                                 
apiVersion: v1
entries:
  wordpress:
  - apiVersion: v1
    appVersion: 5.3.2
    created: "2021-01-27T05:52:03.289919598Z"
    dependencies:
    - condition: mariadb.enabled
      name: mariadb
      repository: https://kubernetes-charts.storage.googleapis.com/
      tags:
      - wordpress-database
      version: 7.x.x
    deprecated: true
    description: DEPRECATED Web publishing platform for building blogs and websites.
    digest: b83c4d4009d3a37298a13e75afa1a16f1826b3f84504d1201c1bd7e301501f44
    home: http://www.wordpress.com/
    icon: https://bitnami.com/assets/stacks/wordpress/img/wordpress-stack-220x234.png
    keywords:
    - wordpress
    - cms
    - blog
    - http
    - web
    - application
    - php
    name: wordpress
    sources:
    - https://github.com/bitnami/bitnami-docker-wordpress
    urls:
    - wordpress-9.0.3.tgz
    version: 9.0.3
generated: "2021-01-27T05:52:03.285432454Z"

rollback

roll back a release to a previous revision

helm historyの項で説明したとおり、リリースを過去のリビジョンに巻き戻すことができるコマンドです。 historyの欄をご覧ください。

search for a keyword in charts

ふたつサブコマンドがあります。

Available Commands:
  hub         search for charts in the Artifact Hub or your own hub instance
  repo        search repositories for a keyword in charts

helm search repoはリポジトリ内を検索してチャートを探します。検索対象のリポジトリはhelm repo addしてるリポジトリつまりhelm repo listで表示されるリポジトリ達です。

search repo

$ helm search repo nginx
NAME                                    CHART VERSION   APP VERSION     DESCRIPTION                                       
bitnami/nginx                           8.4.1           1.19.6          Chart for the nginx server                        
bitnami/nginx-ingress-controller        7.1.3           0.43.0          Chart for the nginx Ingress controller            
stable/nginx-ingress                    1.41.3          v0.34.1         DEPRECATED! An nginx Ingress controller that us...
stable/nginx-ldapauth-proxy             0.1.6           1.13.5          DEPRECATED - nginx proxy with ldapauth            
stable/nginx-lego                       0.3.1                           Chart for nginx-ingress-controller and kube-lego  
bitnami/kong                            3.3.2           2.3.1           Kong is a scalable, open source API layer (aka ...
stable/gcloud-endpoints                 0.1.2           1               DEPRECATED Develop, deploy, protect and monitor...

helm serach hubはもっと広範囲に、Artifact HUB上のチャートを検索します。Artifact HUBはCloud Native Computing Foundation(CNCF)が運営している、Helmチャート含む様々なパッケージを検索、配布などするWebサイトです。

search hub

$ helm search hub nginx -o yaml
- app_version: ""
  description: An NGINX HTTP server
  url: https://artifacthub.io/packages/helm/wiremind/nginx
  version: 2.1.1
- app_version: 1.19.6
  description: Chart for the nginx server
  url: https://artifacthub.io/packages/helm/bitnami/nginx
  version: 8.4.1
- app_version: 1.16.0
  description: A NGINX Docker Community based Helm chart for Kubernetes
  url: https://artifacthub.io/packages/helm/mirantis/nginx
  version: 0.1.0
- app_version: 1.17.9
  description: |-
    Helm chart to deploy [nginx](https://www.nginx.com).

