Creating source distribution in a componentized project

In a componentized project, functionality comes from different components. A full source distribution for such project needs to contain sources from each of these components. Hence it's somewhat challenging when it comes to creating a source distribution. Read on to find out one possible solution.

Let me give you a generic overview of the project structure first.

1. Our project is Java based & we use maven as our build tool
2. We have a core platform, pretty much similar to linux kernel.
3. We have components - Each of these components contain different functionality & are self sustainable. Each of these components contain documentation of its own. These documentation become automatically available when a UI page from a component is in use. (we call this context sensitive help/documentation)
4. When we want to build a product, we pack together,

• core platform
• selection of components
• Customized UI theming for the product
• Samples related to product
• Specific documentation related to product

Due to this nature of dynamism in a given product, it becomes challenging when creating source & documentation distributions to such products. Simple, yet ugly alternative is to have someone dedicated to create these distributions manually & keep an ever changing script to perform it.But its not a sustainable/cost effective work flow to a small team like ours. Hence we automated it. Rest of this blog post is on how to automate creation of source distribution. I will talk about the docs distro on some other post. We have included Maven source plugin as described here to root pom.xml of our projects. When a component is built, this plugin will pack the source of the component & upload it to maven repository.

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-source-plugin</artifactId>
                <version>2.0.4-wso2</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>jar</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>  

In our product build script(done using maven assembly plugin), we download these source artifacts(of which the product is consisted of),

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.0-alpha-4</version>
                <inherited>false</inherited>
                <executions>
                    <execution>
                        <id>unpack-foo</id>
                        <phase>package</phase>
                        <goals>
                            <goal>unpack</goal>
                        </goals>
                        <configuration>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>org.foo.bar</groupId>
                                    <artifactId>foo</artifactId>
                                    <version>SNAPSHOT</version>
                                    <type>zip</type>
                                    <overWrite>true</overWrite>
                                    <classifier>sources</classifier>
                                    <outputDirectory>target/sources</outputDirectory>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

unpack them to a folder structure of our choice, zip it back as our source distribution for a given product. This sure is a lengthy process, but has made it hell of lot easier when it comes to release times. When it comes to day-to-day building which does not require source/docs distributions, there are several tweaks to stop creation of these.