The Log Traffic Policy action enables you to leverage ngrok’s eventing system to introduce observability into your traffic policy documents.

​
Configuration Reference

The Traffic Policy configuration reference for this action.

​
Supported Phases

  • on_tcp_connect
  • on_http_request
  • on_http_response

​
Action Type

log

​
Configuration Fields

​
metadata
map[string]any
Required
Supports CEL
A key-value map of metadata that you would like to include in your events for this action.

​
Behavior

​
Event logs

When this action is executed, the specified metadata will be collected on the tcp_connection_closed.v0 event under the traffic_policy.logs key.

​
Examples

​
Logging with CEL Interpolation

The following Traffic Policy configuration will log a message with the endpoint identifier for every request.

​
Example Traffic Policy Document

on_http_request:
  - actions:
      - type: log
        config:
          metadata:
            message: Log action executed.
            endpoint_id: ${endpoint.id}

​
Example Request

$ curl https://example.ngrok.app
Once the request has completed, and you have properly configured an event destination, you should see an event appear with the following payload: 
{
  "event_id": "ev_25X3yFS6TDkig1KDJWIc4nnJO0c",
  "event_type": "http_request_complete.v0",
  "event_timestamp": "2024-06-23T23:44:16Z",
  "account_id": "ac_2OtNvAlhso10Gx6a7eupzX3F98q",
  "object": {
    "traffic_policy": {
      "logs": [
        {
          "metadata": {
            "message": "Log action executed.",
            "endpoint_id": "ep_2bhsN2VP8W4pTkaMSrhyj0SRf8J"
          }
        }
      ]
    }
  }
}

​
Action Result Variables

The following variables are made available for use in subsequent expressions and CEL interpolations after the action has run. Variable values will only apply to the last action execution, results are not concatenated.
​
actions.ngrok.log.metadata
object
A key-value map containing metadata that was logged during the action. Each key represents a metadata attribute, and the value provides its corresponding details.