    Chart supports environment variables inside of the nginx.conf file.
  url: https://artifacthub.io/packages/helm/slamdev/nginx
  version: 0.0.11
- app_version: latest
  description: A chart to do nginx things
  url: https://artifacthub.io/packages/helm/cocainefarm/nginx
  version: 1.0.1
- app_version: ""
  description: Simple nginx deployment usable for deploying proxies or small sites.
  url: https://artifacthub.io/packages/helm/t3n/nginx
  version: 0.1.1
- app_version: 0.43.0
  description: Ingress controller for Kubernetes using NGINX as a reverse proxy and load balancer
  url: https://artifacthub.io/packages/helm/ingress-nginx/ingress-nginx
  version: 3.21.0
- app_version: 1.10.0
  description: NGINX Ingress Controller
  url: https://artifacthub.io/packages/helm/nginx/nginx-ingress
  version: 0.8.0
- app_version: 0.29.0
  description: An nginx Ingress controller that uses ConfigMap to store the nginx configuration.
  url: https://artifacthub.io/packages/helm/hkube/nginx-ingress
  version: 1.31.1002
- app_version: 0.0.0-edge
  description: NGINX Ingress Controller
  url: https://artifacthub.io/packages/helm/nginx-edge/nginx-ingress
  version: 0.0.0-edge
- app_version: 0.43.0
  description: Ingress controller for Kubernetes using NGINX as a reverse proxy and load balancer
  url: https://artifacthub.io/packages/helm/wener/ingress-nginx
  version: 3.21.0
- app_version: ""
  description: A Helm chart for Nginx Ingress
  url: https://artifacthub.io/packages/helm/cloudposse/nginx-ingress
  version: 0.1.8
- app_version: latest
  description: A Dockerfile for nginx-rtmp-module + FFmpeg from source with basic settings for streaming HLS. Built on Alpine Linux
  url: https://artifacthub.io/packages/helm/cocainefarm/nginx-rtmp
  version: 0.7.0
- app_version: "1.1"
  description: A Helm chart for installing a simple nginx
  url: https://artifacthub.io/packages/helm/newrelic/simple-nginx
  version: 1.1.1
- app_version: ""
  description: A Helm chart for nginx-default-backend to be used by nginx-ingress controller
  url: https://artifacthub.io/packages/helm/cloudposse/nginx-default-backend
  version: 0.5.0
- app_version: 0.43.0
  description: Chart for the nginx Ingress controller
  url: https://artifacthub.io/packages/helm/bitnami/nginx-ingress-controller
  version: 7.1.3
- app_version: 0.1.2
  description: A Simple Web service Chart
  url: https://artifacthub.io/packages/helm/pnnl-miscscripts/nginx-app
  version: 0.1.2
- app_version: 1.13.5-alpine
  description: A Helm chart for Kubernetes
  url: https://artifacthub.io/packages/helm/choerodon/nginx-files-server
  version: 0.1.0
- app_version: 2.5.0
  description: A Demo application for the logging-operator
  url: https://artifacthub.io/packages/helm/banzaicloud-stable/nginx-logging-demo
  version: 2.5.0
- app_version: 2.5.0
  description: A Demo application for the logging-operator AWS CloudWatch backend
  url: https://artifacthub.io/packages/helm/banzaicloud-stable/nginx-logging-cw-demo
  version: 2.5.0
- app_version: 2.5.0
  description: A Demo application for the logging-operator
  url: https://artifacthub.io/packages/helm/banzaicloud-stable/nginx-logging-es-demo
  version: 2.5.0
- app_version: 2.5.0
  description: A Helm chart for Kubernetes
  url: https://artifacthub.io/packages/helm/banzaicloud-stable/nginx-logging-kafka-demo
  version: 2.5.0
- app_version: 2.5.0
  description: A Demo application for the logging-operator
  url: https://artifacthub.io/packages/helm/banzaicloud-stable/nginx-logging-loki-demo
  version: 2.5.0
- app_version: ""
  description: A Helm chart that provides a maintenance backend to be used by nginx-ingress controller
  url: https://artifacthub.io/packages/helm/cloudposse/fail-whale
  version: 0.1.1
- app_version: 1.6.1
  description: Flagger is a progressive delivery operator for Kubernetes
  url: https://artifacthub.io/packages/helm/flagger/flagger
  version: 1.6.1
- app_version: 2.3.1
  description: Kong is a scalable, open source API layer (aka API gateway or API middleware) that runs in front of any RESTful API. Extra functionalities beyond the core platform are extended through plugins. Kong is built on top of reliable technologies like NGINX and provides an easy-to-use RESTful API to operate and configure the system.
  url: https://artifacthub.io/packages/helm/bitnami/kong
  version: 3.3.2
- app_version: v0.0.1
  description: A Helm chart for deployoing ORY Oathkeeper Rule Controller in Kubernetes
  url: https://artifacthub.io/packages/helm/ory/maester
  version: 0.0.17
- app_version: v0.38.4-beta.1
  description: A Helm chart for deploying ORY Oathkeeper in Kubernetes
  url: https://artifacthub.io/packages/helm/ory/oathkeeper
  version: 0.5.2
- app_version: v0.1.0
  description: A Helm chart for deploying ORY Oathkeeper Rule Controller in Kubernetes
  url: https://artifacthub.io/packages/helm/ory/oathkeeper-maester
  version: 0.5.2
- app_version: 0.17.3
  description: An SSO and OAuth login solution for nginx using the auth_request module
  url: https://artifacthub.io/packages/helm/halkeye/vouch
  version: 1.0.0

