GitBucket/doc/auto_update.md

Automatic Schema Updating

GitBucket uses H2 database to manage project and account data. GitBucket updates database schema automatically in the first run after the upgrading.

To release a new version of GitBucket, add the version definition to the gitbucket.core.servlet.AutoUpdate at first.

object AutoUpdate {
  ...
  /**
   * The history of versions. A head of this sequence is the current GitBucket version.
   */
  val versions = Seq(
      Version(1, 0)
  )
  ...

Next, add a SQL file which updates database schema into /src/main/resources/update/ as MAJOR_MINOR.sql.

GitBucket stores the current version to GITBUCKET_HOME/version and checks it at start-up. If the stored version differs from the actual version, it executes differences of SQL files between the stored version and the actual version. And GITBUCKET_HOME/version is updated by the actual version.

We can also add any Scala code for upgrade GitBucket which modifies resources other than database. Override Version.update like below:

val versions = Seq(
  new Version(1, 3){
    override def update(conn: Connection): Unit = {
      super.update(conn)
      // Add any code here!
    }
  },
  Version(1, 2),
  Version(1, 1),
  Version(1, 0)
)