Helm Chart部署最简SpringBoot到K8S（AWS EKS版）

目标

这里假设，我们已经基本会使用k8s的kubectl命令进行部署了，也已经会自己打docker镜像推送到AWS ECR上面去了。而且，已经在云上准备好了AWS ECR镜像库和AWS EKS的k8s集群了。
这个前提上面，我们今天使用Helm Chart项目准备k8s的yaml配置文件来部署一个最简单的Springboot项目到AWS的k8s集群。

Helm项目结构

.
└── my-kubernetes-app
    ├── configmaps
    ├── crons
    ├── deployments
    ├── hpas
    ├── pdbs
    ├── podpriorities
    ├── pvcs
    ├── services
    ├── statefulsets
    └── ...

上面这个是网上一位工友总结出来的Helm Chart目录结构。在这之前，还是先了解了解Helm是干什么的吧？Helm自身定位是给k8s的包管理器，但是，他的Helm Chart项目被我们现在这里用于管理生成k8s配置模板，来生成不同环境的k8s yaml配置文件。简单来说，Helm Chart就是一个根据模板生成配置文件的工具。
下面是我这次用的Helm目录结构：

./
├── Chart.yaml
├── templates
│   ├── configmaps
│   │   ├── demo.yaml
│   │   └── demo2.yaml
│   ├── ingress.yaml
│   ├── secrets
│   │   └── mysql.yaml
│   └── services
│       ├── demo.yaml
│       └── demo2.yaml
├── values-prod.yaml
├── values-uat.yaml
└── values.yaml

这里只有简单的secrets和services的简单文件夹划分。我这里只做java层面的拆分，数据库共用一个，嗯，我这里是属于伪微服务了。如果要进一步拆分的话，就像上面那位道友那样，把deployments从services里面统统拆出来。我这里是最简形态，比较原始的项目状态，后期，可以在这个基础上面加hpa。算了，精力有限，就先演化到这样吧！
这里我是先使用helm create命令，创建出一个超简单的helm项目的，具体命令如下：

helm create mychart

然后，在这个基础上面逐渐演化到上面那个secrets和services，ingress样子。

Chart.yaml

apiVersion: v2
name: my-demo
description: my-demo

# A chart can be either an 'application' or a 'library' chart.
#
# Application charts are a collection of templates that can be packaged into versioned archives
# to be deployed.
#
# Library charts provide useful utilities or functions for the chart developer. They're included as
# a dependency of application charts to inject those utilities and functions into the rendering
# pipeline. Library charts do not define any templates and therefore cannot be deployed.
type: application

# This is the chart version. This version number should be incremented each time you make changes
# to the chart and its templates, including the app version.
# Versions are expected to follow Semantic Versioning (https://semver.org/)
version: 0.1.0

# This is the version number of the application being deployed. This version number should be
# incremented each time you make changes to the application. Versions are not expected to
# follow Semantic Versioning. They should reflect the version the application is using.
# It is recommended to use it with quotes.
appVersion: "1.16.0"

这里是Helm Chart基本信息。

values.yaml

ingress:
  security:
    groups: cloudfront-only
services:
  demo:
    name: demo
    port: 8080
    path: /api/demo
    health:
      path: /actuator/health
      port: 8081
  demo2:
    name: demo2
    port: 8080
    path: /api/demo2
    health:
      path: /actuator/health
      port: 8081

这里设置了ingress的安全组，这个cloudfront-only安全组，主要设置alb主要接收来自cloudfront的流量。这里业务服务的名称，端口，前缀路径，以及健康检查的路径和端口。

values-uat.yaml

replicas: 1
spring:
  profiles:
    active: uat
mysql:
  config:
    name: mysql
  HOST: xxxx-uat.xxxxx.us-east-1.rds.amazonaws.com
  DB_USERNAME: bXl1c2VybmFtZQ==
  DB_PASSWORD: bXlwYXNzd29yZA==
docker:
  services:
    demo:
      images: xxxxxxx.dkr.ecr.us-east-1.amazonaws.com/demo:latest
      name: demo
    demo2:
      images: xxxxxxx.dkr.ecr.us-east-1.amazonaws.com/demo2:latest
      name: demo2

这里主要是针对uat环境的设置，主要就是副本数，spring，mysql和docker镜像的配置。

templates/ingress.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: {{ .Chart.Name }}-ingress
  namespace: {{ .Release.Namespace }}
  annotations:
    alb.ingress.kubernetes.io/load-balancer-name: {{ .Chart.Name }}-ingress
    alb.ingress.kubernetes.io/security-groups: {{ .Values.ingress.security.groups }}
    alb.ingress.kubernetes.io/manage-backend-security-group-rules: "true"
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/target-type: ip
spec:
  ingressClassName: alb
  rules:
  - http:
      paths:
      - backend:
          service:
            name: {{ .Values.services.demo.name }}
            port:
              number: {{ .Values.services.demo.port }}
        path: {{ .Values.services.demo.path }}
        pathType: Prefix

这里主要就是k8s的ingress配置，主要就是alb配置和具体服务的网关配置。

templates/secrets/mysql.yaml

apiVersion: v1
data:
  DB_USERNAME: {{ .Values.mysql.DB_USERNAME }}
  DB_PASSWORD: {{ .Values.mysql.DB_PASSWORD }}
kind: Secret
metadata:
  name: {{ .Values.mysql.config.name }}-secret
  namespace: {{ .Release.Namespace }}