show

show information of a chart

チャートの情報を取得します。サブコマンドは以下です。

Available Commands:
  all         show all information of the chart
  chart       show the chart's definition
  readme      show the chart's README
  values      show the chart's values

helm getと混同しそうになりますが、 helm getリリースhelm showチャートの情報を取得します。

readme

$ helm show readme bitnami/nginx
(https://github.com/bitnami/charts/tree/master/bitnami/nginxの内容がズラーッと表示されます)

chart

$ helm show chart bitnami/nginx
annotations:
  category: Infrastructure
apiVersion: v2
appVersion: 1.19.6
dependencies:
- name: common
  repository: https://charts.bitnami.com/bitnami
  tags:
  - bitnami-common
  version: 1.x.x
description: Chart for the nginx server
home: https://github.com/bitnami/charts/tree/master/bitnami/nginx
icon: https://bitnami.com/assets/stacks/nginx/img/nginx-stack-220x234.png
keywords:
- nginx
- http
- web
- www
- reverse proxy
maintainers:
- email: containers@bitnami.com
  name: Bitnami
name: nginx
sources:
- https://github.com/bitnami/bitnami-docker-nginx
- http://www.nginx.org
version: 8.4.1

values

$ helm show values bitnami/nginx
(https://github.com/bitnami/charts/blob/master/bitnami/nginx/values.yamlの情報が表示されます)

show valuesは便利ですねー。今後使いたいと思います。

status

display the status of the named release

リリースのステータスを取得します。

$ helm install mywebserver bitnami/nginx
$ helm status mywebserver
NAME: mywebserver
LAST DEPLOYED: Wed Jan 27 09:49:48 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
** Please be patient while the chart is being deployed **

NGINX can be accessed through the following DNS name from within your cluster:

    mywebserver-nginx.default.svc.cluster.local (port 80)

To access NGINX from outside the cluster, follow the steps below:

1. Get the NGINX URL by running these commands:

  NOTE: It may take a few minutes for the LoadBalancer IP to be available.
        Watch the status with: 'kubectl get svc --namespace default -w mywebserver-nginx'

    export SERVICE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].port}" services mywebserver-nginx)
    export SERVICE_IP=$(kubectl get svc --namespace default mywebserver-nginx -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
    echo "http://${SERVICE_IP}:${SERVICE_PORT}"

helm getと混同しそうですが、こっちはその名のとおりステータス的な情報の取得で、getの方がより細かい情報を取れる感じです。

template

locally render templates

チャートからマニフェストファイルを作成して出力します。その際、チャートの動的な部分はvalueファイルの値を使って置換されます。つまり出来上がったマニフェストファイルが確認できるということですね。

EKS WorkshopDeploy Example Microservices Using Helmの項を例に挙げます。ここまでやってから helm templateしてみます。

$ helm template ~/environment/eksdemo
---
# Source: eksdemo/templates/service/crystal.yaml
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-crystal
spec:
  selector:
    app: ecsdemo-crystal
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000
---
# Source: eksdemo/templates/service/frontend.yaml
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-frontend
spec:
  selector:
    app: ecsdemo-frontend
  type: LoadBalancer
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000
---
# Source: eksdemo/templates/service/nodejs.yaml
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-nodejs
spec:
  selector:
    app: ecsdemo-nodejs
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000
---
# Source: eksdemo/templates/deployment/crystal.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecsdemo-crystal
  labels:
    app: ecsdemo-crystal
  namespace: default
spec:
  replicas: 3
  selector:
    matchLabels:
      app: ecsdemo-crystal
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: ecsdemo-crystal
    spec:
      containers:
      - image: brentley/ecsdemo-crystal:latest
        imagePullPolicy: Always
        name: ecsdemo-crystal
        ports:
        - containerPort: 3000
          protocol: TCP
---
# Source: eksdemo/templates/deployment/frontend.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecsdemo-frontend
  labels:
    app: ecsdemo-frontend
  namespace: default
spec:
  replicas: 3
  selector:
    matchLabels:
      app: ecsdemo-frontend
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: ecsdemo-frontend
    spec:
      containers:
      - image: brentley/ecsdemo-frontend:latest
        imagePullPolicy: Always
        name: ecsdemo-frontend
        ports:
        - containerPort: 3000
          protocol: TCP
        env:
        - name: CRYSTAL_URL
          value: "http://ecsdemo-crystal.default.svc.cluster.local/crystal"
        - name: NODEJS_URL
          value: "http://ecsdemo-nodejs.default.svc.cluster.local/"
---
# Source: eksdemo/templates/deployment/nodejs.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecsdemo-nodejs
  labels:
    app: ecsdemo-nodejs
  namespace: default
spec:
  replicas: 3
  selector:
    matchLabels:
      app: ecsdemo-nodejs
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: ecsdemo-nodejs
    spec:
      containers:
      - image: brentley/ecsdemo-nodejs:latest
        imagePullPolicy: Always
        name: ecsdemo-nodejs
        ports:
        - containerPort: 3000
          protocol: TCP

