Java development infrastructure at FMI

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Java development infrastructure at FMI

• Pekka Rantala
• FMI

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Components

• Four Open Source software components
• Eclipse IDE for developers
• Subversion version control (used by developers
  through Eclipse's Subclipse plugin)?
• Maven 2 for builds (mostly hidden from
  developers)?
• Plus Maven proxy for querying and caching
  internet and local repos
• Continuum for continuous integration building

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General architecture
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Day-to-day usage developer

• Developer commits code into SVN
• Continuum detects a change in the SVN repo and
• uses Maven to build the project as a side effect
• Maven installs the newly built component in the
  main FMI component repo, thus making the changed
  artifact visible for all other projects and
  webstart apps.
• The developer only sees the infra via Eclipse
  Subclipse is used to access SVN, and Maven is
  used locally as an external tool. Developer
  receives emails from Continuum if (s)he breaks
  the build (and subsequently another mail when the
  build is fixed)?

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Motivation the Great Refactoring

• A large-ish workstation project (on average five
  developers, maybe about a thousand java classes)
  was built as a monolithic Ant build ? builds were
  taking long and were very often broken
• The project was split up to consist of manageable
  chunks of code (about forty projects remained)?
• Building 40 projects as separate Ant builds is
  not feasible
• Maven-Continuum-Subversion interplay makes it
  fairly flexible to build components (artifacts)
  independently of each other
• Nowadays we have a little over 100 projects
  including common reusable components easily
  incorporable into any in-house project

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Benefits

• Maven strong points
• Easy management of dependencies (in-house built
  libraries and third party libraries)?
• Powerful extension mechanism for inheriting
  dependencies and other configuration from a
  project to another
• Build lifecycle is easily extended by creating
  one's own plugins (mojos)?
• Various reports (javadocs, source Xrefs etc.) are
  easily generated automatically

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Benefits

• For the developer
• ideally, the developer needs not be bothered
  about a project's build internals declaring
  dependencies is usually sufficient
• Building artifacts continuously and enforcing a
  commit early, commit often policy greatly
  reduces the risk of components running out of
  sync with each other

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Artifact versioning

• An artifact is the end product of a build a
  library, component, XML file or such. Conventions
  state that one project should produce one
  artifact
• An artifact under development is labeled as a
  SNAPSHOT and is by definition unstable (API is
  allowed to change at will) SNAPSHOTs are used
  at own risk.
• 0.7-SNAPSHOT becomes 0.7 during a disciplined
  release process (other projects may declare their
  dependencies to which ever version they like).
  Releases are final contract determines that a
  release of an artifact will not change

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Releases

1. When release criteria (API documentation, release
   notes in wiki, Unit tests run, ...) is met
2. Release Manager tells Maven to prepare and
   perform the release. Maven
3. checks out all code from SVN,
4. builds the project (running Unit tests),
5. tags it under SVN as a release
6. and upgrades the project's version number.
7. The new release and the new SNAPSHOT are
   available to other projects via the Maven proxy

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FMI utils Application metadb

• Stores metadata about FMI-built artifacts
  (available versions, bindings between FMI Service
  API components etc.) Metadata is communicated to
  the DB by way of an FMI-built Maven plugin during
  build
• Signs and stores FMI-built SNAPSHOT artifacts
  during build-time and other artifacts per request
  (implemented as a Servlet wrapper around Sun's
  jarsigner utility)?
• Based on the first two points offers dynamic
  composition of .jnlp files (Java Webstart)
  resolving all dependencies and checking the
  signing status of needed components (for instance
  the SmartMet II workstation is primarily started
  via javaws)?

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FMI utils POMBrowser

• Resolves projects' dependencies and dependency
  paths, evaluating formal release readiness.
• Draws a dependency graph of the current artifact
  and a dependency element for use in other projects

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FMI utils Repository browser

• Searches the local Maven repo for FMI projects
• Composes URLs to Maven built sites, Subversion
  views, APIs , wiki and the POMBrowser
• Offers rudimentary quality checks of project
  settings

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FMI utils Project creator

• Creates directories, Project Object Model file
  pom.xml and other skeleton files
• Imports the new project into SVN
• Notifies Continuum about a new project

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To come Open sourcing / collaborations

• It is planned that FMI may open for public
  access
• a part of the Subversion repository
• similarly, a public Maven repository for FMI
  built artifacts in the public domain.
• Common data and metadata handling components are
  good candidates for open sourcing
• The tools are in wide use Open sourcing issues
  should be easily solved.
• If the infra (including FMI utils) gathers enough
  interest, we may feel enough pressure to
  productise and release the utils and
  documentation publically.

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Resources

• Eclipse http//www.eclipse.org/
• Subversion http//subversion.tigris.org/
• Maven http//maven.apache.org/
• http//mvnrepository.com/ for searching
  publically available artifacts
• Continuum http//maven.apache.org/continuum/