这里是mysql的secrets配置。

templates/services/demo.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: {{ .Values.services.demo.name }}
  name: {{ .Values.services.demo.name }}
  namespace: {{ .Release.Namespace }}
spec:
  replicas: {{ .Values.replicas }}
  selector:
    matchLabels:
      app: {{ .Values.services.demo.name }}
  template:
    metadata:
      labels:
        app: {{ .Values.services.demo.name }}
    spec:
      containers:
        - image: {{ .Values.docker.services.demo.images }}
          name: {{ .Values.docker.services.demo.name }}
          envFrom:
            - secretRef:
                name: {{ .Values.mysql.config.name }}-secret
            - configMapRef:
                name: {{ .Values.services.demo.name }}-configmap
#          resources:
#            requests:
#              memory: "2Gi"
#              cpu: "2"
#            limits:
#              memory: "2Gi"
#              cpu: "2"
          # 准备检查，通过则接入流量
          readinessProbe:
            httpGet:
              path: {{ .Values.services.demo.health.path }}
              port: {{ .Values.services.demo.health.port }}
          # 活力检查，不通过时重启容器
          livenessProbe:
            httpGet:
              path: {{ .Values.services.demo.health.path }}
              port: {{ .Values.services.demo.health.port }}
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: demo
  name: {{ .Values.services.demo.name }}
  namespace: {{ .Release.Namespace }}
  annotations:
    alb.ingress.kubernetes.io/healthcheck-path: {{ .Values.services.demo.health.path }}
    alb.ingress.kubernetes.io/healthcheck-port: '{{ .Values.services.demo.health.port }}'
spec:
  ports:
    - name: http
      port: {{ .Values.services.demo.port }}
      targetPort: {{ .Values.services.demo.port }}
  selector:
    app: {{ .Values.services.demo.name }}
  type: ClusterIP

这里主要配置了demo服务的Deployment和Service配置。

templates/services/demo2.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: {{ .Values.services.demo2.name }}
  name: {{ .Values.services.demo2.name }}
  namespace: {{ .Release.Namespace }}
spec:
  replicas: {{ .Values.replicas }}
  selector:
    matchLabels:
      app: {{ .Values.services.demo2.name }}
  template:
    metadata:
      labels:
        app: {{ .Values.services.demo2.name }}
    spec:
      containers:
        - image: {{ .Values.docker.services.demo2.images }}
          name: {{ .Values.docker.services.demo2.name }}
          envFrom:
            - secretRef:
                name: {{ .Values.mysql.config.name }}-secret
            - configMapRef:
                name: {{ .Values.services.demo2.name }}-configmap
#          resources:
#            requests:
#              memory: "2Gi"
#              cpu: "2"
#            limits:
#              memory: "2Gi"
#              cpu: "2"
          # 准备检查，通过则接入流量
          readinessProbe:
            httpGet:
              path: {{ .Values.services.demo2.health.path }}
              port: {{ .Values.services.demo2.health.port }}
          # 活力检查，不通过时重启容器
          livenessProbe:
            httpGet:
              path: {{ .Values.services.demo2.health.path }}
              port: {{ .Values.services.demo2.health.port }}
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: {{ .Values.services.demo2.name }}
  name: {{ .Values.services.demo2.name }}
  namespace: {{ .Release.Namespace }}
  annotations:
    alb.ingress.kubernetes.io/healthcheck-path: {{ .Values.services.demo2.health.path }}
    alb.ingress.kubernetes.io/healthcheck-port: '{{ .Values.services.demo2.health.port }}'
spec:
  ports:
    - name: http
      port: {{ .Values.services.demo2.port }}
      targetPort: {{ .Values.services.demo2.port }}
  selector:
    app: {{ .Values.services.demo2.name }}
  type: ClusterIP

configmaps/demo.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Values.services.demo.name }}-configmap
  namespace: {{ .Release.Namespace }}
data:
  SPRING_PROFILES_ACTIVE: {{ .Values.spring.profiles.active }}
  MYSQL_HOST: {{ .Values.mysql.HOST }}

configmaps/demo2.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Values.services.demo2.name }}-configmap
  namespace: {{ .Release.Namespace }}
data:
  SPRING_PROFILES_ACTIVE: {{ .Values.spring.profiles.active }}
  MYSQL_HOST: {{ .Values.mysql.HOST }}

Helm部署

 helm install -f ./values-uat.yaml my-demo ./ -n my-demo --create-namespace

输出例子：

NAME: my-demo
LAST DEPLOYED: Thu Mar 14 15:19:53 2024
NAMESPACE: my-demo
STATUS: deployed
REVISION: 1
TEST SUITE: None

Helm检查部署

helm ls -n my-demo

结果如下：

NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART           APP VERSION
my-demo          my-demo         1               2024-03-14 15:19:53.658731 +0800 CST    deployed        my-demo-0.1.0 1.16.0

kubectl检查

# 检查ingress网关
kubectl get ingress -n my-demo
# 检查svc
kubectl get svc -n my-demo
# 检查deploy
kubectl get deploy -n my-demo
# 检查pods
kubectl get pods -n my-demo