1. 概述

1. 引入helm

　　之前我们部署一个应用的基本过程： 部署deployment、service、ingress。如果少数应用还好，如果部署微服务项目，每个服务有一套yaml，需要维护大量的yaml， 可能管理不太方便。

　　helm可以把这些yaml 作为一个整体管理，实现yaml 高效复用，可以实现应用级别的管理。

2. 简介

　　helm 是k8s 的一个包管理工具，类似于linux 下面的包管理器，比如yum\apt 等，可以很方便的将之前打包好的yaml 文件部署到k8s 集群上。

三个重要概念：

(1) heml: 一个命令行客户端工具

(2) chart: 把yaml 打包，是yaml 集合

(3) Release: 基于chart 部署实体，应用级别的版本管理。

其架构如下：

2. 安装以及查看

1. 下载安装

到 https://github.com/helm/helm/tags 下载， 然后上传到linux

解压且将解压之后helm 目录复制到 /usr/bin 目录

[root@k8smaster1 helm]# tar -zxvf ./helm-v3.0.0-linux-amd64.tar.gz 
linux-amd64/
linux-amd64/helm
linux-amd64/README.md
linux-amd64/LICENSE
[root@k8smaster1 helm]# cp ./linux-amd64/helm /usr/bin/

查看版本

[root@k8smaster1 helm]# helm version
version.BuildInfo{Version:"v3.0.0", GitCommit:"e29ce2a54e96cd02ccfce88bee4f58bb6e2a28b6", GitTreeState:"clean", GoVersion:"go1.13.4"}

2. 配置仓库：

[root@k8smaster1 helm]# helm repo add stable http://mirror.azure.cn/kubernetes/charts
"stable" has been added to your repositories
[root@k8smaster1 helm]# helm repo list
NAME    URL                                     
stable  http://mirror.azure.cn/kubernetes/charts
[root@k8smaster1 helm]# helm repo remove stable
"stable" has been removed from your repositories
[root@k8smaster1 helm]# helm repo list
Error: no repositories to show
[root@k8smaster1 helm]# helm repo add stable http://mirror.azure.cn/kubernetes/charts
"stable" has been added to your repositories
Usage:  helm repo add [NAME] [URL] [flags]
[root@k8smaster1 helm]# helm repo update
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈ Happy Helming!⎈ 

 3. 简单使用

语法：

搜索： helm search repo 名称

安装: heml install 安装名称 搜索之后应用名称

查看安装状态: heml list \ helm status 安装名称

1. 测试：

[root@k8smaster1 helm]# helm search repo weave
NAME                    CHART VERSION   APP VERSION     DESCRIPTION                                       
stable/weave-cloud      0.3.9           1.4.0           DEPRECATED - Weave Cloud is a add-on to Kuberne...
stable/weave-scope      1.1.12          1.12.0          DEPRECATED - A Helm chart for the Weave Scope c...
[root@k8smaster1 helm]# helm install ui stable/weave-scope
NAME: ui
LAST DEPLOYED: Wed Jan 19 23:44:18 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
You should now be able to access the Scope frontend in your web browser, by
using kubectl port-forward:

kubectl -n default port-forward $(kubectl -n default get endpoints \
ui-weave-scope -o jsonpath='{.subsets[0].addresses[0].targetRef.name}') 8080:4040

then browsing to http://localhost:8080/.
For more details on using Weave Scope, see the Weave Scope documentation:

https://www.weave.works/docs/scope/latest/introducing/
[root@k8smaster1 helm]# helm list
NAME    NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
ui      default         1               2022-01-19 23:44:18.40844005 -0500 EST  deployed        weave-scope-1.1.12      1.12.0     
[root@k8smaster1 helm]# helm status ui
NAME: ui
LAST DEPLOYED: Wed Jan 19 23:44:18 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
You should now be able to access the Scope frontend in your web browser, by
using kubectl port-forward:

kubectl -n default port-forward $(kubectl -n default get endpoints \
ui-weave-scope -o jsonpath='{.subsets[0].addresses[0].targetRef.name}') 8080:4040

then browsing to http://localhost:8080/.
For more details on using Weave Scope, see the Weave Scope documentation:

https://www.weave.works/docs/scope/latest/introducing/

删除chart 用如下命令：

[root@k8smaster1 volumestest]# helm list
NAME    NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
ui      default         1               2022-01-19 23:44:18.40844005 -0500 EST  deployed        weave-scope-1.1.12      1.12.0     
web2    default         1               2022-01-21 01:30:45.768452911 -0500 EST deployed        mychart-0.1.0           1.16.0     
[root@k8smaster1 volumestest]# helm delete web2
release "web2" uninstalled
[root@k8smaster1 volumestest]# helm list
NAME    NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
ui      default         1               2022-01-19 23:44:18.40844005 -0500 EST  deployed        weave-scope-1.1.12      1.12.0

