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
    
    

TWO APPROACHES – UPGRADE IN PLACE OR FRESH BUILD

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go through line by line in the "core" deps list and try to understand whether a dependency is missing because it's been superceded, or included because it's now no longer drawn in automatically via other deps etc etc.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

        implementation("org.grails.plugins:spring-security-core:${grailsVersion}")

        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.