Helm示例

Helm 示例

此示例将使用裸机上的 ingress 并采用 Nginx Ingress 控制器和 metalLB。

在我的 helm-demo 文件夹中，我有 templates 目录以及 Chart 和 values YAML 文件：

k8s-master@master:~/helm-demo$ ls
Chart.yaml  templates  values.yaml
​

在 Chart.yaml 文件内：

name: my-first-demo
version: 1.0.0
description: easy helm demo
maintainers:
- name: Siwar
​

这是用于描述每个部署的元数据。

现在进入 templates 目录：

k8s-master@master:~/helm-demo/templates$ ls
deployment.yaml  ingress.yaml  service.yaml
​

deployment.yaml 文件包含一个简单的 nginx 部署：

apiVersion: apps/v1
kind: Deployment
metadata: 
  name: my-nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 3
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80

​

而 service.yaml 文件：

apiVersion: v1
kind: Service
metadata: 
  name: my-nginx-service
spec:
  selector:
    app: nginx
  ports:
  - name: main
    protocol: TCP
    port: 80
​

以及 ingress.yaml 文件：

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-nginx-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    http.port: "443"
spec:
  ingressClassName: nginx
  rules:
  - http:
      paths:
      - path: /testpath
        pathType: Prefix
        backend:
          service:
            name: my-nginx-service
            port:
              number: 80

​

我们正在 ingress 上暴露端口 443。

接下来是 helm install：

k8s-master@master:~$ helm install --generate-name helm-demo/
NAME: helm-demo-1660310990
LAST DEPLOYED: Fri Aug 12 06:29:50 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
​

因此，借助 Helm 和仅需一个命令行工具 helm install，我们可以非常轻松且快速地部署我们的应用程序。

k8s-master@master:~$ kubectl get all
NAME                                      READY   STATUS              RESTARTS   AGE
pod/my-nginx-deployment-9456bbbf9-c74rs   0/1     ContainerCreating   0          11s
pod/my-nginx-deployment-9456bbbf9-k4cdb   0/1     ContainerCreating   0          11s
pod/my-nginx-deployment-9456bbbf9-mm7dm   0/1     ContainerCreating   0          11s

NAME                       TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
service/kubernetes         ClusterIP   10.96.0.1        <none>        443/TCP   22m
service/my-nginx-service   ClusterIP   10.100.146.193   <none>        80/TCP    11s

NAME                                  READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/my-nginx-deployment   0/3     3            0           11s

NAME                                            DESIRED   CURRENT   READY   AGE
replicaset.apps/my-nginx-deployment-9456bbbf9   3         3         0       11s
​

我们可以通过 ingress IP 192.168.1.240 and specifying the path /testpath:

The usual way to do this with kubectl is by executing the kubectl apply 命令行工具来检查我们的应用程序是否在浏览器中运行。

Helm 的另一个重要功能是占位符！
因此，如果我们查看另一个 deployment.yaml 文件：

apiVersion: apps/v1
kind: Deployment
metadata: 
  name: my-nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: {{.Values.scale}}
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80
​

{{.Values.scale}}placeholder makes it possible to modify the configuration without having to edit the actual manifest file every time.

So whatever the value of scale is in values.yaml file is going to be the value of the configuration file.

The values.yaml 文件：

k8s-master@master:~/helming-once-more$ cat values.yaml
scale: 3
​

现在让我们再次安装我们的应用程序：

k8s-master@master:~$ helm install another-demo helming-once-more/
NAME: another-demo
LAST DEPLOYED: Fri Aug 12 11:48:53 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
​

只是为了检查我们的 Pod 是否已启动并运行：

k8s-master@master:~$ kubectl get pods
NAME                                  READY   STATUS    RESTARTS   AGE
my-nginx-deployment-9456bbbf9-mx45n   1/1     Running   0          3m9s
my-nginx-deployment-9456bbbf9-rqkmw   1/1     Running   0          3m9s
my-nginx-deployment-9456bbbf9-tl4wj   1/1     Running   0          3m9s
​

因此，由于在 values.yaml 文件中的 scale 值，我们现在有 3 个 Pod。

出于某种原因，我们需要扩展我们的 Pod 数量：

k8s-master@master:~$ helm upgrade --set scale=5 another-demo ./helming-once-more/
Release "another-demo" has been upgraded. Happy Helming!
NAME: another-demo
LAST DEPLOYED: Fri Aug 12 11:55:14 2022
NAMESPACE: default
STATUS: deployed
REVISION: 2
TEST SUITE: None
​

k8s-master@master:~$ kubectl get pod
NAME                                  READY   STATUS    RESTARTS   AGE
my-nginx-deployment-9456bbbf9-7ddlm   1/1     Running   0          95s
my-nginx-deployment-9456bbbf9-mx45n   1/1     Running   0          8m9s
my-nginx-deployment-9456bbbf9-rqkmw   1/1     Running   0          8m9s
my-nginx-deployment-9456bbbf9-tl4wj   1/1     Running   0          8m9s
my-nginx-deployment-9456bbbf9-tpsqv   1/1     Running   0          96s
​

最后，我们将删除我们的应用程序：

k8s-master@master:~$ helm list
NAME           NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
another-demo    default         2               2022-08-12 11:55:14.913503686 -0700 PDT deployed        another-demo-1.0.0
k8s-master@master:~$ helm uninstall another-demo
release "another-demo" uninstalled
​

声明:
本文件灏天文库团队进行了翻译。尽管我们力求准确，但请注意，翻译可能包含错误或不准确之处。原文档以其原始语言为准。我们不对因使用此翻译而产生的任何误解或误译负责。