使用Jenkins和单个模板部署多个Kubernetes组件

前言

在持续集成和部署中,我们通常需要部署多个实例或组件到Kubernetes集群中。通过Jenkins的管道脚本,我们可以自动化这个过程。在本文中,我将演示如何使用Jenkins Pipeline及单个YAML模板文件(.tpl)来部署多个类似的Kubernetes组件,而不需要为每个组件提供单独的模板文件。

问题背景

Jenkins Pipeline 脚本优化实践:从繁琐到简洁 批量生成 Kubernetes 部署模板:从 1 到20顺序模板

pipeline {    agent none // Use none at the top level, each stage will define its own agent.
environment { REGISTRY = "xxxx/master-metaspace" KUBE_CONFIG = "--namespace=master-metaspace --context=master" KUBE_YAML_PATH = "/home/jenkins/workspace/yaml/master-metaspace" // Assume that 'data' is defined elsewhere or injected as a parameter. BASE_WORKSPACE = "xxxxxxx" // 定义一个基础工作空间路径 }
stages { stage("GetCode") { agent { label "build01" } steps { script { checkout scm: [ $class: 'GitSCM', branches: [[name: env.branchName]], extensions: [[$class: 'CloneOption', depth: 1, noTags: false, shallow: true]], userRemoteConfigs: [[credentialsId: 'xxxx', url: env.gitHttpURL]] ] } } } stage("Docker Builds") { parallel { stage('Build dataloader-game-ucenter') { agent { label "build01" } when { environment name: 'dataloader', value: 'true' } steps { buildAndPushDockerImage("dataloader-game-ucenter", env.data, env.BASE_WORKSPACE) } } stage('Build datawriter-game-ucenter') { agent { label "build01" } when { environment name: 'datawriter', value: 'true' } steps { buildAndPushDockerImage("datawriter-game-ucenter", env.data, env.BASE_WORKSPACE) } } stage('Build game-ucenter') { agent { label "build01" } when { environment name: 'game-ucenter', value: 'true' } steps { buildAndPushDockerImage("game-ucenter", env.data, env.BASE_WORKSPACE) } } } } stage('Development Deployment') { parallel { stage("Deploy datawriter-game-ucenter") { when { environment name: 'datawriter-game-ucenter', value: 'true' } agent { label "huaweiyun-xx" } steps { deployToKubernetes("datawriter-game-ucenter") } } stage("Deploy dataloader-game-ucenter") { when { environment name: 'dataloader', value: 'true' } agent { label "huaweiyun-xx" } steps { deployToKubernetes("dataloader-game-ucenter") } } stage("Deploy game-ucenter") { when { environment name: 'game-ucenter', value: 'true' } agent { label "huaweiyun-xx" } steps { deployToKubernetes("game-ucenter-1") deployToKubernetes("game-ucenter-2") deployToKubernetes("game-ucenter-3") deployToKubernetes("game-ucenter-4") ............................ } } } } }}
// Define methods outside pipeline to avoid repetition
def buildAndPushDockerImage(String imageName, String tag, String workspacePath) { sh "cd ${workspacePath} && echo 'Current directory: $(pwd)'" // 使用基础工作空间变量 sh "cd ${workspacePath}/${imageName}&& docker build --build-arg NODE_ENV=$imageName -t $REGISTRY/$imageName:$tag ." withCredentials([usernamePassword(credentialsId: 'xxxxx', passwordVariable: 'dockerPassword', usernameVariable: 'dockerUser')]) { sh "docker login -u $dockerUser -p $dockerPassword $REGISTRY" sh "docker push $REGISTRY/$imageName:$tag" }}
def deployToKubernetes(String kubernetesComponent) { String templateFile = "${KUBE_YAML_PATH}/${kubernetesComponent}.tpl" String outputFile = "${KUBE_YAML_PATH}/${kubernetesComponent}.yaml" sh "sed -e 's/{data}/$data/g' $templateFile > $outputFile" sh "sudo kubectl apply -f $outputFile $KUBE_CONFIG"}


默认jenkins pipeline如上,我们有多个相似的游戏用户中心服务game-ucenter-*运行在Kubernetes集群中,它们都使用非常相似的Kubernetes YAML配置文件,配置文件之间的差异主要是一些标识符的不同(例如,服务的序号)。在传统的做法中,维护一系列几乎一样的模板文件(如game-ucenter-1.tpl, game-ucenter-2.tpl 等)将非常低效且易出错。

为了精简流程和提高效率,我们需要一个方法来通过单一模板生成多个配置文件,并由此部署多个不同的服务实例。


解决方案

使用Jenkins Pipeline中的sed命令和循环结构,我们可以从单一模板生成多个Kubernetes配置文件,并相应地部署每个服务实例。参照generate_templates.sh脚本

#!/bin/bash
# Define the name of the template file.TEMPLATE_FILE="game-ucenter.tpl"
# Check if the template file exists.if [ ! -f "$TEMPLATE_FILE" ]; then echo "Template file $TEMPLATE_FILE does not exist." exit 1fi
# Loop to create files from game-ucenter-2 to pvp-game-20 based on the template.for i in $(seq 1 20); do # Define the name of the new file. NEW_FILE="game-ucenter-${i}.yaml" # Copy the template to the new file. cp $TEMPLATE_FILE $NEW_FILE # Use 'sed' to replace 'game-ucenter-1' with 'game-ucenter-N' and save inline (-i option). sed -i "s/game-ucenter/game-ucenter-${i}/g" $NEW_FILE

echo "Created file: $NEW_FILE"done
echo "All files created successfully."