別のvalueファイルを作って、それをtemplateに渡して結果を見てみましょう。value2.yamlを作ります。ハイライトにしたreplicaの部分が元のvalueファイルとの相違点です。

value2.yaml

# Default values for eksdemo.
# This is a YAML-formatted file.
# Declare variables to be passed into your templates.

# Release-wide Values
replicas: 1
version: 'latest'

# Service Specific Values
nodejs:
  image: brentley/ecsdemo-nodejs
crystal:
  image: brentley/ecsdemo-crystal
frontend:
  image: brentley/ecsdemo-frontend

-f オプションで食わせるvalueファイルを変更できます。valueファイルの相違点が反映されていることがわかります。(ハイライト部分)

$ helm template ~/environment/eksdemo -f ~/environment/eksdemo/values2.yaml 
---
# Source: eksdemo/templates/service/crystal.yaml
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-crystal
spec:
  selector:
    app: ecsdemo-crystal
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000
---
# Source: eksdemo/templates/service/frontend.yaml
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-frontend
spec:
  selector:
    app: ecsdemo-frontend
  type: LoadBalancer
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000
---
# Source: eksdemo/templates/service/nodejs.yaml
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-nodejs
spec:
  selector:
    app: ecsdemo-nodejs
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000
---
# Source: eksdemo/templates/deployment/crystal.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecsdemo-crystal
  labels:
    app: ecsdemo-crystal
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ecsdemo-crystal
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: ecsdemo-crystal
    spec:
      containers:
      - image: brentley/ecsdemo-crystal:latest
        imagePullPolicy: Always
        name: ecsdemo-crystal
        ports:
        - containerPort: 3000
          protocol: TCP
---
# Source: eksdemo/templates/deployment/frontend.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecsdemo-frontend
  labels:
    app: ecsdemo-frontend
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ecsdemo-frontend
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: ecsdemo-frontend
    spec:
      containers:
      - image: brentley/ecsdemo-frontend:latest
        imagePullPolicy: Always
        name: ecsdemo-frontend
        ports:
        - containerPort: 3000
          protocol: TCP
        env:
        - name: CRYSTAL_URL
          value: "http://ecsdemo-crystal.default.svc.cluster.local/crystal"
        - name: NODEJS_URL
          value: "http://ecsdemo-nodejs.default.svc.cluster.local/"
---
# Source: eksdemo/templates/deployment/nodejs.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecsdemo-nodejs
  labels:
    app: ecsdemo-nodejs
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ecsdemo-nodejs
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: ecsdemo-nodejs
    spec:
      containers:
      - image: brentley/ecsdemo-nodejs:latest
        imagePullPolicy: Always
        name: ecsdemo-nodejs
        ports:
        - containerPort: 3000
          protocol: TCP

test

run tests for a release

リリースのテストを実行します。

テストの内容は、templates/以下に書く必要があります。複数のファイルに分割もできますし、他と区別するため templates/tests以下に書くこともできます。Jobのマニフェストを書きます。以下アノテーションを付ける必要があります。

metadata:
  annotations:
    "helm.sh/hook": test

指定したイメージからコンテナを立ち上げ、指定したコマンドを実行してエラーが出なかったらテスト成功です。

EKSWorkshopの Deploy Example Microservices Using Helmを例にして、テストを書いてみたいと思います。frontend podからcrystal serviceへの疎通を確認します。