2. 修改service type 类型

(1) 查看类型，发现其 type 是 ClusterIP

[root@k8smaster1 ~]# kubectl get svc
NAME             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes       ClusterIP   10.96.0.1       <none>        443/TCP          11d
nginx            NodePort    10.109.175.64   <none>        80:32503/TCP     3d1h
tomcat           NodePort    10.100.178.25   <none>        8080:30158/TCP   3d
ui-weave-scope   ClusterIP   10.107.48.241   <none>        80/TCP           6h1m

 (2) 修改为NodePort

执行如下命令：

[root@k8smaster1 ~]# kubectl edit svc ui-weave-scope
service/ui-weave-scope edited
[root@k8smaster1 ~]# kubectl get svc
NAME             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes       ClusterIP   10.96.0.1       <none>        443/TCP          11d
nginx            NodePort    10.109.175.64   <none>        80:32503/TCP     3d2h
tomcat           NodePort    10.100.178.25   <none>        8080:30158/TCP   3d1h
ui-weave-scope   NodePort    10.107.48.241   <none>        80:30197/TCP     6h29m

 改为NodePort 即可从主机通过k8s的节点访问30197 端口查看相关界面

3. 查看:

weave scope  是一个k8s可视化界面，可以查看k8s 集群相关

 weave scope 可以查看好多信息，比如pods 信息，每个pod 的日志以及secribe信息，测试：

(1) 查看所有pods

 

(2) 查看pod 信息

 (3) 查看日志

 (4) 查看describe 信息

 (5) 查看service信息

(6) 查看pod 对应的容器信息以及进入容器

1》 点击containers 容器

 

 2》查看容器信息以及进入容器

 3. heml 创建chart

1. 创建mychart， 实际会 创建一个文件夹

[root@k8smaster1 chart]# helm create mychart
Creating mychart
[root@k8smaster1 chart]# ls
mychart
[root@k8smaster1 chart]# cd mychart/

查看相关目录信息：

[root@k8smaster1 mychart]# ll -R
.:
total 8
drwxr-xr-x 2 root root    6 Jan 20 23:12 charts
-rw-r--r-- 1 root root  905 Jan 20 23:12 Chart.yaml
drwxr-xr-x 3 root root  146 Jan 20 23:12 templates
-rw-r--r-- 1 root root 1490 Jan 20 23:12 values.yaml

./charts:
total 0

./templates:
total 24
-rw-r--r-- 1 root root 1626 Jan 20 23:12 deployment.yaml
-rw-r--r-- 1 root root 1847 Jan 20 23:12 _helpers.tpl
-rw-r--r-- 1 root root 1030 Jan 20 23:12 ingress.yaml
-rw-r--r-- 1 root root 1581 Jan 20 23:12 NOTES.txt
-rw-r--r-- 1 root root  207 Jan 20 23:12 serviceaccount.yaml
-rw-r--r-- 1 root root  361 Jan 20 23:12 service.yaml
drwxr-xr-x 2 root root   34 Jan 20 23:12 tests

./templates/tests:
total 4
-rw-r--r-- 1 root root 383 Jan 20 23:12 test-connection.yaml

Chart.yaml 当前chart的版本信息

charts: 一个空文件夹

templates: 一些默认的yaml 文件

values.yaml: 类似于全局变量提取的文件，抽取之后templates 文件夹下面的yaml 可以复用该变量

2. 创建deployment 和 service 的yaml

[root@k8smaster1 templates]# kubectl create deployment web1 --image=nginx --dry-run -o yaml > deployment.yaml
W0120 23:20:39.498957  118143 helpers.go:535] --dry-run is deprecated and can be replaced with --dry-run=client.
[root@k8smaster1 templates]# ls
deployment.yaml
[root@k8smaster1 templates]# kubectl apply -f deployment.yaml 
deployment.apps/web1 created
[root@k8smaster1 templates]# kubectl expose deployment web1 --port=80 --target-port=80 --type=NodePort --dry-run -o yaml > service.yaml
W0120 23:23:08.805846  118735 helpers.go:535] --dry-run is deprecated and can be replaced with --dry-run=client.
[root@k8smaster1 templates]# kubectl delete -f deployment.yaml 
deployment.apps "web1" deleted
[root@k8smaster1 templates]# ls
deployment.yaml  service.yaml