步骤 1: 定义Jenkins Pipeline

在我们的Jenkins脚本中,我们首先定义了基础环境变量和两个函数:buildAndPushDockerImagedeployToKubernetes。这些函数将用于构建Docker镜像并部署到Kubernetes


def buildAndPushDockerImage(String imageName, String tag, String workspacePath) {    sh "cd ${workspacePath} && echo 'Current directory: $(pwd)'" // 使用基础工作空间变量    sh "cd ${workspacePath}/${imageName}&& docker build --build-arg NODE_ENV=$imageName -t $REGISTRY/$imageName:$tag ."    withCredentials([usernamePassword(credentialsId: 'xxx', passwordVariable: 'dockerPassword', usernameVariable: 'dockerUser')]) {        sh "docker login -u $dockerUser -p $dockerPassword $REGISTRY"        sh "docker push $REGISTRY/$imageName:$tag"    }}
def deployToKubernetes(String kubernetesComponent) { String templateFile = "${KUBE_YAML_PATH}/${kubernetesComponent}.tpl" String outputFile = "${KUBE_YAML_PATH}/${kubernetesComponent}.yaml" sh "sed -e 's/{data}/$data/g' $templateFile > $outputFile" sh "sudo kubectl apply -f $outputFile $KUBE_CONFIG"}

步骤 2: 修改deployToKubernetes函数

接下来,我们需要修改deployToKubernetes函数,以便它能够接受组件名称,并使用单一模板文件创建具体的配置文件。

def deployToKubernetes(String kubernetesComponent, int instance=1, int totalInstances=1) {    // 检查实例值    if (instance < 1) {        error("实例数必须大于0")    }
// 根据 instance 的值来定义资源的名称和文件名 String nameSuffix = totalInstances > 1 ? "-${instance}" : "" // 总是添加后缀,除非只有一个实例 String outputFileName = "${kubernetesComponent}${nameSuffix}.yaml" String templateFile = "${KUBE_YAML_PATH}/${kubernetesComponent}.tpl" String outputFile = "${KUBE_YAML_PATH}/${outputFileName}" String nameReplacement = "${kubernetesComponent}${nameSuffix}"
sh """ cat "${templateFile}" | sed 's/{data}/${data}/g' | sed 's/name: ${kubernetesComponent}/name: ${nameReplacement}/g' | sed 's/app: ${kubernetesComponent}/app: ${nameReplacement}/g' > "${outputFile}" """
// 使用 KUBE_CONFIG 应用 Kubernetes 配置 sh "kubectl apply -f ${outputFile} ${KUBE_CONFIG}"}

对于单实例的业务,例如Deploy dataloader-game-ucenter,我们不需要传递实例编号。

stage("Deploy dataloader-game-ucenter") {    when { environment name: 'dataloader', value: 'true' }    agent { label  "huaweiyun-xx" }    steps {        deployToKubernetes("dataloader-game-ucenter")    }}

对于多实例。我这里生成 规则优点强迫症了。如果多实例我生成的规则要求符合game-ucenter-1,game-ucenter-2,game-ucenter-3……顺序,当单个实例的时候则保持原来的不加标签:

                stage("Deploy game-ucenter") {                    when { environment name: 'game-ucenter', value: 'true' }                    agent { label  "k8s-node-06" }                    steps {                        script {                          int instances = 2 // 假设我们有2个实例                          for (int i = 1; i <= instances; i++) {                            def componentName = "game-ucenter"                            deployToKubernetes("game-ucenter", i, instances)
} } } }

步骤 3: 准备模板文件

我们的模板文件game-ucenter.tpl将包含通用的Kubernetes服务或部署定义,使用占位符game-ucenter-1 game-ucenter-2来标识应该被替换的地方。

# game-ucenter-1.tpl (示例部分)apiVersion: apps/v1kind: Deploymentmetadata:  name: game-ucenterspec:  replicas: 1  strategy:    rollingUpdate:      maxSurge: 1      maxUnavailable: 0  selector:    matchLabels:      app: game-ucenter  template:    metadata:      labels:        app: game-ucenter    spec:      containers:        - name: game-ucenter          image: xxxx/xxx/game-ucenter:{data}          envFrom:          - configMapRef:              name: deploy          ports:            - containerPort: 80          resources:            requests:              memory: "4096M"              cpu: "2000m"            limits:              memory: "4096M"              cpu: "2000m"           livenessProbe:            httpGet:              scheme: HTTP              path: /test.html              port: 80            initialDelaySeconds: 20            periodSeconds: 120            successThreshold: 1            failureThreshold: 3          readinessProbe:            httpGet:              scheme: HTTP              path: /test.html              port: 80            initialDelaySeconds: 20            periodSeconds: 120      imagePullSecrets:                                                      - name: xxx---
apiVersion: v1kind: Servicemetadata: name: game-ucenter labels: app: game-ucenterspec: ports: - port: 80 protocol: TCP targetPort: 80 selector: app: game-ucenter
# ...

步骤 4: 执行Jenkins Pipeline

当Jenkins Pipeline运行到”Development Deployment”阶段时,它将循环创建和应用game-ucenter-1.yamlgame-ucenter-2.yaml的配置文件,从而部署2个game-ucenterdeployment服务实例。并保证单个实例的原有命名规则:

通过这一方法,我们不再需要为每个服务实例维护一个单独的模板文件,而是可以通过一个模板文件和Jenkins Pipeline的自动化来简化服务部署工作。这样做不仅提升了效率,也降低了出错的风险。

注意:

以上代码和命令为示例性质,可能需要根据您具体的Jenkins环境和Kubernetes集群进行相应的调整。在生产环境中部署之前,请确保进行充分的测试。


链接:https://blog.51cto.com/saynaihe/9029504

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