Original approach was to upgrade one version of play at a time and keep all functionality. This turned out incredible difficult given all the interdependencies between libraries and scala version. See old branch: https://opensource.ncsa.illinois.edu/bitbucket/projects/CATS/repos/clowder/compare/commits?sourceBranch=refs%2Fheads%2F2.0&targetBranch=refs%2Fheads%2Fdevelop.

Currently working on this: Luigi Marini Rob Kooper Maxwell Burnette Todd Nicholson

New approach is as follows:

• Remove all unused and legacy code. This will be 2.0.
  • XML RDF export
  • Rabbitmq monitoring using manager API (Maxwell Burnette started on this)
  • Geostreams API (Todd Nicholson will do this ) - branch https://opensource.ncsa.illinois.edu/bitbucket/projects/CATS/repos/clowder/compare/commits?sourceBranch=refs%2Fheads%2Frefactor%2F2.0-remove-geostreams
  • Deprecated endpoints (Maxwell working on this)
  • Every plugin should become a Guice Trait + Implementation (2.1?)
    • For services that are not implemented, provide an no-op implementation
    • Enabled/disabled, is it in the config? Is it a common trait and the ability to provide implementation class in config file?
  • ??? (Add by end of this week Nov. 1st)
• Elasticsearch upgrade?
• New MongoDB implementation. This will be 3.0+.
  • Replace Salat and Cashbah with Java Mongo Driver and keep the rest as is
    • Mongo drivers
      • http://mongodb.github.io/mongo-java-driver/ (this might be our safest bet)
      • http://mongodb.github.io/mongo-java-driver-reactivestreams/
      • https://mongodb.github.io/mongo-scala-driver/
  • Split services in two layers.
    • Top layer has the common code that calls the other services. For example when removing a dataset also remove files.
    • Bottom layer is traits to do CRUD operations on resources and requires multiple implementations.
• Modify code to be compatible with newer versions of Playframework. 4.0+
  • Should jump straight to 2.7 or 2.6. We need to figure out which one. 
  • Migrate authentication / authorization:
    
    • https://github.com/mohiva/play-silhouette
• How do tests factor in? can we start writing them before the refactoring? For example unit tests of services vs play scala tests of controllers actions.
• Enforce style as part of this process. Using IDE? We should look at what rules and style software to use.
  • http://www.scalastyle.org/
  • Pick our preferred rules

PLUGINS

Here is a list of plugins that, as of 1/6/2020, nobody has created a pull request yet to turn into a service. Can any be deleted or ignored, and who is doing them in what order? 

• MailerPlugin (it was not clear if this plugin actually gets used to send email to me - Todd.)
• PolyglotPlugin
• PostgresPlugin
• RDFExporterPlugin 
• RDFExportService (implements plugin)
  • Since the RDF endpoints have been removed, can the RDF plugins be removed as well? 
  • Pull request created for removing these plugins (note added - 1/15/2020)
• SecureSocialTemplatesPlugin
• SpaceCopyPlugin 
  • Todd - will replace with value in conf. This plugin is simply enabled or not. (Pull request created)
• SpaceSharingPlugin
  • Todd - will replace with value in conf, again, either enabled or not. (Pull request created)
• StagingAreaPlugin
  • This plugin worked pretty much the same as SpaceCopy and SpaceSharing, so I replaced it with a value in the application.conf in the same pull request as those 2 plugins. (Todd, 1/7/2020). 
• TempFilesPlugin
• ToolManagerPlugin
  • Removed by Todd (pull request now open)
• VersusPlugin

Play 2.6 Upgrade

• Upgrade Play 2.2.0 to 2.2.6
• https://www.playframework.com/documentation/2.5.x/Migration23
• https://www.playframework.com/documentation/2.5.x/Migration24
  • http://www.silhouette.rocks/ - Secure Social replacement
    • example: https://github.com/adrianhurt/play-silhouette-credentials-seed
• https://www.playframework.com/documentation/2.5.x/Migration25
• https://www.playframework.com/documentation/2.6.x/Migration26

Sbt migration: http://www.scala-sbt.org/0.13/docs/Migrating-from-sbt-012x.html