docker maven 出错：Failed to execute goal com.spotify:docker-maven-plugin:...: Request error: POST https://192.168.99.100:2376/build?t=

Spring Boot项目构建docker镜像，出错Failed to execute goal com.spotify:docker-maven-plugin:0.4.13:build (default-cli) on project SpringBoot2: Exception caught: Request error: POST https://192.168.99.100:2376/build?t=mytest/SpringBoot2: 500: HTTP 500 Internal Server Error

出现这个错的原因确实出人意料——居然是因为大小写问题...

我是在pom.xml里加入了docker构建用的插件：

　　　　　　<plugin>
                <groupId>com.spotify</groupId>
                <artifactId>docker-maven-plugin</artifactId>
                <version>0.4.13</version>
                <configuration>
<!--                     <imageName>${docker.image.prefix}/${project.artifactId}</imageName> 这里取得是项目名字，我的项目名字是SpringBoot2，导致失败-->
                    <imageName>mytest/springboottest</imageName>
<!--                     <dockerDirectory>src/main/docker</dockerDirectory> -->
                    <dockerDirectory>./</dockerDirectory>
                    <resources>
                        <resource>
                            <targetPath>/</targetPath>
                            <directory>${project.build.directory}</directory>
                            <include>${project.build.finalName}.jar</include>
                        </resource>
                    </resources>
                </configuration>
            </plugin>

构建方式，请参考：http://spring.io/guides/gs/spring-boot-docker/