karaf-maven-plugin制作本地feature仓库

项目中需要在karaf中集成cxf-dosgi-discovery-distributed特性，所以需要在karaf开启时启动cxf-dosgi-discovery-distributed的feature，只需要在etc/org.apache.karaf.features.cfg中加入如下的片段即可：

“mvn:org.apache.cxf.dosgi/cxf-dosgi/1.6.0/xml/features”和“cxf-dosgi-discovery-distributed”为加入的部分

featuresRepositories=mvn:org.apache.karaf.features/standard/3.0.3/xml/features,mvn:org.apache.karaf.features/enterprise/3.0.3/xml/features,mvn:org.ops4j.pax.web/pax-web-features/3.1.4/xml/features,mvn:org.apache.karaf.features/spring/3.0.3/xml/features,mvn:org.apache.cxf.dosgi/cxf-dosgi/1.6.0/xml/features

#
# Comma separated list of features to install at startup
#
featuresBoot=config,standard,region,package,kar,ssh,management,cxf-dosgi-discovery-distributed

上述配置以后，karaf启动时就会从maven仓库下载所需要的feature并启动。
但是这样需要每次都从maven仓库中取，网络状况不好的时候很费时。最好的方式是把这些feature都放在本地。幸好karaf的system目录就是专干这个的。可以把feature相关的bundle都放在system中，这样就不再需要去maven仓库中取了。

利用karaf-maven-plugin的features-add-to-repository即可实现：

<plugin>
    <groupId>org.apache.karaf.tooling</groupId>
    <artifactId>karaf-maven-plugin</artifactId>
    <version>3.0.3</version>
    <executions>
        <execution>
            <id>features-add-to-repo</id>
            <phase>generate-resources</phase>
            <goals>
                <goal>features-add-to-repository</goal>
            </goals>
            <configuration>
                <descriptors>
                    <descriptor>mvn:org.apache.cxf.dosgi/cxf-dosgi/1.6.0/xml/features</descriptor>
                    <descriptor>mvn:org.apache.karaf.features/standard/3.0.3/xml/features</descriptor>
                </descriptors>
                <features>
                    <feature>http-whiteboard</feature>
                    <feature>cxf-dosgi-discovery-distributed</feature>
                </features>
                <repository>target/features-repo</repository>
            </configuration>
        </execution>
    </executions>
</plugin>

生成的maven结构的目录会放在target/features-repo中，只需要把里面的目录原封不动拷贝到karaf的system目录下即可。下次启动时feature就会从这里面获取了。