inbound-agent镜像 : https://hub.docker.com/r/jenkins/inbound-agent

1. 静态节点实践

首先，在Jenkins 中创建一个jnlp类型的agent，拿到连接所需要的认证和秘钥信息。

java -jar agent.jar -jnlpUrl http://192.168.1.200:8080/computer/buildtest01/jenkins-agent.jnlp -secret 047a2627be5ee128c1a93f281051acc7bbbbd5221dcb56ae9fa408a494e72c2f -workDir "/home/jenkins"

1.1 Docker静态节点

启动镜像，传递认证参数。

## 测试
docker run --init jenkins/inbound-agent -webSocket -url http://192.168.1.200:8080 -workDir=/home/jenkins 047a2627be5ee128c1a93f281051acc7bbbbd5221dcb56ae9fa408a494e72c2f buildtest01 
## 运行
docker run -itd --name buildtest01 jenkins/inbound-agent -webSocket -url http://192.168.1.200:8080 -workDir=/home/jenkins 047a2627be5ee128c1a93f281051acc7bbbbd5221dcb56ae9fa408a494e72c2f buildtest01

1.2 K8s部署静态节点

java -jar agent.jar -jnlpUrl http://192.168.1.200:8080/computer/buildtest02/jenkins-agent.jnlp -secret f8b870a1f3783261375485aa28053ad22c9289ba7bc32e4167712ce57fb6cab4 -workDir "/home/jenkins"

---
kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: jenkinsagent
  name: jenkinsagent
  namespace: devops
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: jenkinsagent
  template:
    metadata:
      labels:
        k8s-app: jenkinsagent
      namespace: devops
      name: jenkinsagent
    spec:
      containers:
        - name: jenkinsagent
          image: jenkins/inbound-agent
          securityContext:
            privileged: true
          imagePullPolicy: IfNotPresent
          resources:
            limits:
              cpu: 1000m
              memory: 2Gi
            requests:
              cpu: 500m
              memory: 512Mi
          env:
            - name: JENKINS_URL
              value: http://192.168.1.200:8080
            - name: JENKINS_SECRET
              value: f8b870a1f3783261375485aa28053ad22c9289ba7bc32e4167712ce57fb6cab4
            - name: JENKINS_AGENT_NAME
              value: buildtest02
            - name: JENKINS_AGENT_WORKDIR
              value: /home/jenkins/workspace

如果遇到了agent启动时的链接问题，可以参考在yaml中加上这个变量。即使用websocket的方式链接。

            - name: JENKINS_WEB_SOCKET
              value: true

2. 动态节点实践

2.1 Docker 动态节点

docker插件： https://plugins.jenkins.io/docker-plugin/
项目地址： https://github.com/jenkinsci/docker-plugin

Jenkins动态slave的配置，需要Jenkins调用Docker的接口完成的。我们需要开启Docker远程访问。

MacOS

docker 开启API远程访问 (mac) 参考文档： https://juejin.im/entry/5bdf04b06fb9a049e41223f1

docker pull bobrik/socat
docker run -d -v /var/run/docker.sock:/var/run/docker.sock -p 2376:2375 bobrik/socat TCP4-LISTEN:2375,fork,reuseaddr UNIX-CONNECT:/var/run/docker.sock

CentOS
编辑/usr/lib/systemd/system/docker.service

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock

systemctl daemon-reload
systemctl restart docker

当我们把上面的配置完成后，可以通过Curl命令进行基本的测试API。出现一下信息表示成功开启。

#curl -XGET http://127.0.0.1:2375/version
{"Platform":{"Name":"Docker Engine - Community"},"Components":[{"Name":"Engine","Version":"19.03.5","Details":{"ApiVersion":"1.40","Arch":"amd64","BuildTime":"2019-11-13T07:29:19.000000000+00:00","Experimental":"false","GitCommit":"633a0ea","GoVersion":"go1.12.12","KernelVersion":"4.19.76-linuxkit","MinAPIVersion":"1.12","Os":"linux"}},{"Name":"containerd","Version":"v1.2.10","Details":{"GitCommit":"b34a5c8af56e510852c35414db4c1f4fa6172339"}},{"Name":"runc","Version":"1.0.0-rc8+dev","Details":{"GitCommit":"3e425f80a8c931f88e6d94a8c831b9d5aa481657"}},{"Name":"docker-init","Version":"0.18.0","Details":{"GitCommit":"fec3683"}}],"Version":"19.03.5","ApiVersion":"1.40","MinAPIVersion":"1.12","GitCommit":"633a0ea","GoVersion":"go1.12.12","Os":"linux","Arch":"amd64","KernelVersion":"4.19.76-linuxkit","BuildTime":"2019-11-13T07:29:19.000000000+00:00"}

