使用helm部署nginx

初次使用helm，根据网上的一些教程，记录一些自己的理解。

• helm的安装
  安装过程非常简单，根据以下操作即可。

wget https://get.helm.sh/helm-v3.4.1-linux-amd64.tar.gz
cd /opt/helm/
tar -xf helm-v3.4.1-linux-amd64.tar.gz
cp helm /usr/local/bin
chmod a+x /usr/local/bin/helm

（包下不来的同学可以重复执行wget，多几次就能下下来。）

• 尝试部署nginx应用

建立一个目录，目录内容结构如下：

[root@kube-master-3 nginx-hw]# tree .
.
├── Chart.yaml
├── templates
│   ├── deployment.yaml
│   └── service.yaml
└── values.yaml

• 文件讲解

[root@kube-master-3 nginx-hw]# cat Chart.yaml
apiVersion: v1
appVersion: v2.2
description: first helm
keywords:
- hw-nginx
name: nginx-hw
version: v1.0.0
（此文件是release的一些信息）

[root@kube-master-3 nginx-hw]# cat values.yaml
deployname: hw-nginx
replicaCount: 2
images:
  repository: reg.harbor.com/harbor-test/nginx-node3  #这是从我自己的harbor拉取镜像
  tag: v1
（此文件可以说是定义的了一些变量，可以在后面的文件进行引用）

[root@kube-master-3 nginx-hw]# cat templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Values.deployname }}
  labels:
    app: hw-nginx
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: hw-nginx
  template:
    metadata:
      labels:
        app: hw-nginx
    spec:
      containers:
      - name: hw-nginx
        image: {{ .Values.images.repository }}
        imagePullPolicy: IfNotPresent
        ports:
          - containerPort: 80
（此文件中使用到的变量就是values.yaml定义的变量）

[root@kube-master-3 nginx-hw]# cat templates/service.yaml
apiVersion: v1
kind: Service
metadata:
  name: hw-nginx
  namespace: default
spec:
  type: NodePort
  selector:
    app: hw-nginx
  ports:
 - name: http
    port: 80
    targetPort: 80
    nodePort: 30001
    protocol: TCP
（建立一个svc，跟写k8s的yaml文件是一样的）

• 使用helm创建nginx服务

试运行
   helm install --dry-run --debug hw-nginx-f .
  【hw-nginx-f是release名字，.表示当前目录】
运行效果
[root@kube-master-3 nginx-hw]# helm install --dry-run --debug hw-nginx-f .
install.go:172: [debug] Original chart version: ""
install.go:189: [debug] CHART PATH: /opt/helm-charts/nginx-hw

NAME: hw-nginx-f
LAST DEPLOYED: Mon Mar 15 15:58:15 2021
NAMESPACE: default
STATUS: pending-install
REVISION: 1
TEST SUITE: None
USER-SUPPLIED VALUES:
{}

COMPUTED VALUES:
deployname: hw-nginx
images:
  repository: reg.harbor.com/harbor-test/nginx-node3  #这是我自己搭建的harbor
  tag: latest
replicaCoutn: 2

HOOKS:
MANIFEST:
---
# Source: nginx-hw/templates/service.yaml
apiVersion: v1
kind: Service
metadata:
  name: hw-nginx
  namespace: default
spec:
  type: NodePort
  selector:
    app: hw-nginx
  ports:
  - name: http
    port: 80
    targetPort: 80
    nodePoer: 30001
    protocol: TCP
---
# Source: nginx-hw/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hw-nginx
  labels:
    app: hw-nginx
spec:
  replicas:
  selector:
    matchLabels:
      app: hw-nginx
  template:
    metadata:
      labels:
        app: hw-nginx
    spec:
      containers:
      - name: hw-nginx
        image: reg.harbor.com/harbor-text/nginx-node3:latest
        imagePullPolicy: IfNotPresent
        ports:
          - containerPort: 80
（试运行会列出所有相关的文件）

部署并查看
[root@kube-master-3 nginx-hw]# helm install  hw-nginx-f .
NAME: hw-nginx-f
LAST DEPLOYED: Mon Mar 15 15:58:55 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
[root@kube-master-3 nginx-hw]# helm list
NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART           APP VERSION
hw-nginx-f      default         1               2021-03-15 15:58:55.298302751 +0800 CST deployed        nginx-hw-v1.0.0 v2.2

[root@kube-master-3 nginx-hw]# kubectl get po
NAME                        READY   STATUS    RESTARTS   AGE
hw-nginx-85c74459b6-lkbmc   1/1     Running   0          65m
hw-nginx-85c74459b6-zhq9b   1/1     Running   0          65m

如果需要改变部署的文件，改变之后，可以用以下命令进行更新

helm upgrade hw-nginx-f .

部署完毕之后就可以根据svc提供的端口进行访问

[root@kube-master-3 nginx-hw]# kubectl get svc
NAME                TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
hw-nginx            NodePort    10.100.26.124   <none>        80:30001/TCP   123m

[root@kube-master-3 nginx-hw]# curl 192.168.186.13:30001 -I
HTTP/1.1 200 OK
Server: nginx/1.19.6
Date: Mon, 15 Mar 2021 10:02:43 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 15 Dec 2020 13:59:38 GMT
Connection: keep-alive
ETag: "5fd8c14a-264"
Accept-Ranges: bytes

初次体验helm完毕。