~/environment/eksdemo/templates/tests/frontend.yaml

apiVersion: batch/v1
kind: Job
metadata:
  name: ecsdemo-frontend-test
  annotations:
    "helm.sh/hook": test
spec:
  template:
    metadata:
      labels:
        app: ecsdemo-frontend
    spec:
      containers:
      - image: {{ .Values.frontend.image }}:{{ .Values.version }}
        name: ecsdemo-frontend-test
        ports:
        - containerPort: 3000
          protocol: TCP
        env:
        - name: CRYSTAL_URL
          value: "http://ecsdemo-crystal.default.svc.cluster.local/crystal"
        - name: NODEJS_URL
          value: "http://ecsdemo-nodejs.default.svc.cluster.local/"
        command: ["curl"]
        args: ["$(CRYSTAL_URL)"] 
      restartPolicy: Never

リリースを更新します。

$ helm upgrade workshop ~/environment/eksdemo
Release "workshop" has been upgraded. Happy Helming!
NAME: workshop
LAST DEPLOYED: Thu Jan 28 07:22:47 2021
NAMESPACE: default
STATUS: deployed
REVISION: 2

テスト実行します。

$ helm test workshop
NAME: workshop
LAST DEPLOYED: Thu Jan 28 07:22:47 2021
NAMESPACE: default
STATUS: deployed
REVISION: 2
TEST SUITE:     ecsdemo-frontend-test
Last Started:   Thu Jan 28 07:23:27 2021
Last Completed: Thu Jan 28 07:23:31 2021
Phase:          Succeeded

uninstall

uninstall a release

そのまんまですが、リリースをアンインストールします。

$ helm uninstall workshop
release "workshop" uninstalled

upgrade

upgrade a release

最新版のチャートを取得してリリースを更新します。

$ helm upgrade workshop ~/environment/eksdemo
Release "workshop" has been upgraded. Happy Helming!
NAME: workshop
LAST DEPLOYED: Thu Jan 28 07:22:47 2021
NAMESPACE: default
STATUS: deployed
REVISION: 2

--versionオプションで最新版ではなく任意のバージョンで更新することもできます。またhelm installと同様 -fでvalueファイルを指定もできます。

verify

verify that a chart at the given path has been signed and is valid

チャートが改ざんされたものでないかの検証を行ないます。検証は、helm package時に --signオプションを使って圧縮ファイルを作成したチャートに対してのみ実行可能です。

PGP鍵作成

$ gpg --gen-key   
gpg (GnuPG) 2.0.28; Copyright (C) 2015 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
Your selection? 
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 
Requested keysize is 2048 bits
Please specify how long the key should be valid.
         0 = key does not expire
      <n>  = key expires in n days
      <n>w = key expires in n weeks
      <n>m = key expires in n months
      <n>y = key expires in n years
Key is valid for? (0) 
Key does not expire at all
Is this correct? (y/N) y

GnuPG needs to construct a user ID to identify your key.

Real name: kazue
Email address: xxx@xxx.jp
Comment: 
You selected this USER-ID:
    "kazue <xxx@xxx.jp>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O
You need a Passphrase to protect your secret key.

We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
gpg: key 3011578B marked as ultimately trusted
public and secret key created and signed.

gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
pub   2048R/3011578B 2021-01-28
      Key fingerprint = B8AB 7395 C85D C8D3 DFA7  8A1B 4C10 32A4 3011 578B
uid       [ultimate] kazue <xxx@xxx.jp>
sub   2048R/A6E23953 2021-01-28

圧縮ファイル作成

$ helm package wordpress --sign --keyring ~/.gnupg/secring.gpg --key 'kazue'     
Password for key "kazue <xxx@xxx.jp>" >  
Successfully packaged chart and saved it to: /home/ec2-user/environment/wordpress-9.0.3.tgz

検証

$ helm verify wordpress-9.0.3.tgz --keyring ~/.gnupg/pubring.gpg
Signed by: kazue <xxx@xxx.jp>
Using Key With Fingerprint: B8AB7395C85DC8D3DFA78A1B4C1032A43011578B
Chart Hash Verified: sha256:adc53579beb3cd51b93a33f1866c9a8cdad24900d94927c00693bf534e5295f3

version

print the client version information

どのコマンドにもある、バージョン確認のためのサブコマンドです。

$ helm version 
version.BuildInfo{Version:"v3.5.0", GitCommit:"32c22239423b3b4ba6706d450bd044baffdcf9e6", GitTreeState:"clean", GoVersion:"go1.15.6"}
$ helm version --short
v3.5.0+g32c2223