js: Using javascript for transforms

Modified on Thu, 25 May, 2023 at 12:30 PM

Sometimes it's necessary to do really complex transformations, which jq cannot support (or if jq statements become too complex).

Below is an extract from a state showing how to use javascript:

  #
  # Snapshot the volumes and tag the snapshots with the change details from Servicenow.com
  #
  - id: snapshot-gcp-volumes
    # log: jq(.)
    log: "Creating snapshot for the volumes selected in ServiceNow"
    type: foreach
    array: 'jq( [ .result[] | select(.u_delete=="1") ] )'
    action:
      function: gcp-cli
      secrets: ["GCP_KEY", "GCP_PROJECT", "GCP_ACCOUNT"]
      input: 
        account: jq(.secrets.GCP_ACCOUNT)
        project: jq(.secrets.GCP_PROJECT)
        key: jq(.secrets.GCP_KEY | @base64 )
        commands:
        - command: gcloud compute disks snapshot jq(.u_volume_id) --zone=jq(.u_availability_zone) --format=json
    catch:
      - error: "*"
        transition: exception-catch
    transform: 
      result: |
        js(
            var newArray = new Array();
            snapsArray = data.return;
            changesArray = data.result;

            snapsArray.forEach(snapItem => {
              changesArray.forEach(changeItem => {
                if (snapItem.gcp[0].result[0].sourceDisk === changeItem['u_volume_id']) {
                  changeItem["u_snapshot_id"] = snapItem.gcp[0].result[0].name 
                  newArray.push(changeItem)
                }
              })
            })

            items = new Object();
            items.items = newArray;
            return items;
        )
    transition: delete-gcp-volumes

The jq statement can be replaced with a js statement as part of the workflow configuration.