Kubernetes(K8S) helm chart

阿新 • • 發佈：2022-12-05

感覺和放到一個 yaml 檔案中，用 ---- 分隔，操作繁瑣程度上，沒有太大區別

建立自定義 Chart

# 建立自定義的 chart 名為 mychart
[root@k8smaster ~]# helm create mychart
Creating mychart
[root@k8smaster ~]# cd mychart/
[root@k8smaster mychart]# ls
charts  
Chart.yaml  # 當前chart 屬性配置資訊
templates   # 編寫 yaml 檔案放到這個目錄，是 yaml 的集合
values.yaml # yaml檔案可以使用的全域性變數
[root@k8smaster mychart]#

建立 yaml 檔案

在 templates 資料夾中建立兩個 yaml 檔案

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: web1
  name: web1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: web1
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: web1
    spec:
      containers:
      - image: nginx
        name: nginx
        resources: {}
status: {}

service.yaml

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: web1
  name: web1
spec:
  ports:   
  - port: 80
    protocol: TCP
    targetPort: 80
    nodePort: 30390  # 可以指定暴露出去的埠，防止重啟 Pod 後發生變化 
  selector:
    app: web1
  type: NodePort
status:
  loadBalancer: {}

# 切換到 templates 目錄下
[root@k8smaster mychart]# cd templates/
# 建立一個web1應用--內容見上文
[root@k8smaster templates]# vi deployment.yaml
# 暴露埠--內容見上文
[root@k8smaster templates]# vi service.yaml
[root@k8smaster templates]#

安裝

[root@k8smaster ~]# helm install web1 mychart/
NAME: web1
LAST DEPLOYED: Mon Nov 28 14:26:34 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
1. Get the application URL by running these commands:
  export POD_NAME=$(kubectl get pods --namespace default -l "app.kubernetes.io/name=mychart,app.kubernetes.io/instance=web1" -o jsonpath="{.items[0].metadata.name}")
  echo "Visit http://127.0.0.1:8080 to use your application"
  kubectl --namespace default port-forward $POD_NAME 8080:80
[root@k8smaster ~]# helm list
NAME    NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
ui      default         1               2022-11-28 13:15:05.404335352 +0800 CST deployed        weave-scope-1.1.12      1.12.0     
web1    default         1               2022-11-28 14:26:34.854631893 +0800 CST deployed        mychart-0.1.0           1.16.0     
[root@k8smaster ~]# kubectl get pod,svc
NAME                                                READY   STATUS    RESTARTS   AGE
pod/nginx-f89759699-652r4                           1/1     Running   0          5d
pod/nginx-nfs-788564fbc8-g58xd                      1/1     Running   0          5d
pod/weave-scope-agent-ui-7qqd4                      1/1     Running   0          73m
pod/weave-scope-agent-ui-knqwk                      1/1     Running   0          73m
pod/weave-scope-agent-ui-r74cm                      1/1     Running   0          73m
pod/weave-scope-agent-ui-xnrht                      1/1     Running   0          73m
pod/weave-scope-cluster-agent-ui-7498b8d4f4-pmkzh   1/1     Running   0          73m
pod/weave-scope-frontend-ui-649c7dcd5d-jfg72        1/1     Running   0          73m
pod/web1-7f87dfbd56-w7p4d                           1/1     Running   0          91s

NAME                     TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
service/javademo1        NodePort    10.106.43.46     <none>        8111:31452/TCP   40d
service/kubernetes       ClusterIP   10.96.0.1        <none>        443/TCP          45d
service/nginx            NodePort    10.103.87.81     <none>        80:30339/TCP     45d
service/nginx-nfs        NodePort    10.99.84.9       <none>        80:30205/TCP     19d
service/ui-weave-scope   NodePort    10.101.4.212     <none>        80:30690/TCP     73m
service/web1             NodePort    10.100.238.141   <none>        80:30390/TCP     91s
[root@k8smaster ~]#

