Spring Boot应用发布到Docker Spring Boot应用发布到Docker的实现
一书生VOID的博客 人气:0Spring官网上有一篇Getting Start,介绍了如何使用Docker发布Spring Boot应用,算是比较详细了,不过有些细节没有提及到,而且官网的入门手册是英文版。这里重新整理记录一下,算是给英文不好的小伙伴一个参考,也给自己留个备忘。
准备
需要的工具以及运行环境:
- JDK 1.8 or later
- Maven 3.0 +
- 你喜欢的IDE或其他文本编辑器
创建工程
首先,你需要创建一个Spring Boot工程,Spring Tool Suite和IntelliJ IDEA都自带插件可以创建,还有一种方式是从http://start.spring.io/上创建,推荐使用这种方式。填好表单中的Group Id
和Artifact Id
之后,点击Generate Project按钮就可以生成了,将下载后的工程导入到你喜欢的IDE中。
修改pom.xml文件,添加docker-maven-plugin:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>org.matrixstudio.springboot</groupId> <artifactId>docker</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>docker</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.2.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <docker.image.prefix>springio</docker.image.prefix> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <!-- Docker maven plugin --> <plugin> <groupId>com.spotify</groupId> <artifactId>docker-maven-plugin</artifactId> <version>0.4.3</version> <configuration> <imageName>${docker.image.prefix}/${project.artifactId}</imageName> <dockerDirectory>src/main/docker</dockerDirectory> <resources> <resource> <targetPath>/</targetPath> <directory>${project.build.directory}</directory> <include>${project.build.finalName}.jar</include> </resource> </resources> </configuration> </plugin> </plugins> </build> </project>
docker-maven-plugin插件用于将Spring Boot工程构建为Docker镜像:
- imageName表示Docker镜像名称,我们使用Docker的命名规范,命名为:springio/docker
- dockerDirectory表示Dockerfile的路径
- resource表示在构建时需要的资源文件,这些文件和Dockerfile放在一起,这里只需要Spring Boot生成的jar文件即可。
打开DockerApplication.java
文件,修改成如下内容:
package org.matrixstudio.springboot; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @SpringBootApplication @RestController public class DockerApplication { @RequestMapping("/") public String home() { return "Hello Docker World"; } public static void main(String[] args) { SpringApplication.run(DockerApplication.class, args); } }
编译并运行
执行如下命令运行Spring Boot工程:
mvn package && java -jar target/docker-0.0.1-SNAPSHOT.jar
打开浏览器,输入http://localhost:8080
,如果出现“Hello Docker World”说明运行成功。
注:运行上面的命令时,需要从Maven官方仓库中下载很多依赖包,国内网络不太稳定,下载速度较慢,可考虑使用第三方提供的镜像站,比如阿里的Maven镜像仓库。在pom.xml中加入下面配置:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>org.matrixstudio.springboot</groupId> <artifactId>docker</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <!-- Dependencies --> ...... <!-- Build --> ...... <!-- Aliyun repository --> <repositories> <repository> <id>central</id> <name>aliyun</name> <url>http://maven.aliyun.com/nexus/content/groups/public/</url> <releases> <enabled>true</enabled> </releases> </repository> </repositories> </project>
容器化项目
首先要确保你的机器上安装了Docker,如果你的Docker安装在一台Linux服务器上,你需要将上面的Spring Boot工程上传到该服务器上,下面的步骤假设你是在Linux环境上操作。
创建Dockerfile
Docker使用一个名为Dockerfile
的文件来指定image层,所以我们首先需要创建一个Dockerfile
文件,执行下面的命令创建Dockerfile
文件:
sudo tee src/main/docker/Dockerfile <<-'EOF' FROM frolvlad/alpine-oraclejdk8:slim VOLUME /tmp ADD docker-0.0.1-SNAPSHOT.jar app.jar RUN sh -c 'touch /app.jar' ENV JAVA_OPTS="" ENTRYPOINT [ "sh", "-c", "java $JAVA_OPTS -Djava.security.egd=file:/dev/./urandom -jar /app.jar" ] EOF
大概解释一下上面的命令:
- VOLUME指向了一个/tmp的目录,由于Spring Boot使用内置的Tomcat容器,Tomcat默认使用/tmp作为工作目录。效果就是在主机的/var/lib/docker目录下创建了一个临时文件,并连接到容器的/tmp。
- 将项目的jar文件作为app.jar添加到容器
- RUN表示在新创建的镜像中执行一些命令,然后把执行的结果提交到当前镜像。这里使用touch命令来改变文件的修改时间,Docker创建的所有容器文件默认状态都是“未修改”。这对于简单应用来说不需要,不过对于一些静态内容(比如:index.html)的文件就需要一个“修改时间”。
- 为了缩短Tomcat的启动时间,我们添加一个java.security.egd的系统属性指向/dev/urandom作为ENTRYPOINT。
构建Docker镜像
运行下面的命令构建Docker镜像:
mvn package docker:build
