searchJenkinsBuildLogs.groovy

//Returns a list of Jobname: BuildNumbers that contain the term provided
def searchLogsForTerm(term) {  
  def folders = { item ->
  item instanceof jenkins.branch.OrganizationFolder
  }

Jenkins.instance.items.findAll(folders).collect { organizationFolder -> organizationFolder.items}.flatten()
  .collect { workflowMultiBranchProject -> workflowMultiBranchProject.items }.flatten()
  .collect { workflowJob -> 
  	 def matchingBuilds = workflowJob.builds.findAll { build -> build.log.contains(term) }
     matchingBuilds.collect { build -> println "$workflowJob.fullName: $build.displayName"}
 }
  
}