Koji Maven Support
Koji Maven Support (hereafter referred to as Koji-Maven) is an attempt to bring the same security, auditability, and reproduceability to Java builds that Koji brings to rpm builds.
What is it?
Koji-Maven is a wrapper around the Maven build tool, in the same way Koji is a wrapper around the mock build tool. Koji-Maven manages the repository of jars from which Maven pulls build dependencies, and tracks the build environment, recording what jar files are downloaded into the build environment. Build output is added to the repository for use by subsequent builds, and build logs are stored centrally. A "wrapper" rpm can be generated that contains exactly the same jars generated by the Maven build, and can then be used by subsequent rpm-based builds. And rpm-based builds which generate jars can add those jars to the Maven repository for use by subsequent Maven builds.
How does it work?
Package Management
Koji-Maven manages Java artifacts (.jar, .war, .ear, etc. files) natively, in much the same way that Koji manages .rpm files. Koji-Maven extends the concept of a Koji build so it can be associated with both rpms and Java artifacts. These builds may then be added to a tag, and repositories can be created from groups of tags. For each tag associated with a build target, Koji-Maven can be configured to create a Maven repository, in addition to the yum repository. This repo will contain all Java artifacts associated with a build that is associated with that tag (or another tag in the group). Each tag can be configured to include only artifacts from the "latest" build of a given package (consistent with the yum repositories), or to include all versions of a package associated with the tag. This is required because a single Maven build may depend on more than one version of the same package. Once the repositories are created they are used by the builders for creating an environment suitable for building other packages.
Building
A Koji-Maven build environment is created the same way as a standard Koji build environment, by using mock to install a group of packages, including "maven2" (which will do the actual building), into a chroot.