Upgrading Grails 5 to Grails 6

Initial things (Proper writeup to follow)

  • profiles are gone, use create-plugin or create-restapi from grails CLI (Steve says create-restapi may be best for plugins, with a changed up publishing block...?)

  • Versions used

    • Grails version 6.1.1

    • Gradle version 7.6.3

    • Java version 17.0.6-tem

    • Groovy version 3.0.11


Fresh build

  • Use grails cli to start a new grails 6 application with the right name.

  • Ensure gradle wrapper properties using 7.6.3 and set networkTimeout=10000

  • Move everything except gitignore and README from grails cli into a "service" directory, since this is the shape our modules are previously

  •  In build.gradle

    • Comment out "application" block

    • Comment out java sourceCompatibility block

    • Copy across

      • Group

      • Plugins/repositories

      • Configurations

      • "Custom deps" which definitely don't intefere with the bootstrapped grails 6 deps

      • Buildscript

    • NOTE - buildProperties no longer exists so for now comment out the generate descriptors blocks. Needs some input from Steve on how to proceed. (THIS NEEDS SORTING BEFORE RELEASE)

    • ./gradlew clean to check everything builds

    • Then work through dependencies in original app, cross referencing to new app's ones, and vice versa. Make changes, additions and comment out unnecessary ones

      • It is IMPORTANT to do this in both directions. There may be newer grails 6 dependencies that supercede older ones, so go through line by line in the "core" deps list and try to understand whether a dependency is missing because it's been superceded, or included because it's now no longer drawn in automatically via other deps etc etc.

      • The "custom dependencies" list can likely be pulled over verbatim though.

      • dependencies block:

        • Check grails gradle plugin version lines up with grailsVersion

        • Change hibernate5 plugin over to

          classpath "org.grails.plugins:hibernate5:$gormVersion"

          - ensure gormVersion exists (see below)

        • Change plugin views-gradle over to

          classpath "org.grails.plugins:views-gradle:3.1.2" /// Uh oh, this is breaking in grails-okapi
      • Possible exceptions

        • move spring-security core into the "proper" dependencies block and bump version up to grails version


          Was in place to handle security issues present in grails 5

        • make sure web-toolkit and grails okapi are on grails6 versions (TBD on release)

    • MAKE SURE you copy across the profile declaration. This is no longer supplied by the CLI, so we need to make sure its there.

    • On that note, delete the grails cli yaml file

    • Copy over bootJar.enabled stuff and eclipse block

    • May need to remove anything referencing configScript, as this appears to have been removed

    • Wrap the generateDescriptors task in

since there has been a change to the buildProperties task in grails 6.

  • Ensure HikariCP dep is on 5.1.0, and change application.yml (And any other profile ymls) datasource properties to just:

The rest is superfluous at this point, and the defaults are performant

  • AT THIS STAGE, it may be beneficial to copy across the .git dir, and to set up a branch for your changes

  • Copy over grails-app directories one by one, and also src folder and anything else that has been removed

  • For apps gradle.properties

    • Copy across everything but the grailsVersion and grailsGradlePluginVersion from existing repo (ENSURE that groovy version lines up though)

    • Grails gradle plugin version should == grailsVersion

    • Gorm version to 8.0.3

Upgrade in place (Much faster and seemingly equivalent)

  • Bump gradle wrapper to 7.6.3, set networkTimeout=10000 and make same changes to gradle.properties as above

  • Work through build.gradle in the same way as above

  • gradlew clean and run.