升級

[root@k8smaster ~]# helm upgrade web1 mychart/
Release "web1" has been upgraded. Happy Helming!
NAME: web1
LAST DEPLOYED: Mon Nov 28 14:29:39 2022
NAMESPACE: default
STATUS: deployed
REVISION: 2
NOTES:
1. Get the application URL by running these commands:
  export POD_NAME=$(kubectl get pods --namespace default -l "app.kubernetes.io/name=mychart,app.kubernetes.io/instance=web1" -o jsonpath="{.items[0].metadata.name}")
  echo "Visit http://127.0.0.1:8080 to use your application"
  kubectl --namespace default port-forward $POD_NAME 8080:80
[root@k8smaster ~]#

yaml 高效複用

通過傳遞引數，動態渲染模板 yaml 內容，動態傳入引數生成
在 chart values.yaml 檔案，定義 yaml 檔案全域性變數
在 values.yaml 定義變數和值
在具體 yaml檔案中，獲取定義變數的值

image、tag、label、port、replicas

定義變數

[root@k8smaster ~]# cd mychart/
[root@k8smaster mychart]# vi values.yaml
image: nginx
replicas: 1
tag: 1.16
label: nginx
port: 80

使用變數

方便統一定義
{{ .Values.變數名稱}}
{{ .Release.Name}} -> 獲取版本名稱

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Release.Name}}-deploy
spec:
  replicas: 1
  selector:
    matchLabels:
      app: {{ .Values.label}}
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: {{ .Values.label}}
    spec:
      containers:
      - image: {{ .Values.image}}
        name: nginx
        resources: {}
status: {}

service.yaml

apiVersion: v1
kind: Service
metadata: 
  name: {{ .Release.Name}}-deploy
spec:
  ports:
  - port: {{ .Values.port}}
    protocol: TCP
    targetPort: 80    
  selector:
    app: {{ .Values.label}}
  type: NodePort
status:
  loadBalancer: {}

[root@k8smaster mychart]# vi templates/deployment.yaml 
[root@k8smaster mychart]# vi templates/deployment.yaml 
[root@k8smaster mychart]# cd
[root@k8smaster ~]# helm install --dry-run web2 mychart/
# Source: mychart/templates/service.yaml
apiVersion: v1
kind: Service
metadata: 
  name: web2-deploy
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:
  name: web2-deploy
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx
        resources: {}
status: {}
[root@k8smaster ~]# helm install web2 mychart/
NAME: web2
LAST DEPLOYED: Mon Nov 28 15:13:48 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
[root@k8smaster ~]# kubectl get pod,svc 
NAME                                                READY   STATUS    RESTARTS   AGE
pod/nginx-f89759699-652r4                           1/1     Running   0          5d1h
pod/nginx-nfs-788564fbc8-g58xd                      1/1     Running   0          5d1h
pod/weave-scope-agent-ui-7qqd4                      1/1     Running   0          119m
pod/weave-scope-agent-ui-knqwk                      1/1     Running   0          119m
pod/weave-scope-agent-ui-r74cm                      1/1     Running   0          119m
pod/weave-scope-agent-ui-xnrht                      1/1     Running   0          119m
pod/weave-scope-cluster-agent-ui-7498b8d4f4-pmkzh   1/1     Running   0          119m
pod/weave-scope-frontend-ui-649c7dcd5d-jfg72        1/1     Running   0          119m
pod/web1-7f87dfbd56-w7p4d                           1/1     Running   0          47m
pod/web2-deploy-f89759699-9z5n4                     1/1     Running   0          22s

NAME                     TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
service/javademo1        NodePort    10.106.43.46     <none>        8111:31452/TCP   40d
service/kubernetes       ClusterIP   10.96.0.1        <none>        443/TCP          45d
service/nginx            NodePort    10.103.87.81     <none>        80:30339/TCP     45d
service/nginx-nfs        NodePort    10.99.84.9       <none>        80:30205/TCP     19d
service/ui-weave-scope   NodePort    10.101.4.212     <none>        80:30690/TCP     119m
service/web1             NodePort    10.100.238.141   <none>        80:30390/TCP     47m
service/web2-deploy      NodePort    10.111.219.124   <none>        80:30277/TCP     22s
[root@k8smaster ~]# helm uninstall web2
release "web2" uninstalled