　　先创建deployment.yaml, 然后创建资源； 然后生成service.yaml, 这个要求暴露的deployment 必须存在。然后删掉之前创建的的deployment。 这么操作是为了得到两个yaml。

3. 执行创建

[root@k8smaster1 chart]# helm install web1 mychart/
NAME: web1
LAST DEPLOYED: Thu Jan 20 23:26:09 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
[root@k8smaster1 chart]# kubectl get pods,svc -o wide | grep web1
pod/web1-7f87dfbd56-9c6rb                           1/1     Running   0          19s     10.244.2.105     k8snode2     <none>           <none>
service/web1             NodePort    10.111.151.4    <none>        80:30539/TCP     19s     app=web1

4. 执行升级

1. 编辑yaml 文件， 将nginx 的image 版本改为1.14

2. 执行如下命令升级

[root@k8smaster1 chart]# helm upgrade web1 mychart
Release "web1" has been upgraded. Happy Helming!
NAME: web1
LAST DEPLOYED: Thu Jan 20 23:36:36 2022
NAMESPACE: default
STATUS: deployed
REVISION: 2
TEST SUITE: None

3. weave-scope 查看nginx 版本

 或者自己进入容器查看：

[root@k8smaster1 chart]# kubectl exec -it web1-6cffb575cb-wbfrf -- bash
root@web1-6cffb575cb-wbfrf:/# nginx -v
nginx version: nginx/1.14.2

5. 使用values.yaml 实现变量提取

1. values.yaml 增加如下配置

replicaCount: 1
image: nginx:1.15
label: nginx
port: 80

2. templates的yaml 文件使用values.yaml 定义的变量

(1) 通过表达式形式获取

{{ .Values.varname}}

(2) 获取全局信息

{{ .Release.Name}} 获取发布名称

3. 修改templates下面的两个yaml

(1) deployment.yaml 文件如下

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: {{ .Values.label}}
  name: {{ .Release.Name}}-deploy
spec:
  replicas: {{ .Values.replicaCount}}
  selector:
    matchLabels:
      app: {{ .Values.label}}
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: {{ .Values.label}}
    spec:
      containers:
      - image: {{ .Values.image}}
        name: nginx
        resources: {}
status: {}

(2) service.yaml 内容如下：

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: {{ .Values.label}}
  name: {{ .Release.Name}}-svc
spec:
  ports:
  - port: {{ .Values.port}}
    protocol: TCP
    targetPort: {{ .Values.port}}
  selector:
    app: {{ .Values.label}}
  type: NodePort
status:
  loadBalancer: {}

4. 测试执行查看输出的yaml

[root@k8smaster1 chart]# helm install --dry-run web2 mychart/
NAME: web2
LAST DEPLOYED: Fri Jan 21 01:28:30 2022
NAMESPACE: default
STATUS: pending-install
REVISION: 1
TEST SUITE: None
HOOKS:
MANIFEST:
---
# Source: mychart/templates/service.yaml
apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: nginx
  name: web2-svc
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: NodePort
status:
  loadBalancer: {}
---
# Source: mychart/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: nginx
  name: web2-deploy
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.15
        name: nginx
        resources: {}
status: {}

5. 执行创建查看资源

[root@k8smaster1 chart]# helm install web2 mychart/
NAME: web2
LAST DEPLOYED: Fri Jan 21 01:30:45 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
[root@k8smaster1 chart]# kubectl get pods,svc -o wide | grep web2
pod/web2-deploy-7d79cb6c68-7sjkb                    1/1     Running   0          52s     10.244.2.106     k8snode2     <none>           <none>
service/web2-svc         NodePort    10.96.166.138   <none>        80:32181/TCP     52s     app=nginx

weave-scope 查看镜像信息：