docker+Jenkins

结合Jenkins大体思路：将springboot应用打包并发布成docker镜像，然后再运行。Jenkins主要执行的步骤是：拉取代码--->打包--->发布镜像---->运行镜像

1. spring boot 应用配置

   添加下面maven插件：

   dockerfile 位置根据具体情况修改！！！

        <plugins>
               <plugin>
                   <groupId>org.springframework.boot</groupId>
                   <artifactId>spring-boot-maven-plugin</artifactId>
               </plugin>
               <plugin>
                   <groupId>com.spotify</groupId>
                   <artifactId>dockerfile-maven-plugin</artifactId>
                   <version>1.4.13</version>
                   <executions>
                       <execution>
                           <id>default</id>
                           <goals>
                               <goal>build</goal>
                               <goal>push</goal>
                           </goals>
                       </execution>
                   </executions>
                   <configuration>
                       <repository>${project.name}</repository>
                       <tag>${project.version}</tag>
                       <buildArgs>
                           <JAR_FILE>${project.build.finalName}.jar</JAR_FILE>
                       </buildArgs>
                       <dockerfile>./Dockerfile</dockerfile>
                   </configuration>
               </plugin>
           </plugins>
   

2. 编写docker file

   FROM openjdk:8-jre-slim
   MAINTAINER xuxueli
   
   ENV PARAMS=""
   
   ENV TZ=PRC
   RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
   
   COPY target/xxl-job-executor-0.0.1-SNAPSHOT.jar /app.jar
   
   ENTRYPOINT ["sh","-c","java -jar $JAVA_OPTS /app.jar $PARAMS"]
   
   

   只需要改变下target（打包完之后的包名）

3. 新建Jenkins应用，并配置好git信息。仓库地址和验证信息和分支等

image-20210312095650376.png

2. 加入maven构建

[图片上传中...(image-20210312095914050.png-98c522-1615859185694-0)]

image-20210312095759829.png

3. 设置maven的setting文件【非必须】

   因为默认的setting下载会很慢，所以需要更改setting文件

   a. 进入manage jenkins----> manage files

image-20210312095914050.png

b. 新增config

image-20210312095929282.png

c. 选择mave setting.xml，并提交

image-20210312100335611.png

    d. settting 复制进去

image-20210312100501205.png

4. 选择刚刚设置好的maven setting.xml,打开maven的高级设置

   maven 目标：clean -U -Dmaven.skip.test=true package

   image-20210312101451622.png

6. 添加脚本：

   docker stop xxl-job-executor
   docker start xxl-job-executor
   

7. 测试脚本，直接build，一步一个脚印，一行一行脚本调试

问题记录：

1. docker运行提示：

   Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/boot/SpringApplication

   原因：包没有引入

   解决方案：精简maven插件：

2. no main manifest attribute

   原因：

   1. plugins 中是按顺序执行的，顺序反了必然会出现问题。

   2. springboot结构不完整。需要有完整的父依赖（https://stackoverflow.com/questions/54867295/springboot-no-main-manifest-attribute-maven）

   3. maven执行springboot的repackge目标：mvn package spring-boot:repackage

   4. 或者maven添加插件：

      <plugin>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-maven-plugin</artifactId>
              <configuration>
                  <mainClass>com.places.Main</mainClass>
              </configuration>
      
              <executions>
                  <execution>
                      <goals>
                          <goal>repackage</goal>
                      </goals>
                  </execution>
             </executions>
      
      </plugin>
      

   5. springboot 打包运行成功要素

      3 things:
      - You have the parent entry in your pom.
      - Verify that your plugin is in the build portion of the pom.
      - You have a class with the @SpringBootApplicaion annotation.
      
      pom.xml:
      
      ...  
        <parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>2.1.8.RELEASE</version>
        </parent>
      
         <build>
          <plugins>
            <plugin>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
          </plugins>
        </build>
      ...
      And a class that looks something like this:
      
      @SpringBootApplication
      public class Application {
      
          public static void main(String[] args) {
              SpringApplication.run(Application.class, args);
          }
      
      }