构建完成后,运行下面的命令查看:
sudo docker images
结果为:
REPOSITORY TAG IMAGE ID CREATED SIZE
springio/docker latest 7e2ba2f7e81e 2 minutes ago 195 MB
frolvlad/alpine-oraclejdk8 slim 00d8610f052e 4 days ago 167 MB
可以看到我们构建的镜像已经出现了,下一步就是运行该镜像。
运行Docker镜像
执行下面的命令来运行上一步构建的Docker镜像:
sudo docker run -p 8080:8080 -t springio/docker
如果不出意外,你将看到下面的输出内容:
. ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.5.2.RELEASE) 2017-03-08 03:34:59.434 INFO 6 --- [ main] o.m.springboot.DockerApplication : Starting DockerApplication v0.0.1-SNAPSHOT on 00eed53e6928 with PID 6 (/app.jar started by root in /) 2017-03-08 03:34:59.445 INFO 6 --- [ main] o.m.springboot.DockerApplication : No active profile set, falling back to default profiles: default 2017-03-08 03:34:59.752 INFO 6 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@4b9af9a9: startup date [Wed Mar 08 03:34:59 GMT 2017]; root of context hierarchy 2017-03-08 03:35:03.755 INFO 6 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http) 2017-03-08 03:35:03.807 INFO 6 --- [ main] o.apache.catalina.core.StandardService : Starting service Tomcat 2017-03-08 03:35:03.821 INFO 6 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.11 2017-03-08 03:35:04.042 INFO 6 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2017-03-08 03:35:04.043 INFO 6 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 4303 ms 2017-03-08 03:35:04.441 INFO 6 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/] 2017-03-08 03:35:04.455 INFO 6 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*] 2017-03-08 03:35:04.457 INFO 6 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*] 2017-03-08 03:35:04.468 INFO 6 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*] 2017-03-08 03:35:04.468 INFO 6 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*] 2017-03-08 03:35:05.110 INFO 6 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@4b9af9a9: startup date [Wed Mar 08 03:34:59 GMT 2017]; root of context hierarchy 2017-03-08 03:35:05.390 INFO 6 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto public java.lang.String org.matrixstudio.springboot.DockerApplication.home() 2017-03-08 03:35:05.402 INFO 6 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) 2017-03-08 03:35:05.404 INFO 6 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest) 2017-03-08 03:35:05.512 INFO 6 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2017-03-08 03:35:05.512 INFO 6 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2017-03-08 03:35:05.639 INFO 6 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2017-03-08 03:35:06.019 INFO 6 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup 2017-03-08 03:35:06.168 INFO 6 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http) 2017-03-08 03:35:06.183 INFO 6 --- [ main] o.m.springboot.DockerApplication : Started DockerApplication in 7.893 seconds (JVM running for 8.743) 2017-03-08 03:35:56.728 INFO 6 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring FrameworkServlet 'dispatcherServlet' 2017-03-08 03:35:56.728 INFO 6 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started 2017-03-08 03:35:56.774 INFO 6 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 43 ms
执行以下命令,查看正在运行的Docker容器:
sudo docker ps
可以看到已经有一个Docker容器在运行了:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 00eed53e6928 springio/docker "sh -c 'java $JAVA..." About a minute ago Up About a minute 0.0.0.0:8080->8080/tcp fervent_leavitt
现在输入http://localhost:8080可以查看到“Hello Docker World”结果。
如果要停止容器,可以执行下面的命令:
sudo docker stop 00e
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