SpringBoot与docker的结合的示例

最近一段时间，容器化成为了一种趋势。一台服务器可以虚拟成多个容器，同时提供服务，共享硬件资源，节约成本，容器化的翘楚就是docker，我司的所有微服务的发布都已经容器化。spring boot 也紧跟潮流，加入了docker的maven插件，可以通过执行命令来制作镜像。

本节的主要内容不是讲代码，而是讲这个docker插件。废话不多说，上pom

<plugin>

<groupid>com.spotify</groupid>

<artifactid>docker-maven-plugin</artifactid>

<version>0.4.12</version>

<configuration>

<imagename>spring-boot-docker-start</imagename>

<baseimage>java</baseimage>

<exposes>

<expose>8080</expose>

</exposes>

<entrypoint>["java", "-jar", "/${project.build.finalname}.jar"]</entrypoint>

<resources>

<resource>

<targetpath>/</targetpath>

<directory>${project.build.directory}</directory>

<include>${project.build.finalname}.jar</include>

</resource>

</resources>

</configuration>

</plugin>

imagename就是镜像的名称。baseimage是基础镜像，本地有使用本地的镜像，没有的话从远程仓库拉取，暴露容器内的8080端口，执行java -jar 命令，启动微服务。我们知道使用docker需要制定dockerfile文件，里面的元素完全通过maven插件的标签来体现了。还是有前提的，你得先安装好docker。讲解到这里，我们开始运行

第一步：执行mvn clean package docker:build创建生成镜像。

第二步：启动镜像docker run -it -p spring-boot-docker-start,看下容器内的日志

➜ spring-boot-docker-start git:(master) docker run -it -p spring-boot-docker-start

. ____ _ __ _ _

/\\\\ / ___'_ __ _ _(_)_ __ __ _ \\ \\ \\ \\

( ( )\\___ | '_ | '_| | '_ \\/ _` | \\ \\ \\ \\

\\\\/ ___)| |_)| | | | | || (_| | ) ) ) )

' |____| .__|_| |_|_| |_\\__, | / / / /

=========|_|==============|___/=/_/_/_/

:: spring boot :: (v1.3.5.release)

2018-03-25 08:41:56.274 info 1 --- [ main] com.shuqi.applicationmain : starting applicationmain on 075543f8f5b6 with pid 1 (/spring-boot-docker-start.jar started by root in /)

2018-03-25 08:41:56.287 info 1 --- [ main] com.shuqi.applicationmain : no active profile set, falling back to default profiles: default

2018-03-25 08:41:56.406 info 1

--- [ main] ationconfigembeddedwebapplicationcontext : refreshing org.springframework.boot.context.embedded.annotationconfigembeddedwebapplicationcontext

@126d28d3: startup date [sun mar 25 08:41:56 utc 2018]; root of context hierarchy

2018-03-25 08:41:58.356 info 1 --- [ main] s.b.c.e.t.tomcatembeddedservletcontainer : tomcat initialized with port(s): 8080 (http)

2018-03-25 08:41:58.382 info 1 --- [ main] o.apache.catalina.core.standardservice : starting service tomcat

2018-03-25 08:41:58.384 info 1 --- [ main] org.apache.catalina.core.standardengine : starting servlet engine: apache tomcat/8.0.33

2018-03-25 08:41:58.512 info 1 --- [ost-startstop-1] o.a.c.c.c.[tomcat].[localhost].[/] : initializing spring embedded webapplicationcontext

2018-03-25 08:41:58.512 info 1 --- [ost-startstop-1] o.s.web.context.contextloader : root webapplicationcontext: initialization completed in 2113 ms

2018-03-25 08:41:58.920 info 1 --- [ost-startstop-1] o.s.b.c.e.servletregistrationbean : mapping servlet: 'dispatcherservlet' to [/]

2018-03-25 08:41:58.928 info 1 --- [ost-startstop-1] o.s.b.c.embedded.filterregistrationbean : mapping filter: 'characterencodingfilter' to: [/*]

2018-03-25 08:41:58.937 info 1 --- [ost-startstop-1] o.s.b.c.embedded.filterregistrationbean : mapping filter: 'hiddenhttpmethodfilter' to: [/*]

2018-03-25 08:41:58.937 info 1 --- [ost-startstop-1] o.s.b.c.embedded.filterregistrationbean : mapping filter: 'httpputformcontentfilter' to: [/*]

2018-03-25 08:41:58.938 info 1 --- [ost-startstop-1] o.s.b.c.embedded.filterregistrationbean : mapping filter: 'requestcontextfilter' to: [/*]

2018-03-25 08:41:59.406 info 1 --- [ main] s.w.s.m.m.a.requestmappinghandleradapter : looking for @controlleradvice: org.springframework.boot.context.embedded.annotationconfigembeddedwebapplicationcontext@126d28d3: startup date [sun mar 25 08:41:56 utc 2018]; root of context hierarchy

2018-03-25 08:41:59.516 info 1 --- [ main] s.w.s.m.m.a.requestmappinghandlermapping : mapped "{[/hello],methods=[get]}" onto public java.lang.string com.shuqi.controller.hellocontroller.hello()

2018-03-25 08:41:59.523 info 1 --- [ 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)

2018-03-25 08:41:59.524 info 1 --- [ 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)

2018-03-25 08:41:59.584 info 1 --- [ main] o.s.w.s.handler.simpleurlhandlermapping : mapped url path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.resourcehttprequesthandler]

2018-03-25 08:41:59.585 info 1 --- [ main] o.s.w.s.handler.simpleurlhandlermapping : mapped url path [/**] onto handler of type [class org.springframework.web.servlet.resource.resourcehttprequesthandler]

2018-03-25 08:41:59.645 info 1 --- [ main] o.s.w.s.handler.simpleurlhandlermapping : mapped url path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.resourcehttprequesthandler]

2018-03-25 08:41:59.754 info 1 --- [ main] o.s.j.e.a.annotationmbeanexporter : registering beans for jmx exposure on startup

2018-03-25 08:41:59.834 info 1 --- [ main] s.b.c.e.t.tomcatembeddedservletcontainer : tomcat started on port(s): 8080 (http)

2018-03-25 08:41:59.838 info 1 --- [ main] com.shuqi.applicationmain : started applicationmain in 4.084 seconds (jvm running for 5.012)

[2018-03-25 08:41:59] server started!

启动成功。

第三步：输入docker ps看看容器内的8080端口被映射到了本机的哪个端口