Create Jenkins WorkflowMultibranchProject job with groovy init

Question

I am automating the configuration of Jenkins masters to get to a one-click instantiation. We have 6 standard jobs we create for each instance and I'd like to be able to create them via groovy.init.d scripts but haven't found examples for this type of job.

We use the cloudbees Bitbucket Team/Project plugin that ends up creating jobs of type WorkflowMultibranchProject with additional configuration to connect to our on-prem Bitbucket instance.

Does anyone have samples of creating such a job via groovy? Am I better off trying to use JobDSL to create the job (am doing that already for a Mother Seed job)

[UPDATE] : with the help of the answer below came up with a full sample creating an entire Bitbucket Team/Project Job: https://github.com/redfive/jenkins-init/blob/master/init.groovy.d/core-jobs.groovy

Answer 1

Having used Job DSL, I'm 50/50 undecided if it is easier compared to using Groovy (as Job DSL lacks support for some of the config options).

An example for the similar OrganizationFolder can be found in @coderanger's article on https://coderanger.net/jenkins/:

  // Create the top-level item if it doesn't exist already.
  def folder = jenkins.items.isEmpty() ? jenkins.createProject(OrganizationFolder, 'MyName') : jenkins.items[0]
  // Set up GitHub source.
  def navigator = new GitHubSCMNavigator(githubOrg)
  navigator.credentialsId = cred.id // Loaded above in the GitHub section.
  navigator.traits = [
    // Too many repos to scan everything. This trims to a svelte 265 repos at the time of writing.
    new jenkins.scm.impl.trait.WildcardSCMSourceFilterTrait('*-cookbook', ''),
    // We have a ton of old branches so try to limit to just master and PRs for now.
    new jenkins.scm.impl.trait.RegexSCMHeadFilterTrait('^(master|PR-.*)'),
    new BranchDiscoveryTrait(1), // Exclude branches that are also filed as PRs.
    new OriginPullRequestDiscoveryTrait(1), // Merging the pull request with the current target branch revision.
  ]
  folder.navigators.replace(navigator)

The next time when I set up an instance, I'd likely give that a try.