Web Metrics

An HTTP request can be performed against some external service to obtain the measurement. This example makes a HTTP GET request to some URL. The webhook response must return JSON content. The result of the optional jsonPath expression will be assigned to the result variable that can be referenced in the successCondition and failureCondition expressions. If omitted, will use the entire body of the as the result variable.

  metrics:
  - name: webmetric
    successCondition: result == true
    provider:
      web:
        url: "http://my-server.com/api/v1/measurement?service={{ args.service-name }}"
        timeoutSeconds: 20 # defaults to 10 seconds
        headers:
          - key: Authorization
            value: "Bearer {{ args.api-token }}"
        jsonPath: "{$.data.ok}"

In the following example, given the payload, the measurement will be Successful if the data.ok field was true, and the data.successPercent was greater than 0.90

{
  "data": {
    "ok": true,
    "successPercent": 0.95
  }
}

  metrics:
  - name: webmetric
    successCondition: "result.ok && result.successPercent >= 0.90"
    provider:
      web:
        url: "http://my-server.com/api/v1/measurement?service={{ args.service-name }}"
        headers:
          - key: Authorization
            value: "Bearer {{ args.api-token }}"
        jsonPath: "{$.data}"

NOTE: if the result is a string, two convenience functions asInt and asFloat are provided to convert a result value to a numeric type so that mathematical comparison operators can be used (e.g. >, <, >=, <=).

Optional web methods

It is possible to use a POST or PUT requests, by specifying the method and body fields

  metrics:
  - name: webmetric
    successCondition: result == true
    provider:
      web:
        method: POST # valid values are GET|POST|PUT, defaults to GET
        url: "http://my-server.com/api/v1/measurement?service={{ args.service-name }}"
        timeoutSeconds: 20 # defaults to 10 seconds
        headers:
          - key: Authorization
            value: "Bearer {{ args.api-token }}"
          - key: Content-Type # if body is a json, it is recommended to set the Content-Type
            value: "application/json"
        body: "{\"key\": \"string value\"}"
        jsonPath: "{$.data.ok}"

!!! tip In order to send in JSON, you have to encode it yourself, and send the correct Content-Type as well. Setting a body field for a GET request will result in an error.