Jenkins配置

我们需要安装插件 Docker plugin

方式1：启动容器进行构建(无需连接master)

此处课程中没有测试出来…. 可能与环境有关….这种方式了解即可。

docker pull maven:3.8.1-openjdk-8-slim

dockerNode(dockerHost: 'tcp://192.168.1.200:2375', image: 'maven:3.8.1-openjdk-8-slim') {
    // some block
    sh "mvn -v"
    sh "sleep 5"
}

方式2：使用CLoud

配置云：节点管理-> CLoud-> Docker

Docker Cloud details信息填写：

Docker Host URI Docker主机信息(需要开启Docker配置)
- tcp://192.168.1.200:2375
- unix:///var/run/docker.sock
Connection Timeout 连接超时时间
Read Timeout 读操作超时时间（调大些，容易出现超时的情况）
Enabled 是否启用？默认否
Error Duration 错误的持续时间默认300 5分钟
Container Cap 容器数量负值或零，或2147483647都意味着“无限制” ,默认值100。

Docker Agent templates

Labels 节点标签
Enabled 是否启动默认否
Name 节点名称
Docker Image 镜像标签
Remote File System Root 远程文件系统根目录
用法自定义指定项目运行
Connect method 连接方式
- JNLP 推荐
  - User 运行用户
  - Jenkins URL jenkins地址
  - Idle timeout 空闲时间多少秒后杀死slave

SSH
Docker Container

Pull strategy 镜像下载策略
Pull timeout 镜像下载超时时间单位秒
Instance Capacity 实例数量

测试

node("jenkins-node"){
    echo "Hello world!"
    sh "sleep 20"
}

2.2 K8s部署动态节点

https://plugins.jenkins.io/kubernetes/

安装kubernetes插件（安装完成后最好重启一下）。
配置插件信息节点管理 > Cloud ->增加一个云。

制作Kubernetes证书

进入集群服务器 .kube/config
复制config文件中的certificate-authority-data内容，生成base64文件 ca.crt
- echo xxxxxx | base64 –d > ca.crt

Jenkins新建凭据
新建凭据 , Secret file.类型，将.kube/config文件上传上去。

将ca.crt 内容复制到服务证书key，选择证书凭据，测试连接。

测试流水线的模板：

pipeline{
    agent{
        kubernetes{
            label "test01"
            cloud 'kubernetes'
            yaml '''
---
kind: Pod
apiVersion: v1
metadata:
  labels:
    k8s-app: jenkinsagent
  name: jenkinsagent
  namespace: devops
spec:
containers:
  - name: jenkinsagent
    image: jenkins/inbound-agent
    imagePullPolicy: IfNotPresent
'''
        }
    }
    options {
        skipDefaultCheckout()
    }
    stages{
        stage("test"){
          steps{
            script{
              sh "sleep 3"
            }
          }
        }
    }
}

运行后能够，正常启动一个agent节点则正常。

3. 测试流水线

docker

安装 docker-pipeline 插件 https://plugins.jenkins.io/docker-workflow/
未安装插件导致的报错：

WorkflowScript: 3: Invalid agent type "docker" specified. Must be one of [any, label, none] @ line 3, column 9.
           docker { 
           ^

docker 启动的Jenkins ，默认容器中没有docker 命令。需要配置

+ docker inspect -f . maven:3.6.3-jdk-8
/var/jenkins_home/workspace/build-test-pipeline@tmp/durable-4746e7b2/script.sh: line 1: docker: command not found

docker run -itd --name jenkins \
-u root \
-p 8080:8080 \
-p 50000:50000 \
--privileged=true  \
-v /data/cicd/jenkins:/var/jenkins_home \
-v /var/run/docker.sock:/var/run/docker.sock \
-v /usr/bin/docker:/usr/bin/docker \
docker.io/jenkins/jenkins:2.277.1-lts-centos7

image, alwaysPull, args, containerPerStageRoot, customWorkspace, label, registryCredentialsId, registryUrl, reuseNode

pipeline {
    agent {
        node {
            label "master"
        }
    }
    options {
        skipDefaultCheckout true
    }
    stages {
        stage('Maven Build') {
            agent {
                docker {
                    image 'maven:3-alpine'
                    args  '-v $HOME/.m2:/root/.m2'
                }
            }
            steps {
                sh 'mvn clean package'
            }
        }
    }
}

DevOps学习路径【开源版本】

02-Jenkins动静态节点实践