使用helm管理复杂kubernetes应用

1. 查看仓库：

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

启动本地仓库：

$ helm serve&
[1] 15148
Regenerating index. This may take a moment.
Now serving you on 127.0.0.1:8879

2. 创建helm应用

helm create test-chart

结构如下：

├─test-chart
├── charts
├── Chart.yaml
├── templates
│   ├── deployment.yaml
│   ├── _helpers.tpl
│   ├── NOTES.txt
│   └── service.yaml
└── values.yaml

简单更改 values.yaml 配置如下

replicaCount: 1

image:
  repository: daemonza/test
  tag: latest
  pullPolicy: IfNotPresent


service:
  name: test
  type: ClusterIP
  internalport: 80
  externalPort: 80

resources:
  limits:
    cpu: 100m
    memory: 128Mi
  requests:
    cpu: 100m
    memory: 128Mi

更改Chart.yaml 配置如下

apiVersion: v1
appVersion: "1.0"
description: A Helm chart for Kubernetes
name: test-chart
version: 0.1.0

3. 将test-chart打包

$ helm package test-chart
Successfully packaged chart and saved it to: D:zhuojian-projects
ubik-Thealth-doc详细设计helm	est-chart-0.1.0.tgz

打包的同时，会拷贝一份生成的 tgz 文件到本地仓库。

4. 如法炮制2个 chart 包：test-chart2， test-chart3，且进行打包。

$ helm search test
NAME                    CHART VERSION   APP VERSION     DESCRIPTION
local/test-chart        0.2.0           1.0             A Helm chart for Kubernetes
local/test-chart2       0.1.0           1.0             A Helm chart for Kubernetes
local/test-chart3       0.2.0           4.0             A Helm chart for Kubernetes

5. 假设test-chart依赖：0.1.0版本的test-chart2， 0.2.0版本的test-chart3，针对包依赖关系的描述，可以使用文件 requirements.yaml，内容如下：

dependencies:
- name: test-chart2
  version: "0.1.0"
  repository: http://127.0.0.1:8879
- name: test-chart3
  version: "0.2.0"
  repository: http://127.0.0.1:8879

chart 目录如下

├─test-chart
├── charts
├── Chart.yaml
├── templates
│   ├── deployment.yaml
│   ├── _helpers.tpl
│   ├── NOTES.txt
│   ├── requirements.yaml
│   └── service.yaml
└── values.yaml

然后执行以下命令，将对应的依赖包下载到test-chart的charts目录下：

$ helm dep update test-chart
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "local" chart repository
...Successfully got an update from the "stable" chart repository
...Successfully got an update from the "incubator" chart repository
Update Complete.
Saving 2 charts
Downloading test-chart2 from repo http://127.0.0.1:8879
Downloading test-chart3 from repo http://127.0.0.1:8879
Deleting outdated charts

执行完之后，再次查看test-chart目录结构，会发现依赖包已经下载下来了：

├─test-chart
├── charts
│   ├── test-chart2-0.1.0.tgz
│   ├── test-chart3-0.2.0.tgz
├── Chart.yaml
├── templates
│   ├── deployment.yaml
│   ├── _helpers.tpl
│   ├── NOTES.txt
│   ├── requirements.yaml
│   └── service.yaml
└── values.yaml

将 test-chart2-0.1.0.tgz 解压缩，会发现也是一个完整的 test-chart2 的实例。

然后可以使用 helm 将 test-chart 安装部署，至此，就完成了 helm 对具有复杂依赖关系的 kubernetes 应用的管理。