Event Transformation

Available after v1.6.0

1. Lua Script: Executes user-defined Lua script to transform the event.

2. JQ Command: Evaluates JQ command to transform the event. We use https://github.com/itchyny/gojq to evaluate JQ commands.

Note

• If set, transformations are applied to the event before the filters are applied.

• Either a Lua script or a JQ command can be used for the transformation, not both.

• Only event data is available for the transformation and not the context.

• The event is discarded if the transformation fails.

Lua Script

apiVersion: argoproj.io/v1alpha1
kind: Sensor
metadata:
  name: webhook
spec:
  template:
    serviceAccountName: operate-workflow-sa
  dependencies:
    - name: test-dep
      eventSourceName: webhook
      eventName: example
      transform:
        script: |-
          event.body.message='updated'
          return event
  triggers:
    - template:
        name: webhook-workflow-trigger
        conditions: "test-dep"
        k8s:
          operation: create
          source:
            resource:
              apiVersion: argoproj.io/v1alpha1
              kind: Workflow
              metadata:
                generateName: webhook-
              spec:
                entrypoint: whalesay
                arguments:
                  parameters:
                    - name: message
                      # the value will get overridden by event payload from test-dep
                      value: hello world
                templates:
                  - name: whalesay
                    inputs:
                      parameters:
                        - name: message
                    container:
                      image: docker/whalesay:latest
                      command: [cowsay]
                      args: ["{{inputs.parameters.message}}"]
          parameters:
            - src:
                dependencyName: test-dep
                dataKey: body
              dest: spec.arguments.parameters.0.value

1. transform.script field defines the Lua script that gets executed when an event is received.

2. The event data is available to Lua execution context via a global variable called event.

3. The above script sets the value of body.message field within the event data to a new value called updated and returns the event.

4. The type of the event variable is Table and the script must return a Table representing a valid JSON object.

JQ Command

apiVersion: argoproj.io/v1alpha1
kind: Sensor
metadata:
  name: webhook
spec:
  template:
    serviceAccountName: operate-workflow-sa
  dependencies:
    - name: test-dep
      eventSourceName: webhook
      eventName: example
      transform:
        jq: ".body.message *= 2"
  triggers:
    - template:
        name: webhook-workflow-trigger-1
        conditions: "test-dep-foo"
        k8s:
          operation: create
          source:
            resource:
              apiVersion: argoproj.io/v1alpha1
              kind: Workflow
              metadata:
                generateName: webhook-
              spec:
                entrypoint: whalesay
                arguments:
                  parameters:
                    - name: message
                      # the value will get overridden by event payload from test-dep
                      value: hello world
                templates:
                  - name: whalesay
                    inputs:
                      parameters:
                        - name: message
                    container:
                      image: docker/whalesay:latest
                      command: [cowsay]
                      args: ["{{inputs.parameters.message}}"]
          parameters:
            - src:
                dependencyName: test-dep
                dataKey: body
              dest: spec.arguments.parameters.0.value

1. The above script applies a JQ command .body.message *= 2 on the event data which appends the value of .body.message to itself and return the event.

2. The output of the transformation must be a valid JSON object.