我在jenkinsfile中有以下阶段，其中参数名称是从for循环“ i”值派生的： 如何在运行时内插在运行时导出的参数值

stage ('Create new part'){
          steps {
             script{
                 sh "mkdir ${WORKSPACE}/inventories && touch ${WORKSPACE}/inventories/hosts"
                  for (i in (["db","pr","pl","ad","lo","log","jm","se","fo","me","he"]) ) {
                       if ("${params."'$i'_instances"}" == "3" && "${params."'$i'_disksize"}" > "80") {
                          sh "echo 'Entered if loop'" 
                          sh "echo '['$i'-servers]'>> ${WORKSPACE}/inventories/hosts"
                          for (j=1; j<=params.$i_instances; j++) {
                              sh "echo '${params.project_name}-${params.environment_name}-${$i_prefix}-$j target_fs="${params.$i_FS_TYPE}" percentage_fs="{params.$i_fs_percentage}"' >> ${WORKSPACE}/inventories/hosts"
                            }
                         }   
                   }
                }
            }
          }